Bacteroidetes and Firmicutes, and in the genus level, Prevotella and Bacteroides, were predominant, with Prevotella accounting for 20–30% of the relative abundance. As GA increased, a significant increase in the relative abundance of Bacteroidetes (P for trend < 0.001) and decrease in Proteobacteria (P for trend = 0.049) was observed in the phylum level. In the genus level, as GA increased, Prevotella (P for trend < 0.001) and Bacteroides (P for trend = 0.002) increased significantly, whereas Enterococcus (P for trend = 0.020) decreased. Compared to the control group, the meconium of infants that later developed NEC/FI had significantly lower alpha diversities but similar beta-diversities. Furthermore, the NEC/FI group showed a significantly lower abundance of Bacteroidetes (P < 0.001), and higher abundance of Firmicutes (P = 0.034). To conclude, differences were observed in the composition of the first passed meconium in preterm and term infants that later develop NEC/FI compared to those that did not. The primary aim of this study was to investigate the compositional differences of the first passed meconium microbiome in preterm and term infants, and the secondary aim was to compare the meconium microbiomes of preterm and term infants that later developed necrotizing enterocolitis (NEC)/Feeding intolerance (FI) compared to those that did not develop NEC/FI. During the study period, a total of 108 preterm and term newborns' first passed meconium occurring within 72 hours of birth were collected and microbiome analyzed. Meconium microbiomes showed a disruption in the percentages of the core microbiome constituents in both the phylum and genus levels in infants born < 30 weeks of gestational age (GA) compared to those born ≥ 30 weeks of GA. In the phylum level,  In the last few decades, improvements in the survival rate of preterm infants have been observed . The manThe intestinal microbiota performs several functions, including maturation of the immune system, regulating immune response, protection against the invasion of opportunistic pathogens, and mediating hormonal regulation . Prior tThe preterm gut microbiome undergoes early disruption before achieving bacterial maturation. Gestational age at birth, representing the timing of first microbial exposure, is known to be significantly associated with the microbial composition including biomass and diversity of meconium in preterm infants ,15. In fIn order to understand how the composition of the gut microbiome in the immediate perinatal period may affect the clinical course of preterm and term infants, the primary aim of this study was to investigate the composition of the first passed meconium microbiome in Korean preterm and term infants. The secondary aim was to compare the meconium microbiomes of preterm and term infants that later developed NEC/FI versus those that did not develop NEC/FI.This was a prospective study carried out at a neonatal intensive care unit (NICU) of a tertiary referral university hospital located in Seoul, Korea. Preterm and term infants admitted to the NICU during May 2021 to February 2022 were included as study participants. The inclusion criteria were as follows: (1) first meconium stool sample obtained within 72 hours of birth during the study period, (2) admitted to the NICU regardless of the GA at birth, (3) transferred to the NICU immediately after birth for any symptoms requiring intensive care, and (4) obtained informed consent from the legal guardians. Exclusion criteria were as follows: (1) transferred to the NICU after being admitted to the nursery or another hospital, and (2) first meconium stool passed 72 hours or more after birth. Immediately upon passage, 1–2 mL (maximum 3 mL) of the infant’s first passed meconium was collected and stored at −20 °C. The specimens were then transferred to a deep freezer set at −80 °C until DNA was extracted for microbiome analyses. The clinical course and progression of the infants included in the study were surveyed until death or discharge. Demographic and clinical data, including GA, birth weight, history of sepsis, and postnatal hospital outcomes were obtained. The patients were divided into two groups: NEC/FI group comprised 26 (24.1%) infants that were diagnosed with NEC/FI during the course of prospective monitoring, and the control group consisting of 82 infants (75.9%) that did not present with any GI  symptoms during the NICU admission period. The study was approved by the Ethics Committee of Seoul St. Mary’s Hospital, The Catholic University of Seoul, Korea (IRB no. KC21TISI0329). All legal guardians of the study participants gave approval and signed informed consent forms for study participation. DNA was extracted using TIANLONG ®-nucleic acid extraction kit (for stool DNA/RNA extraction)  then determined concentration and purity using nanodrop spectrophotometer. The target region (V3-V4) was amplified using PCRBIO VeriFi Mix  and 16S-amplicon primer  at 95 °C for 3 min hot start followed by 25 cycles of 95 °C for 30 s and 55 °C for 30 s, 72 °C for 30 s with a final elongation step of 72 °C for 5 min. The V3-V4 target region reverse primer (5'TCGTCGGCAGCGTCAGATGTGTATAAGAGACAGCCTACGGGNGGCW-GCAG3’) and forward primer (5'GTCTCGTGGGCTCGGAGATGTGTATAAGAGACAGGACT-ACHVGGGTATCTAATCC3’) were used according to the guideline ‘Preparing 16S Ribosomal RNA Gene Amplicons for the Illumina MiSeq System’ .The amplified DNA subsequently were purified automatically in Nucleic Acid Extractor (TianLong Science and Technology Co.) using MagListo™ PCR/Gel Purification Kit , then the size and concentration were determined using Qsep100 . Purified samples were then standardized to 8 ng per reaction  and Index PCR was performed to attach in dual indices and Illumina sequencing using PCRBIO VeriFi Mix  and Nextera ® Index kit V2 Set A  at 95 °C for 3 min hotstart followed by 8 cycles of 95 °C for 30s and 55 °C for 30 s, 72 °C for 30 s with a final elongation step of 72 °C for 5 min. After indexing, the final library was cleaned up using MagListo™ PCR/Gel Purification Kit (Bioneer®) before quantification. DNA size and concentration were again measured using Qsep100 (Bioptic®) and Qbit flex fluorometer (Invitrogen®). After Qbit and Qsep measurements were completed, the mixing volume value was calculated then the PCR product was pooled into a microtube. After mixing, the final pooled library concentration and size were checked using Qbit and Qsep. The counts per reaction for each microbiome species was recorded. Libraries were prepared using MiSeq ® Reagent Kit V3 600 cycles kit (Illumina®), pooled libraries were denatured with NaOH 0.2 N, then diluted with hybridization buffer before sequencing, PhiX was used as an internal control for each run. DNA were pooled and sequenced on an Illumina Miseq platform according to the manufacturer’s standard instruction, sequencing data of bacterial variability sites (V3-V4) were analyzed with 16S metagenomics app. Analysis was performed on Quantitative Insights into Microbial Ecology 2  . DenoiseNEC was defined as stage II or above, according to the modified Bell’s staging classification grade , which iPreterm infants were defined as infants born < 37 weeks of gestational age, late preterm as GA 34 to <37 weeks, moderately preterm as GA 32 to <34 weeks, very preterm as GA 28 to <32 weeks, and extremely preterm as GA < 28 weeks . Small ft test, one-way ANOVA or Wilcoxon rank sum test depending on the normality of the variable being tested. More specifically, we compared the microbiome concentrations in the NEC group versus controls using the student’s t test . The logistic regression analysis was used to find the P for trend. The alpha diversity was calculated using Shannon’s diversity index, and beta diversity was plotted using Principal Coordinate Analysis of Bray–Curtis dissimilarity. Differences in categorical variables are compared using the chi-square or Fisher’s exact test. A univariate and multivariate analyses was carried out on all possible perinatal factors associated with NEC/FI. A p value of <0.05 was considered statistically significant.For descriptive statistics with demographic data and concentration and continuous variables were presented as means and standard deviation (SD) while categorical variables were presented as percentages and frequencies. For inferential statistics, continuous variables were compared using the P = 0.003)  and mean birth weight was 2,305.9g (SD ± 863.0). A total 83.3% (n = 90/108) of the patients were born via caesarean section, and 88.9% (n = 96/108) were male . A total= 0.003) . Bacteroidetes and Firmicutes were dominant in the first meconium microbiomes , and Proteobacteria decreased significantly as GA increased (P for trend = 0.049). In the genus level, as gestational age increased, Prevotella (P for trend < 0.001) and Bacteroides (P for trend = 0.002) increased significantly as GA increased, whereas Enterococcus (P for trend = 0.020) decreased as GA increased , an analysis of the relationship between GA and relative abundance of the phyla ncreased . P < 0.001), birthweight (P < 0.001), antenatal steroid use (P = 0.003), congenital infection (P = 0.010), RDS (P = 0.002), and intraventricular hemorrhage (IVH) above grade II (P = 0.021) were factors associated with NEC/FI. However, in the multivariate analysis, after adjusting for confounding, none of these factors were independently significantly associated with NEC/FI in this cohort of patients  were diagnosed with NEC or FI. Of these, 22 were preterm infants, and 4 were term infants. All possible perinatal and postnatal clinical factors associated with an increased risk for NEC/FI were investigated [ were diapatients . P = 0.030, respectively), however, similar beta diversities   c.The gut microbiota is a group of microorganisms, mainly bacteria, yeast, fungi, bacteriophages, and other viruses, as well as protozoa and archaea, which form a complex ecosystem in the human GI tract ,28,29. MBacteroidetes and Firmicutes, constituted majority of the microbiota of the neonatal meconium, and as the GA increased, a significant increase in the relative abundance of Bacteroidetes and decrease in Proteobacteria was observed. A study from Germany also showed that GA was significantly associated with the composition of meconium from very preterm infants, and the most abundant phyla included Firmicutes, Bacteriodetes, Proteobacteria, and Actinobacteria [Prevotella and Bacteroides were the predominant species, with Prevotella’s relative abundance accounting for 20-30% of the gut microbiome. Whereas in healthy adults, the two main phyla—Firmicutes and Bacteroidetes—constitute over 90% of the gut microbiota, followed by Actinobacteria and Proteobacteria [The two phyla, bacteria . Our stubacteria ,32. Bifidobacterium and Bacteroides, and Clostridium [Bacteroides are associated with increased gut diversity and faster intestine maturation and natural childbirth has been shown to be significantly related to microorganisms reflecting the mother’s vaginal flora, such as Bacteroides, Lactobacillus, and Prevotella [Prevotella and Bacteroides were the most prevalent, accounting for about 50% of the core microbiome. However, because 83.3% (n = 90) were born via caesarean section, Lactobacillus was not a predominant genus in the meconium of the infants in our study. Upon delivery, infants are exposed for the first time to a variety of microbes from various sources which lead to an establishment of the infants’ gut microbiome. Recent studies have shown that the predominant early colonizers of infant’s gut are maternal fecal bacteria, mainly stridium ,33,34,35evotella ,37. In tBacteroidetes, and higher abundance of Firmicutes and other microbes were observed. Firmicutes, Streptococcaceae, and Enterococcaceae are known to predominate in adults with lower diversity gut microbiota [One of the most devastating gastrointestinal emergencies and a major cause of mortality in very low birth weight infants (VLBWI) is NEC. Furthermore, FI is also a frequently faced problem in many neonatal intensive care units (NICUs). Prenatal and postnatal factors, such as placental insufficiency, chorioamnionitis, gut ischemia, altered bacterial colonization, viruses, and blood transfusions, presumably disrupt the mucosal barrier, which may trigger inflammatory reactions in the immature intestines of preterm infants . This stcrobiota . Lower dcrobiota ,39,40,41Polynucleobacter, Gp1, and Prevotella appeared in greater abundance in meconium of preterm infants with adequate birth weight for GA [Prevotella was positively correlated with GA, suggesting that the abundance of Prevotella has an important role in the growth and development of preterm infants. In the study on meconium microbiome and its relation to neonatal growth and head circumference catch-up in preterm infants, t for GA . In our Escherichia-Shigella and a lower proportion of Bacteroides compared with the those that did not have FI [Bacteroides in preterm infants with lower GA, suggesting that Bacteroides is a part of the healthy gut microbiome. Perturbation of the gut microbiota may promote overgrowth of pathobionts increasing the risk of infections and inflammation in the gut [Enterococcus, Enterobacter, and Klebsiella [Klebsiella, Streptococcus, Staphylococcus, Enterococcus, and Ureaplasma, and Kluyvera. The first moments of life are known to contribute to the formation of an NEC-associated microbiota [The recent study conducted by Liu et al. on early gut microbiota in very low and extremely low birth weight preterm infants with feeding intolerance showed that the meconium samples of the FI group had higher proportions of γ-proteobacteria and  have FI . Althoug the gut . In a stebsiella . In thiscrobiota , howeverIn this study, there were six cases of placental abruption and 14 cases of PROM, meaning that these infants may have been exposed to the vaginal microbiota in utero, and subsequently affecting the results of the gut microbiome in these subjects. Due to the small number of subjects, further analyses were difficult. However, a study on 8 preterm neonates in Indonesia reported that PROM and mother’s diet influenced the meconium microbiome . FurtherSaccharomyces, Malassezia, and Candida [When compared with bacteria, the healthy human gut mycobiome is lower in biomass compared to bacteriome biomass. However, the roles of mycobiomes are increasingly recognized as important, whether it be beneficial or harmful. The gut mycobiome is known to be dominated by  Candida , and the Candida . FurtherThis study had a few limitations the sample size of the study groups was relatively small. However, to date, this study contains one of the largest cohort of neonates, from GA 22 to 40. Secondly, although not conclusive, studies have shown evidence of sex related difference in the gut microbiome . Other sBacteroidetes was observed as gestation age increased. Infants with NEC/FI had significantly lower alpha diversities, and a significantly higher counts of pathobionts such as Klebsiella, Streptococcus, Staphylococcus, Enterococcus, Ureaplasma, and Kluyvera were observed. To conclude, differences were observed in the composition of the first passed meconium in preterm and term infants that later developed NEC/FI compared to those that did not. These findings fuel the need to understand disease pathogenesis and develop novel and significant microbiota for earlier therapeutic and preventative strategies for vulnerable preterm babies in further research.In summary, this study showed that low diversity dysbiosis was observed in the initial gut microbiomes of infants born premature, below 30 weeks of GA, and an increasing abundance of


Elevated levels of maternal cortisol have been hypothesized as the intermediate process between symptoms of depression and psychosocial stress during pregnancy and adverse birth outcomes. Therefore, we examined associations between cortisol levels in the second trimester of pregnancy and risks of three common birth outcomes in a nested case–control study.n = 3,019), from which we selected all cases with preterm birth (n = 64), low birth weight (n = 49), and small-for-gestational age , and 260 randomly selected controls, among the participants who provided a single awakening saliva sample in approximately gestational week 19 in 2012–2016. Multivariable linear and logistic regression was performed to assess the associations between continuous and categorized cortisol levels and the selected outcomes.This study was embedded in the PRIDE Study  seemed to be associated with SGA , in particular among girls  in an exploratory analysis.The results of this study showed no suggestions of associations between maternal awakening cortisol levels in mid-pregnancy and adverse birth outcomes, except for an increased risk of SGA. Common adverse birth outcomes, including preterm birth, low birth weight, and small-for-gestational age (SGA), are associated with neonatal mortality and long-term health problems, including neurodevelopmental impairments, respiratory and gastrointestinal complications, and higher sympathetic activity, which is considered a risk factor for cardiovascular disease –4. ThereCortisol is the end metabolite of the hypothalamic–pituitary–adrenal (HPA) axis and is essential in normal brain development . ThroughSeveral biological mechanisms have been proposed for linking elevated maternal cortisol levels to infant birth weight. Fetal exposure to elevated cortisol levels may dysregulate fetal autonomic nervous system activity and result in a high degree of calorie expenditure by mobilizing fetal energy stores through glycogenesis . AlternaThe results of previous studies on the associations between elevated maternal cortisol, fetal growth, and gestational age at birth were inconsistent , 20–23. As preterm birth, low birth weight, and SGA occur frequently, more research is needed to understand the etiology of these adverse birth outcomes and the potential role of maternal elevated cortisol levels during pregnancy therein. Using the ‘Meet in the Middle’ approach , 25, we This study was embedded in the PRegnancy and Infant DEvelopment (PRIDE) Study , 32, an Participants of the PRIDE Study were asked to optionally donate a single awakening saliva sample after completing the second prenatal questionnaire. Participants who agreed to do so received a Salivette  for saliva collection by regular mail. Samples were taken within 10 min after awakening on a working day, and before brushing teeth, eating, drinking, or smoking. The women were asked to record the date, time of awakening, and time of saliva collection. All samples were returned to the research site in a special envelope for biological materials by regular mail . The saliva samples were immediately stored at − 20 °C upon return. Samples that were received within 14 days after sampling and collected within 1 month after completing the second prenatal questionnaire were considered eligible for this study.g. The concentration of cortisol in the samples was determined using the Cortisol free in Saliva ELISA Kit was used . A total of 50 µL of the saliva sample, the standard reagent, and the control reagent was dispensed in microtiter wells. In addition, 50 µL of a cortisol-horseradish peroxidase conjugate for binding to the coated antibody, after which the wells were incubated at room temperature for 60 min. Subsequently, they were rinsed 3 times with 300 µL diluted wash solution and 200 µL of substrate solution was added. Again, the wells were incubated for 30 min at room temperature and 50 µL of stop solution was added to each well. The absorbance of each well was determined with a microtiter plate calibrated reader at 450 ± 10 nm within 15 min.We used a previously described method to determine the cortisol concentration in the saliva samples selected . At LDN From the PRIDE Study participants who completed the second prenatal questionnaire between April 2012 and May 2016 and provided an eligible saliva sample, we selected all cases with preterm birth (< 37 weeks of gestation), low birth weight (< 2500 g), and/or SGA  . These c2), parity (0 vs ≥ 1 previous birth), smoking during pregnancy, the presence of depressive symptoms based on the Edinburgh Depression Scale with a cut-off value of 10 [Descriptive statistics were used to describe the characteristics of the women included in this nested case–control study. Using linear regression analysis, crude and adjusted β coefficients with 95% confidence intervals (CI) were estimated for the associations between maternal salivary cortisol levels and the adverse birth outcomes. These models were adjusted for potential confounders that were identified a priori by means of literature review, including maternal age , pre-pregnancy Body Mass Index In exploratory analyses, we stratified by infant sex to examine the potential effects that the sex of the infant might have on the associations between maternal cortisol levels and the selected birth outcomes. When < 5 cases were exposed, only crude ORs with Fisher exact 95% CIs were calculated using Episheet  instead From the 3019 PRIDE Study participants who completed the second prenatal questionnaire in the study period, 1728 (57.2%) donated a saliva sample , low birth weight , and SGA , low birth weight , and SGA . The results of the stratified analyses on the categorical exposure variables are shown in Table After stratification by infant sex in the exploratory analyses, we did not observe associations between continuous maternal cortisol levels and preterm birth  and SGA. In the exploratory analyses, this risk of SGA was only increased among female infants, just as the risk of preterm birth, but these analyses relied on small sample sizes, resulting in unstable effect estimates.Although cortisol has repeatedly been hypothesized as one of the biological intermediates linking prenatal psychosocial stress to adverse birth outcomes –8, studiIn the same prospective cohort study of 2810 women, an association was observed between high morning cortisol levels (≥ 90th percentile) and an increased risk of SGA, concordant with our findings. Several potential pathways underlying the associations between elevated maternal cortisol levels and adverse birth outcomes have been suggested, including dysregulation of the fetal autonomic nervous system , vasocoStrengths of this study include the nested case–control design with embedding in a large prospective cohort study. Due to this design, we were able to include a relatively large number of cases compared to previous smaller studies , 23, 41.A limitation of the current study is the collection of only a single awakening saliva sample to determine the cortisol level, whereas multiple measurements during the day or on consecutive days might be preferred. In a previous study validating this approach, however, we showed that a single awakening salivary sample could reliably distinguish between women having normal and elevated cortisol levels . NeverthThe results of this nested case–control study showed no indications that maternal cortisol levels in mid-pregnancy are strongly associated with increased risks of preterm birth and low birth weight, but they may be associated with an increased risk of SGA. Infant sex seemed to influence this association. These findings help to understand the etiology and the onset of the occurrence of adverse birth outcomes and contribute to growing knowledge of the complex biological pathways linking maternal psychosocial problems to adverse birth outcomes.


To examine the potential for bias in the estimate of under-5 mortality due to birth defects recently produced by the WHO and the Maternal and Child Epidemiology Estimation research group.Systematic analysis.We examined the estimated number of under-5 deaths due to birth defects, the birth defect specific under-5 mortality rate, and the per cent of under-5 mortality due to birth defects, by geographic region, national income and under-5 mortality rate for three age groups from 2000 to 2019.The under-5 deaths per 1000 live births from birth defects fell from 3.4  3.1–3.8) in 2000 to 2.9 (UI 2.6–3.3) in 2019. The per cent of all under-5 mortality attributable to birth defects increased from 4.6% (UI 4.1%–5.1%) in 2000 to 7.6% (UI 6.9%–8.6%) in 2019. There is significant variability in mortality due to birth defects by national income level. In 2019, the under-5 mortality rate due to birth defects was less in high-income countries than in low-income and middle-income countries, 1.3 (UI 1.2–1.3) and 3.0 (UI 2.8–3.4) per 1000 live births, respectively. These mortality rates correspond to 27.7% (UI 26.6%–28.8%) of all under-5 mortality in high-income countries being due to birth defects, and 7.4% (UI 6.7%–8.2%) in low-income and middle-income countries.While the under-5 mortality due to birth defects is declining, the per cent of under-5 mortality attributable to birth defects has increased, with significant variability across regions globally. The estimates in low-income and middle-income countries are likely underestimated due to the nature of the WHO estimates, which are based in part on verbal autopsy studies and should be taken as a minimum estimate. Given these limitations, comprehensive and systematic estimates of the mortality burden due to birth defects are needed to estimate the actual burden. Estimates from WHO are compiled and represented systematically for country groups of interest.The limitations of the WHO estimates for mortality due to birth defects are thoroughly described and considered in the context of birth defects and the rapid decline of under-5 mortality.This study is limited in that estimates of mortality due to birth defects from the WHO are not compared with other similar estimates such as those produced by the Global Burden of Disease study.This study did not examine estimated mortality for specific types of birth defect.Birth defects  are a group of structural or functional conditions that occur in utero. Birth defects can be identified prenatally, at birth or later in life. Causes of these conditions are multifactorial and can incorporate genetic, behavioural and environmental factors, but in many cases, the causes of birth defects are unknown. Birth defects impact affected individuals and their families, including mortality, morbidity, the cost of care and individual and family well-being.Since the mid-2000s, there have been several efforts to estimate the burden of under-5 mortality due to birth defects by different groups. Modelled estimates for all countries were first developed in 2006 by the March of Dimes in a collaboration with the WHO.10An additional effort to estimate causes of mortality in children under 5, including the mortality due to birth defects among newborns age 0–27 days) and older children (28 days or 1 month to 59 months), has been ongoing since 2008, led by the Maternal and Child Epidemiology Estimation (MCEE) group in collaboration with the WHO. Its most recent update covers all WHO member states for the years 2000–2019.7 days anWe describe here the burden of under-5 mortality due to birth defects as currently estimated by the MCEE and the implications for health policy and planning. We also describe the limitations of these estimates. In light of these limitations, we describe the need for less biased estimates of the burden of birth defects  and make a call to action to the public and international health community to produce these estimates.In order to estimate cause-specific mortality for children under 5, the MCEE uses data from several distinct sources. The first is from vital registration systems, collected and maintained by the WHO. Cause of death data from vital registration covers approximately 40% of countries worldwide. However, vital registration does not generally capture a large portion of all under-5 deaths because countries with vital registration are generally high income and have fewer deaths among children under-5 years.The second primary data source for the MCEE estimates of under-5 mortality due to birth defects is based on results from verbal autopsy studies in areas without high-quality vital registration. The MCEE conducted a systematic review of published verbal autopsy studies that reported at least two causes of death for samples representative of the general population in areas with high neonatal and under-5 mortality, from 1980 to 2018. This review identified studies with population representative samples, such as those identified in large household surveys. In general, these deaths did not occur in health facilities or with skilled medical attendance. The cause of these deaths is determined with the best available information, which is obtained from a verbal autopsy interview with family or caregivers,The MCEE research group has published their methodology for estimated cause-specific mortality for children under 5 in detail.2We summarised the MCEE estimates for deaths due to birth defects as both the number of deaths and the per cent of neonatal, 1–59 month, and under-5 mortality. We also examined the mortality rate per 1000 live births for each of these three age groups by WHO six regions  and by u10.1136/bmjopen-2022-067033.supp1Supplementary datahttps://github.com/amulick/MCEE-u5mort2019.There were no patients involved in this study, and results were not disseminated to patients or patient families. All estimates and source data are publicly available at In 2000, under-5 deaths due to birth defects across all countries were estimated to be 452 600  4 08 900–5 02 500). In 2019, under-5 deaths due to birth defects dropped to 404 000 (95% UI 3 67 600–4 55 700). The under-5 deaths per 1000 live births from birth defects fell from 3.4 (95% UI 3.1–3.8) in 2000 to 2.9 (95% UI 2.6–3.3) in 2019. Conversely, the per cent of all under-5 deaths attributable to birth defects increased from 4.6% (95% UI 4.1%–5.1%) in 2000 to 7.6% (95% UI 6.9%–8.6%) in 2019 . Across Estimates for deaths due to birth defects among children under-5 by high-income countries and LMICs are shown in A snapshot of overall country contributions to the per cent of under-5 deaths due to birth defects in 2019 is depicted in The actual trends in under-5 mortality due to birth defects (rather than the estimated trends) are driven by two primary factors: the prevalence at birth and care after birth. Prevalence at birth is impacted by exposure to risk factors and preventive measures, preconception care and genetic counselling and availability and uptake of screening during pregnancy, including elective termination of pregnancies (TOP).Despite the limitations, the MCEE estimates suggest that under-5 deaths due to birth defects are in decline, paralleling the overall decline in under-5 mortality. As advances in child survival are made globally and other underlying drivers of under-5 mortality are addressed , MCEE estimates suggest that mortality due to birth defects is assuming a larger proporation of under-5 mortality, as indicated by the increasing global per cent of under-5 deaths due to birth defects from 2000 to 2019. In 2000, birth defects were estimated to be the seventh highest cause of under-5 mortality globally, while in 2019, they were fifth. This increase in the proportion of under-5 deaths due to birth defects over time is largely attributable to reductions in deaths due to infectious causes such as diarrhoea, pneumonia, malaria, measles, HIV, sepsis and meningitis.17Improvements in under-5 survival over the past 20 years are demonstrated by declining mortality rates in both high-income countries and LMICs, although estimated mortality due to birth defects declined more slowly in general in LMICs and is not declining in all regions. Estimated trends may be sensitive to the quality of source information and changes in data quality over time as well as choices made in the estimation process. Some actual decrease over time in the mortality due to birth defects is also likely reflected in the MCEE estimates. In general, health systems have made improvements since 2000,20While the overall proportion of deaths due to birth defects is much higher in high-income countries, the absolute burden of under-5 mortality due to birth defects disproportionately impacts LMICs because the death rate from birth defects is more than two times as high than in high-income countries. The burden of birth defects relative to other causes of under-5 mortality in LMICs is also likely to increase as infectious causes such as acute respiratory infections and diarrheal diseases decline. High-income countries in general have much lower rates of mortality due to infectious diseases, contributing to their higher percentage of under-5 deaths being due to birth defects. Estimated mortality rates from birth defects were lower in high-income countries compared with LMICs (1.29 vs 3.03 deaths per 1000 live births). This difference is likely underestimated, given that high-income countries generally have their own vital registration data, while many estimates for LMICs are derived from verbal autopsy studies.There are also differences in regional burden estimates that are likely due to the limitations of MCEE estimates derived from verbal autopsy studies. In 2000, the estimated mortality rate due to birth defects was similar in Europe, the Americas, the Western Pacific and the Eastern Mediterranean regions  but lower in Southeast Asia and Africa (3.2 and 2.1 per 1000 live births), despite the true birth prevalence likely being similar across regionsThe MCEE estimates should be considered the minimum lowest estimate for deaths attributable to birth defects and should not be used for estimating total burden of under-5 mortality attributable to birth defects in countries with modelled estimates. Verbal autopsy studies are used by the MCEE to derive estimates of cause-specific mortality in high under-5 all-cause mortality areas, and verbal autopsies in general have several important limitations related to birth defects. A verbal autopsy is a structured interview between a trained interviewer and a caregiver to the deceased, who generally are not trained to recognise birth defects among children or newborns apart from externally visible or otherwise obvious anomalies.24Relative to causes of deaths reported from verbal autopsies, causes reported by vital registration systems are more standardised across countries, because they are based on medical certification of deaths and mapped to ICD codes. However, vital registration systems may underestimate mortality due to birth defects in some cases.The MCEE estimates are developed separately from estimates related to the burden of birth defects estimated by other groups, including those by the GBD project.Our examination of the WHO estimates of under-5 mortality is limited. Our analysis did not include an examination of specific types of birth defects, as MCEE estimates are not currently produced for cause-specific mortality at a high enough resolution for such comparison. In addition, although other estimates for the mortality due to birth defects are available, notably from GBD, we have not systematically compared WHO/MCEE estimates to those of GBD, or to earlier estimates from the WHO and the March of Dimes.The MCEE has developed a useful set of estimates related to the burden of mortality among children under-5 related to birth defects, suggesting decreases in the rate of under-5 mortality due to birth defects since 2000 and increases in the per cent of under-5 mortality due to birth defects. However, both the MCEE-estimated rate and per cent of under-5 mortality due to birth defects are underestimated and represent only a minimum. More comprehensive estimates of this burden are needed for the most effective health system planning. The ideal estimates should encompass all deaths due to birth defects, including stillbirths and children older than 5, and they should not be subjected to the limitations of verbal autopsies. The best estimates would also have input from LMICs who are screening for and diagnosing birth defects and who may benefit from technical guidance in building capacity in this area. These estimates should also be developed to cover the recent time period, employ the latest methods to maximise transparency and replicability and incorporate the most recent data available from surveillance systems consistently across areas. Surveillance systems and estimates of the mortality burden of birth defects should not rely on verbal autopsies. Such estimates are a critical contribution to national, regional and global planning as the population affected by birth defects becomes a more prominent mortality burden among children under 5 years.10.1136/bmjopen-2022-067033.supp2Supplementary data


Preterm newborn nutrition affects postnatal skeletal growth and bone mineralization, but studies have not yet fully concluded the relationship between nutrition and osteopenia. This study was intended to investigate the impact of nutritional factors on osteopenia in preterm newborns.This is a case–control study with babies born with gestational age ≤ 32 weeks in a high-risk maternity hospital, between 2018 and 2019. The population consisted of 115 newborns, being 46 cases (40%) and 69 controls (60%). Disease outcome was based on serum alkaline phosphatase levels > 900UL/l and hypophosphatemia < 4 mg/dl. Gestational data at birth and clinical and nutritional follow-up data during 8 weeks postnatally were assessed. Variables were assessed using regressive logistic models.p = 0.035). Higher calcium intake, compared to controls, also increased the probability of disease occurrence , while the presence of a partner  and the shortest time using sedatives  were protective factors associated with osteopenia. Extremely low birth weight , sepsis  and invasive ventilatory support  were risk factors.Preterm infants who were fed pasteurized fresh human milk with acidity ≥ 4 ºDornic are 5.36 times more likely to develop osteopenia (Acidity and high calcium intake are the main nutritional factors associated with osteopenia of prematurity. Further studies on the use of human milk with lower acidity, recommendation and nutritional supplementation of calcium should be accomplished to guide prevention strategies in newborns at risk for osteopenia during hospital stay. Prematurity is a phenomenon that has been increasing worldwide and has been associated with osteopenia. Birth before the intrauterine period of greatest incorporation of nutrients into the bone matrix results in the partial or complete loss of the optimal stage of acquisition of mineral reserves . TherefoGlobally, about 10% of births are preterm. In Brazil, the prematurity rate reaches 11.9%, which is above the world average . The NorIn recent years, the longer survival of PTNB and the parallel increase in osteopenia cases has raised clinical interest in terms of the social costs and the future quality of life of preterm infants with some degree of bone impairment. Early in life, they may present fractures and rickets  and, in The optimization of nutrition in the postnatal period is capable of affecting not only the immediate growth and development of these newborns, but also producing effects in the long term . ResearcThis is a case–control study with preterm newborns admitted to the Neonatal Intensive Care Units of the Assis Chateaubriand Maternity School, a high-risk reference university institution, located in the capital of the State of Ceará, born from January 2018 to December 2019.A total of 115 newborns were selected as the study population, 46 cases and 69 controls. Cases and controls included all newborns, during the study period, with gestational age less than or equal to 32 weeks at birth and length of stay greater than or equal to 8 weeks, excluding surgical newborns, those with incomplete medical records, chromosomal abnormalities, congenital anomalies, bone diseases, inborn errors of metabolism and born to diabetic mothers, if fetal macrosomia.Clinical data on the puerperal woman and the newborn were collected from the puerperal woman’s medical record, using a structured form with the following items: gestational data, data on the newborn at birth and data on the newborn’s clinical and nutritional follow-up. All clinical and nutritional variables were assessed by means of daily follow-up of medical prescriptions, diagnostic updates and nutritional behaviors for 8 weeks after birth.The presence or absence of osteopenia, diagnosed through biochemical assay, was considered a dependent variable. All preterm newborns underwent biochemical screening for alkaline phosphatase and phosphorus at 3 weeks of postnatal life, being reassessed every 15 days. In any biochemical screening, PTNB with serum alkaline phosphatase levels above 900UL/l and hypophosphatemia below 4 mg/dl were diagnosed with the disease.The optimized kinetic method at 405 nm was used to determine alkaline phosphatase, while the ultraviolet method was used to determine inorganic phosphorus. The ALP 405–AA Liquid Line–Wiener® and Phosfatemia–UV AA–Wiener® reagent kits were used. The methods were held on a biochemical analyzer, CMD800iX1 model, manufactured by Wiener Lab Group.Independent variables of exposure included the supply of pasteurized fresh human milk with acidity greater than or equal to 4º Dornic, determined by physicochemical analysis, average intake of calories, protein, calcium, phosphorus, zinc and vitamin D, use of parenteral nutrition for more than 14 days, achievement of full enteral feeding  for more than 14 days, use of nutrient formula and nutritional supplementation of calcium, phosphorus, zinc and vitamin D.Variables related to the puerperal women , the newborns at birth  and the period of hospital stay  were also collected.Weight at birth and during hospital stay was collected with the newborn naked and in a dorsal decubitus position, and then assessed on a Balmak Baby ELP-25BB® electronic scale. During hospital stay, measurements followed the same daily weighing schedule, avoiding the bias of weight change throughout the day. The newborn’s nutritional status was assessed according to weight by corrected gestational age, using the Intergrowth-21 growth curve .Regarding the nutritional therapy protocol, parenteral nutrition was installed in the first 24 h of life in newborns weighing less than 1500 g, through the peripheral route, if the osmolarity is lower than 900 mOsm/L, or the central route, if the osmolarity is higher or equal to 900 mOsm/L, per umbilical catheter (PICC). The water quota of parenteral nutrition started with 60 to 80 ml/kg/day, progressing to 10 ml/kg/day and remaining with 150 ml/kg/day, being suspended when the enteral diet supplied 2/3 of the water needs.In the absence of abdominal distention and presence of intestinal noises and/or meconium elimination, enteral nutritional therapy was started in an early trophic way by gavage, until oral maturity, complete suction-swallow-breathing coordination and absence of respiratory discomfort, allowing the breastfeeding or oral feeding.During hospitalization, the newborns received raw, pasteurized human milk, with or without additives, or infant formula. The type of diet offered depended on the gestational age at birth, volume, availability of human milk offered by the institution's milk bank, availability of puerperal milking and clinical evolution.When necessary, and on medical advice, PTNBs received oral calcium, phosphorus, zinc and vitamin D supplementation. Calcium and phosphorus were supplemented in the form of tricalcium phosphate (50 mg/ml and 25 mg/ml), zinc chelate (2 mg /ml) and vitamin D at a concentration of 900 IU/ml. In parenteral nutrition, the patient receives supplementation of phosphate (1mMol), calcium (0.5 mEq/ml), amino acids (10 g/100 ml), and lipids (20 g/100 ml).2 test and bivariate logistic regression, and then used in the multivariate analysis to investigate the factors associated with the occurrence of the disease, through logistic regression and backward stepwise method. Initially, the variables associated with the outcome in the bivariate analysis that presented a significance level ≤ 0.2 were included in the model, corresponding to their level of determination . The insertion of each independent variable in the multivariate analysis occurred according to the constructed hierarchical theoretical model, which considered four blocks of causal determination . The characteristics of the newborn at birth and during the early postnatal life were grouped at the higher level (intermediate level I); and, at the distal level, the maternal characteristics that are more distantly related to the disease under study were included.p ≤ 0.1 were maintained in the final model and remained as an adjustment factor for the variables in the hierarchically inferior blocks. The variables that presented p < 0.05 in the final model as statistically significant were considered as factors associated with osteopenia of prematurity. The magnitude of the effect of each variable was estimated by calculating the Odds ratio and its respective 95% confidence intervals (CI). All analyses were performed using the SPSS statistical program, version 20.0.The variables included in each level of determination that presented This study was approved by the Research Ethics Committee of the Assis Chateaubriand Maternity School, CAAE 36,357,120.9.0000.5050, complying with the ethical criteria of Resolution 466/12, under Opinion number 4.246.798. The authors declare that all methods were carried out in accordance with relevant guidelines and regulations. The informed consent of the subjects and legal guardians was exempt by the Research Ethics Committee of Federal University of Ceará, in agreement with the Brazilian law resolution no. 466, of December 12, 2012.p < 0.001).Our population consisted of 115 newborns, 46 cases (40%) and 69 controls (60%). Female and male newborns constituted 53% and 47% of the study population, respectively. Most (67%) were born by means of cesarean delivery, with gestational age and average birth weight of 29 weeks (± 2.24) and 1.146 kg (± 0.36). As for the biochemical tests, during hospital stay, newborns diagnosed with osteopenia had average serum values of 1400UL/l (± 463) of alkaline phosphatase and 4.56 mg/dl (± 0.98) of phosphorus, higher than the control group ; p < 0.001] and lower APGAR index in the first minute of life ; and, throughout hospital stay, it is associated with the use of invasive ventilatory support for a prolonged time , presence of sepsis  and bronchopulmonary dysplasia .Regarding the newborns, the results of the bivariate analysis show that osteopenia is associated with worse conditions at birth, such as extreme prematurity , the use of parenteral nutrition  and full enteral feeding for more than 14 days . Nutritional supply also showed a difference between cases and controls, where the higher caloric intake  and the higher vitamin D intake  were protective factors, while the higher calcium intake  and the higher phosphorus intake  were risk factors.As for the nutritional aspects, in the bivariate analysis, osteopenia is associated with the intake of pasteurized fresh human milk with acidity greater than or equal to 4º Dornic , as well as the use of sedatives in the newborn for a shorter time . The probability of developing the disease was higher in newborns with extremely low birth weight , who developed sepsis during hospital stay  and who used, for a long time, invasive ventilatory support .After multivariate analysis and adjustments, the variables that remained in the final model of causal determination can be seen in Table p = 0.035). The higher calcium intake, compared to the control group, also increased the probability of disease occurrence   vs. 13 days (± 12.9), tely 38% . In additely 38% . TherefoThis study also demonstrated the difficulty of providing nutritional support according to the recommendations. According to the findings, this nutritional inadequacy seems to be related to the lower volume of diet offered, which also reflects a lower mineral supply and contributes to the occurrence of osteopenia. As shown by Chen et al. , reducedGrowth can also be considered an important indicator of bone mineralization . MonitorAs for the maternal aspects, the results found show that the chances of developing osteopenia are lower in newborns conceived by married women. Puerperal women who gave birth to preterm babies experience difficulties, such as, for example, stress (due to prematurity and low birth weight), separation from the binomial, discomfort with the environment of the neonatal unit, feeling of doubt, fear, sadness and anguish. All these situations undermine the family coexistence and dynamics, in addition to interfering with the production and maintenance of lactation and the desire to breastfeed and/or express human milk . TherefoThis support is structured in the care at home, with the other children, in the shared information and social experiences, so that the puerperal woman can step away from external reality and engage in the care of the newborn . In lighRegarding birth-related risk factors, it is observed that PTNBs with osteopenia have lower gestational age, birth weight and APGAR in the first minute of life . In thisPTNB also have an intestinal microbiome profile that makes them more vulnerable to infections and metabolic complications . As withAnother important issue is that the hypophosphatemia present in osteopenia causes muscle weakness, impairing exercise performance and leading to immobility . In moreFinally, the main limitation of the study is the absence of imaging tests, considered the gold standard in the assessment of osteopenia. Despite the widespread recognition of the disease, there is still no unified approach to diagnosis. Different markers are studied in the screening for osteopenia, although there is no agreement regarding their clinical use . AlkalinThe study showed an incidence of 40% of the disease, which is within the range reported in the literature. Although it is suggested that early diagnosis based on biochemical tests may overestimate cases of osteopenia, our result corroborates a recent study by Angelika et al. , which fAnother limitation is based on the type of study performed. As data collection took place retrospectively, it was not possible to assess relevant variables for the study, such as food intake and nutritional deficiencies of puerperal women during pregnancy. However, as far as the authors are aware, this is the first study that assessed the human milk acidity as a qualitative aspect associated with osteopenia of prematurity. In addition, a monocentric study was carried out, where the newborns followed the same nutritional protocol and were followed-up daily from birth to 8 weeks after birth.This study brings up important contributions in terms of directing strategies for prevention and control of osteopenia in preterm newborns. It is concluded that the main nutritional factors associated with the disease were acidity and high calcium intake. It launched a relevant theme for further studies on the use and distribution of human milk with lower acidity at the beginning of the introduction of enteral feeding, capable of decreasing the chances of disease occurrence. The high calcium intake and the increased chance of osteopenia constituted an unexpected result, which confirms the need for studies on mineral nutritional recommendation and supplementation. It is reiterated that attention must be reinforced in other risk situations, such as newborns conceived by single women, with compromised birth weight, who present infectious complications during hospital stay and undergo long periods of sedation and ventilatory support.


Long-wire very low frequency antennas, when lifted up on high altitudes by an aerostat, move through different atmospheric layers and interact with them electrically in a more intense way in comparison with aircraft flights. Such interactions manifest themselves in the form of electrical changes in the clouds and corona discharges excited on the antenna wire, which may increase the risk of mechanical damages and transmitter overload. In order to investigate the interactions between the different types of clouds and a long balloon-borne antenna wire, two theoretical models were developed and compared with results from an experimental balloon flight directly through a storm front. Based on the theoretical and experimental results, the most accurate model proposed was chosen, as well as a set of basic requirements for the balloon-borne VLF antenna system, reducing the risk of failure during operation in highly electrically active atmospheric environments. Very low radio frequencies  have been used since the 1920s for long-range stable telegraphic communication, transmission of time- and frequency standards, and communicating with submerged submarines and mines. Antenna systems required to efficiently emit signals in these frequency range are, for mechanical and maintenance reasons, often reduced to multiple tuned mast-antenna systems with capacitive overhead wire nets [Solutions to reduce the costs and resources needed to establish a fully operating VLF antenna system are either supporting the ground-anchored radiating structure (wire) by an aerostat  or creatBalloon-borne antenna systems move through the atmosphere with total velocities much lower than these of an airplane , consuming less energy, and allowing the use of vertical linear antennas, providing an effective mean to emit a vertically polarized signal that possesses superior characteristics when exciting the terrestrial (ground–ionosphere) waveguide ,8.Such systems, however, interact with the surrounding atmosphere differently than the horizontal aircraft-trailed wires, as the balloon-lifted vertical wires are not only subjected to different speeds of electric charge accumulation and loss, but also may act as a shunt between two differently charged regions of a cloud, the flight through which cannot be directly avoided . All of these phenomena lead to the potential occurrence of intense corona and electrical discharges, which could damage the antenna itself, its coupling elements, and the transmitter ; additioModern research ,13,14,15The Earth’s atmosphere remains rich in ions of different charges produced by various physical phenomena—UV radiation, natural radioactivity, ionization in electric fields, etc. ; the plaThe clouds, due to the processes of coagulation of water droplets which capture free-floating ions, experience a very low electrical resistance, lower than the air in good weather. The conductivity of the air increases with altitude, reaching the highest values in the ionosphere. The precipitation (rain) leaving the cloud possesses a positive charge shortly after exiting the cloud; later on, however, during the fall, the charge drops  due to electrostatic interactions between the individual droplets of different sizes and the surrounding air .Q0 (C) can be formulated as follows:lossτ (s), corresponds to the time after which the electric charge of a particle decreases three times in the cloudless air [H (m) and can be approximated for different altitude ranges by using the given formulas:Due to the significant difference in electrical resistances between the cloud and the air in good weather, the charged particle/object loses its electric charge much faster in the latter conditions. This process is exponential and accelerates with the increase of altitude; the general function of this decrease from the particle’s initial electric charge less air . This coIn the presence of high electric fields and/or large electric charges, the loss of electric charge of an object may manifest itself in the form of corona—short electrical discharges, not always accompanied by glowing ionization of the air, appearing rapidly with clear intervals. The electric field strength above which the corona appears—the corona initiation field strength—decreases exponentially with the altitude, following Paschen’s law describing the breakdown voltage/electric field strength as a function of air pressure ,19; accoFor the airplanes, the loss of electric charge acquired via friction with the water and ice particles, as well as by the electrostatic induction, is facilitated by the affixation of special dischargers, consisting of an externally insulated short cable with a bundle of thin wires at the end . The disA cloudless atmosphere experiences a natural electric field of approximately 1 V/cm on the ground’s surface, dropping exponentially to 0.2 V/cm above 2 km of altitude and below 0.03 V/cm above 9 km of altitude . This weImianitov et al.  presenteL of 140 m, width b of 15 mm, and thickness d of 0.1 mm, with one side covered with plastic-coated paper (L·d (m2), with the assumption that the physical phenomena responsible for the accumulation and loss of electric charge remain the same.The balloon-borne VLF antenna in this analysis—both theoretical and experimental —has the form of a tape-like flat aluminum wire having total length ed paper . The eleDuring the ascent phase, the balloon mission, with a long vertical antenna, travels through three basic types of regions—cloudless, electric field in proximity to the cloud, and electric field inside the cloud.loss, dependent on the altitude, as defined by Formula (1).The cloudless zone exhibits electric charge exponential loss with the time constant, τmax.Q (C) formulated as follows [0 ≈ 8.854 F/m is the electrical permittivity of vacuum, and E (V/m) is the external electric field intensity. This maximum value is reached exponentially in time, with the time constant derived from the experimentally defined charge accumulation rate, Cv :The zone with electric field in proximity to the cloud—with particle density lower than inside the cloud—exhibits both electric charge accumulation and loss, with the maximum electric charge,  follows :(6)Qmax.3 C/m3/s , and 104r, is defined between the wire and an imaginative second electrode in the cloud or surrounding air , and distance r is assumed at 1 m. In real conditions, the distance, r, is a variable dependent on the actual shape of the cloud and the position of the equipment in relation to the cloud’s electric charge concentrations (if assumed that they could be considered as the ‘2nd electrodes’). The exemplary experimental electric field strength data used in this comparison do not indicate any more information related to the geometry of the measuring equipment/environment , presenting the electric field strength values only. If the aforementioned assumption is maintained and a simulated  cloud shape is delivered, a distance, r, could be introduced as a defined non-unitary value; however, this would limit the usefulness of the calculations, as the considered clouds present a lack of repeatability in this geometric scale . Hence, the unitary value of the distance, r, was assumed.The definition of electric field strength at a given distance r (m) from the wire remains under an assumption that the distance, eriments ). The eleriments :(9)V=QmaIE (V/m), around the electrified wire in this region can be derived:By using this formula, the electric field intensity, IIE (V/m):The third zone—the inside of the cloud—can be characterized by an increased rate of electric charge accumulation and negligible charge loss; thus, Formula (8) is reformulated into the following :(12)QII(t (s), can be substituted with a ratio ZH/v, where H (m) is the altitude, and Zv (m/s) is the ascent rate of the balloon mission .The external electric field strength, E, can be taken directly from the experimental data shown in Additional elements of the electrification process of the balloon-borne wire are the electric charge acquisition during the takeoff procedure and the creation of potential difference during the freezing of remains of liquid water remaining on the system.As the wire antenna of the balloon mission is lifted up from the ground from a lying-down, already-deployed position, it remains in a rubbing contact with the partially conductive substrate (the airfield—humid grassy surface). As the antenna rises, a difference of electric potential appears as an effect of the separation of charges between the wire and the ground ; assuminIn the mid-1940s, the works of Workman and Reynolds, as well as Gunn and Dinger, showed that, during the freezing process of water, an increase of the electric potential can be observed ; this prThe ‘static electric field model’ approach mentioned in the title of this section means that it is assumed here that the balloon mission does not interfere with the electrical structure of the clouds, thus allowing the use of encountered external electric field strength, E, in Formulas (11) and (13) (as presented in 2) in different electrified regions, with E (V/m) defined as previously, and λ (S/m) as the conductivity of the given region.The basis for the definition of the possible influence of the slow-moving balloon mission with a long vertical antenna on the electric field in the cloud and its proximities is the assumption that, during the passage of the balloon mission, the cloud remains in a quasi-constant state, which can be described by the equation of cloud equilibrium :(14)EbelThe three electrified regions—below the cloud, inside the cloud, and above the cloud —physically do not exist as a discontinuous formation; that is, the passage from one zone to another is smooth and continuous. Therefore, if discretized for different adjacent altitudes, H, the equation takes the following form:H to a common i, E′ is introduced as the value of the electric field strength modified by the presence of the antenna wire, and the index A is introduced as the one describing a parameter related to the antenna wire itself. Thus, Formula (15) can be expanded as follows:r = 1 m (similarly to the assumption in the previous section). The modified electric field strength, E′, in the next (i + 1) step can be easily calculated from this formula; this value shall be then used in Formulas (11) and (13). The mode of employment of Formula (16) is recursive; that is, the antenna electric fields calculated from (11) and (13) become AE in the next calculation step , along with the respective iE value from the cloud  approach the current density reaches 100−14 S/m ), the cu−13 A/m2 .H; E) plotted in Zone I: charge loss in clear air—Formulas (1) and (2), charge accumulation during takeoff, resulting in initial rise of electric potential (expanded to two cases: +300 V and −300 V),Zone II: charge loss and accumulation in the proximity to the cloud—Formula (11),Zone III: charge accumulation in the cloud—Formula (13); for the Ns clouds, the additional short local increase of electric potential of +230 V due to freezing of possible water remains at the 0 °C isotherm,Zone IV: charge accumulation and loss above the cloud , approximated by Formula (11),Zone V: charge loss in clear air—Formulas (1) and (2)–(5)—depending on the upper borderline of the electric field occurrence.To simulate the gain and/or loss of electric field strength of a balloon-born vertical wire (dimensions given in Zv (ascent velocity) was defined as 3 m/s ; the parameters of the antenna wire are used as defined in L = 140 m). For comparative purposes, a calculation of results for two lengths of wires—10 and 500 m—was also carried out. The calculated electric field strengths were summed with the external electric field strength in order to correspond to the worst-case scenario, where the total electric field strength may appear high enough to induce discharges.The ‘dynamic’ cases were expanded by using Formula (16), as described above. In all cases, the E function. For all cases, the electric field strength drops rapidly after the exit from the zone with external electric field in proximity to the cloud—a result of the increased conductivity of the surrounding air. For the Ns clouds, an increase of the electric field strength can be seen after the exits from the cloud regions (above the upper cloud borderlines)—the effects of changing electric charge accumulation mechanisms. The ‘static’ model clearly shows the electric field strength increase due to freezing of the water residue at the 0 °C isotherm ’ plots shortly above 4000 m of altitude)—this mechanism is perceptible in the ‘dynamic’ model as short increases of the E’s derivatives, which moderately accelerate the electric field strength growth.It can clearly be seen that the maximum values of the electric field strengths for all cases are significantly higher for the ‘dynamic’ cases, where the external electric field in the cloud and in cloud proximities is influenced by a long electrically charged object of different conductivity—the cloud, to maintain its equilibrium according to general Formula (14), for a changing conductivity elevates the electric field strength in the region where the disturbance takes place, as in Formula (16). As the local differences in conductivities reach many degrees of magnitude , the local electric field strengths are expected to locally increase significantly to compensate for this, according to the assumed aforementioned mechanisms; hence, there are large differences in the E values between the models. For the Sc clouds, the ‘static’ model of electrification presents electric field strengths rarely exceeding 0.5 kV/m, while for the ‘dynamic’ charging model, the values may reach up to 30 kV/m for both Sc and Ns clouds—despite their significant differences in initial electric field strengths, as shown in Z, approximately five times higher than during the ascent . This type of cloud entry and the electrostatic interactions between the wire antenna and its surroundings were simulated and are shown in During the parachute-descent phase of the balloon mission—after the balloon explodes at maximum altitude or the payload is deliberately cut off the balloon at target altitude—the antenna, if designed properly, shall also move in a vertical position and enter the cloud with a velocity, vThe residual electric field strengths, remaining during the landing, differ between the cloud types and interaction models, but rarely exceed ±500 V/m. The five-times higher vertical velocity decreased the maximum electric field values reached in most cases in both models —this mechanism can be extrapolated for even higher, airplane-typical velocities, which would result in even lower differences between the total electric field strength and the external electric field strength—proving that the fast-moving aircraft is less prone to accumulating a large amount of electric charge in comparison with a slowly moving aerostat. For the Ns clouds, the cloud re-entry starts at the altitude, with higher conductivity than in the Sc cloud cases, thus preventing the electric field strength coming from the charging antenna to develop a significant difference between itself and the external electric field.The maximum values of the electric field strength reached on all the presented plots are significantly lower than the values of the corona breakdown electric field strengths, as mentioned in 100–800 m—Sc, ‘static’ model, ascend and re-entry phases,900–1300 m—Sc, ‘dynamic’ model, ascend phase,>200 m—Sc, ‘dynamic’ model, re-entry phase,4–7 km—Ns, ‘static’ model, ascend and re-entry phases,8–10 km—Ns, ‘dynamic’ model, ascend phase,0.1–2 km—Ns, ‘dynamic’ model, re-entry phase.Both presented electrification models show increased charge gain on the antenna wire, despite the included functions of charge loss and, for the descent phases, increased velocity—this remains consistent with the influence of the electrification processes that drive the evolution and maturing of the clouds on other objects that appear in their proximities or insides . The eleThe model that is considered most correctly describing the actual antenna wire electrification processes when passing through the clouds and their proximities is the ‘dynamic’ model, as it includes the expected  influence of the antenna on the cloud’s electrical structure as a sort of an artificial disturbance. The ‘static’ model was built on simpler formulas which rely directly on the electrification processes in the clouds and the atmosphere, yet do not include the functioning of the cloud as a uniform, self-equalizing system—this appears as a crucial assumption for modeling electrostatic interactions which do resemble those appearing in reality in maturing charged clouds.As both models did not possess an implemented breakdown/lightning-strike condition , the model that showed the highest possibility of the occurrence of breakdowns is also the dynamic one, as in this model, only the electric field strength derivatives inside the clouds appear sufficiently large to sustain the rapid electrification after a possible discharge—a widely reported property of a highly electrically active cloud , imperceThe dynamic model results may be compared to the experimental results, which concentrated on the monitoring of corona appearing on the balloon-borne wire antenna of the same dimensions as in the simulations, traveling directly through a warm storm front.The research stratospheric balloon flight with one of the objectives to monitor the electrical interactions with the surrounding atmosphere took off from the Przasnysz Airfield (code: EPPZ) in Poland on 12 June 2021. A Styrofoam-made main gondola (cube with 0.3 m–long edge), suspended under a parachute and a latex helium-filled balloon, supported a 140 m–long tape antenna (dimensions and composition the same as described in the previous sections) with an additional polyethylene tether along it to reduce the mechanical strains; an extra radiosonde on a 2 m–long plastic tether was affixed below it, and a digital voltage meter was connected to the wire in the middle of its length (the meter failed to operate and delivered no data). The mission was launched shortly after a warm storm front passed above the airfield, allowing it to directly cross the Nimbostratus, Altostratus, and Cirrostratus cloud layers—as shown in The balloon mission landed safely on a local field, with the antenna fully stretched, proving that it traveled during the re-entry phase in the desired vertical position—the aluminum tape-like wire was, however, broken in multiple places. The avionics of the gondola remained intact, and the audio files from the receiver’s recorder were successfully retrieved for analysis.Zv (m/s), obtained from the balloon system’s navigation system operating in the APRS network. The values of the Zv velocity of 3 m/s for the ascend cases and 15 m/s for the re-entry cases were taken directly from this data .The higher concentration of corona discharges is directly linked to the increase of the electric field intensity around the balloon-borne antenna above a certain threshold value; the electric field strength, in order to excite the discharges, has to elevate itself rapidly in time—this property is manifested by the previously described dynamic model of electrification. The low altitude of the storm cloud during the experimental flight does not correspond to the lower cloud borderlines from the exemplary cases of the Ns clouds from Sankt Petersburg, Kyiv, and Tashkent due to local/climatic differences. As a best altitude match, 3, giving the approximate discharge currents in amperes. With the average discharge time of 1 millisecond, the average electric charge transfer in coulombs can be defined by integrating in time domain the current impulses [10x, with x being the aforementioned values. Based on the previous assumption for currents’ definition , it caneference —an effecr = 1 m at which the calculations were performed . Multiple discharge peaks show that the corona threshold value for the electric field strength is reached more rapidly and more often—an effect of the intense electrifying processes and, as the antenna is fully immersed in the charging medium with no separation/insulation, physically lower values of the maximum distance, r, between the antenna wire and surrounding charged humid air concentrations.The dynamic model of balloon-borne antenna electrification in every considered cloud case has produced a single maximum peak of electric field strength . The experimental corona discharge plot shows multiple peaks instead of one, considering that the discharges occur at the maximum electric field strength—this difference is the effect of the exemplary value of The plotted electric field strengths for both models and all cloud cases depict the electric field strength reached around the antenna wire in the moment the wire passes through the cloud/space of certain properties; after the antenna moves up and forward, the electric field strength either drops down in time to its previous value or evolves with the conventional evolution processes with the cloud. It should be, therefore, theoretically possible to influence the formation and evolution of clouds (by affecting their electric fields) by inserting into them a slow-moving, highly conductive disturbance in the form of a long antenna wire. Based on the qualitative analysis of the corona discharge currents and total charge flows, it can be expected that, from the perspective of the cloud, the electrifying effects of the antenna wire on the cloud structure cannot be treated as negligible; in an extreme case, the cloud may try to maintain its equilibrium by ejecting a certain electric charge upward—an ephemeral effect often known as the TLE (Transient Luminous Event), which is observed naturally only above highly electrified clouds.The calculation of the discharge currents from the recorded corona peaks can be performed accurately if a Pearson coil is employed as a receiving end of the recording system. This type of coil is, however, unadapted for light stratospheric balloon missions because of its small dimensions and very high density—this, from the point of flight safety, automatically elevates the balloon mission class to heavy, which demands more elaborated navigation and in-flight control; moreover, the majority of the payload available is dedicated to the coil only.It has been reported that the corona discharges are excited on the entire length of the antenna wire . Each diThe corona discharges, however, can be concentrated around mechanical structures which provide high electric charge density—spikes, single wires, or wire bundles , with the differences between the model and the experiment indicated. The electrification models can be refined with more detailed formulas describing the electrification processes in various atmosphere layers for different antenna geometries. A set of basic requirements for the antenna system was defined in order to reduce the risk of transmitter overload and antenna damage due to ongoing corona. An open problem is the accurate theoretical modeling of the ‘2nd electrode’ for atmospheric electrification processes and discharges; an engineering task would be to create a sufficiently lightweight and safe method for the discharge current measurements onboard a stratospheric balloon mission that is not based on a too-dense and too-heavy Pearson coil.


The development of variotherm systems has helped to improve the quality of micro-injection molded products. Thin electric heaters have significant advantages in size, efficiency and installation convenience. However, the use of thin electric heaters has brought the problem of non-uniform temperature distribution of the insert. The good replication of the functional surfaces containing microstructures quickly and uniformly is still a challenge. In this work, the heating performance of the thin electric heater in a variotherm system is investigated by combining numerical simulations with experiments. Micro-injection molding of PP micropillars was also performed. The obtained results show that the addition of a transition layer with high thermal conductivity in the heating structure can optimize the uniformity of the temperature distribution of the insert. Furthermore, the replication heights of the micropillars can be significantly increased by the developed variotherm mold, which provides a new idea for the optimal design of a local variotherm system. Components containing microstructures have been widely used in biomedical , aerospaIn contrast to conventional injection molding, the rheological properties and thermodynamic behavior of polymers during the micro-injection molding process are usually influenced by scale effects . As a reIn conventional injection molding, a variotherm system based on rapid mold heating and cooling is often used to improve the surface quality of products. In micro-injection molding, the goal of the application of the variotherm system is to improve the quality of microstructures. The molding defects that may occur in conventional injection molding may not exist in micro-injection molding. However, bending, fracture, stretching, necking, surface burr and incomplete filling of microstructures become the main molding defects .The mold temperature and the cavity pressure have significant impacts on the molding quality of micro-injection molded products ,10. G. LWhen the cavity temperature increased from 60 to 100 °C, the average molding height of the microstructures increased from 0.37 to 1.14 μm. At the same time, the uneven distribution of the molding pressure was an important factor that led to different regions with different heights of microstructures . In addiA cavity temperature that is overly low will cause the premature formation of a frozen layer of the polymer melt ,14. In tTo shorten the molding cycle and improve the product quality, some scholars have used infrared heating ,17 or inWang and Zhao  from ShaConsidering the problems in these studies, an improved method of the variotherm system based on close heating is proposed in this work. We analyzed the factors affecting the temperature uniformity of the insert. A transition layer with high thermal conductivity is added between the close heating source and the insert to control the heat transfer path. The temperature distribution of the insert is optimized with a guaranteed heating rate. An injection mold for micro-pillars is designed and manufactured. The surface temperature distribution of the insert is measured and evaluated by simulations and experiments. Finally, the developed mold is used to fabricate PP products with micro-pillars, and the effectiveness of the improved method in optimizing the insert temperature distribution is verified.The Rapid Heat Cycle Mold (RHCM) developed in this study is based on wafer resistance heating and the water cooling on the insert block as shown in The thin electric heater used in this paper is also known as a thick film resistor. The thin electric heater was made of an insulating layer, resistance paste, protective glazes and other materials , heat capacity (C) and density (ρ) of the mold are shown in 2.Three heating modes with a thin electric heater were compared by simulation. The three modes were direct heating, the addition of a flat graphite transition layer and the addition of a graphite transition layer with a circular hole. The heating power of the thin electric heater was 120 W/cmTemperatures were obtained from the five positions of the insert. The sampling locations are shown in The results show that, when using a thin electric heater with a high temperature uniformity, the temperature distribution of the insert still exhibited significant non-uniformity. For an insert with a side length of 20 mm, the temperature difference between the center and the edge was 50–60 °C. The occurrence of this situation will have a negative impact on the overall molding quality of microstructures.The material of the transition layer was graphite, and the thermal conductivity was set to 150 W/m°C. The graphite layer was located between the heat source and the insert and had dimensions of 25 × 25 × 1 mm. 2 in the simulation model.In order to avoid the excessive heating in the center of the insert-containing microstructures, a hole structure was added to the center of the transition layer to avoid direct contact between the insert and the transition layer. The solid heat transfer process between them was isolated, and only a relatively small amount of air convection heat transfer took place to reduce the concentration of heat in the center. The convective heat transfer coefficient was set to 30 W/mThe simulation results in The standard deviation (SD) is introduced to evaluate the temperature distribution uniformity of the inserts. The standard deviations of the heating temperature for the three heating modes are compared, and the results are shown in When the distance between the heat source and the insert is close and the direct heating mode is used, the uniformity of the temperature distribution of the insert is the worst. By adding a transition layer with high thermal conductivity between the heat source and the insert, the uniformity of temperature distribution can be improved. At the same time, the uniformity of the temperature distribution of the insert can be further improved by machining a hole in the transition layer in the temperature concentration area of the insert.To further understand the effect of the circular hole size on the uniformity of the temperature distribution of the insert, the effects of transition layers with circular hole diameters of 4, 5, 6, 7 and 8 mm on the temperature distribution and uniformity of the insert are compared in When the average temperature of the insert reaches 373 K, the central peak value decreases significantly with increasing diameter of the insulated hole, and the proportion of the temperature uniform part of the center in insert increases considerably as shown in When a transition layer with an 8 mm circular hole is added, the heating time is 3.2 s. There is small time difference among these cases. However, when the radius changes to 10 mm, the heating time in the simulation analysis increases significantly to 4.5 s. This is because the actual contact area between the transition layer and the insert is significantly reduced due to the large diameter of the round hole, thereby, resulting in a slow temperature rise rate in the overall temperature of the insert. The size of the circular hole has a direct influence on the temperature distribution of the insert. In practice, the size and the number of circular holes should, therefore, be determined by the size and the shape of the insert.In addition, materials with different thermal conductivities for the transition layer with an 8 mm circular hole have been compared. Common materials with high thermal conductivity, such as graphite and copper, were mainly considered. The thermal conductivity of graphite was set to 150 W/(m°C), and that of copper was set to 380 W/(m°C). The standard deviation of the temperature of the insert with these two transition layers is compared in As the thermal conductivity of the transition layer material increases, the temperature of the insert is more uniformly distributed. As the heating time increases, the standard deviation of the temperature of the insert increases continuously in the absence of the transition layer. When the graphite transition layer is added, the standard deviation of the insert temperature is stabilized at 20–22.5.When the copper transition layer is used, the standard deviation of the insert temperature is stabilized at 12.5–15.0, which is an obvious improvement. At the same time, the heating time increases from 3.2 to 3.5 s when the thermal conductivity of the transition layer increases from 150 to 380 W/m°C. This is due to the fact that, when the thermal conductivity of the transition layer increases, the heat exchange between the transition layer and the contact part of the mold outside the insert also increases. Then, the heat energy obtained by the insert decreases, which leads to a longer heating time.The evolution of the insert temperature distribution during the RHCM micro-injection molding process was investigated to further demonstrate the feasibility of temperature optimization. Taking the micropillars as an example, the insert temperature measurement and micro-injection molding experiments were performed. The machine used in the experiments was an all-electric injection molding machine provided by Sodick Company .The molding material was PP (HD-120MO). To improve the filling quality of the micropillars, the average surface temperature of the insert was heated to 100 °C. The cooling stage should be below 50 °C to allow the parts to solidify completely and to avoid microstructure deformation caused by high temperature during the demolding. Using the developed mold  A thin electric heater with local heating can realize the rapid temperature change of the insert over a wide range, and the method of combining the thin electric heater with a transition layer is a good solution to improve the temperature uniformity of the insert.(2) The thermal conductivity of the transition layer and the size and number of holes have an important effect on the temperature distribution of the insert. The increase of the thermal conductivity of the transition layer and the diameter of the circular hole can effectively improve the temperature distribution uniformity of the insert.(3) In the experiment, the injection molding cycle of the micropillars could be controlled within 40 s. The thin electric heater not only improved the efficiency but also greatly increased the energy utilization. Temperature had a significant effect on the forming of microstructures. By adding a transition layer, the height of micropillars in the edge region of the insert was increased from 28.98–45.20 to 37.21–49.55 μm.(4) There was some difference between the height of the molded micropillar and the actual cavity depth of 60.2 μm. The cavity pressure would be the main reason for this difference. Regarding the molding quality of the micropillars in each area, microstructures should not be designed within 1–2 mm of the edges of the insert.In general, reasonable rapid thermal circulation is important and necessary for micro-injection molding. Adding a transition layer with a circular hole allows the heat transfer path of the heater to be controlled and the temperature field in the cavity to be optimized. Based on this method, the “Conformal Heating” technique can be further developed.


Australia's caesarean section (CS) rate has been steadily increasing for decades. In response to this, we co‐designed an evidence‐based, multi‐pronged strategy to increase the normal birth rate in Queensland and reduce the need for CS. We conducted three workshops with a multi‐stakeholder group to identify a broad range of options to reduce CS, prioritise these options, and achieve consensus on a final strategy. The strategy comprised of: universal access to midwifery continuity‐of‐care and choice of place of birth; multi‐disciplinary normal birth education; resources to facilitate informed decision‐making; respectful maternity care and positive workplace culture; and establishment of a Normal Birth Collaborative. Caesarean section (CS) can be lifesaving for mothers and babies. However, the global rise in CS is ‘unprecedented and unjustified’.2 body mass index.The rate of CS in the Australian state of Queensland is higher than the international average in Organisation for Economic Co‐operation and Development countries, but similar to the rest of Australia. In 2018, 35.2% of all women in Queensland had a CS .Queensland Clinical Guideline: Normal Birth,The analyse the drivers of CS in Queenslandfacilitate a multi‐stakeholder group to co‐design a coherent strategy to increase normal birthprioritise key activities, identify enablers and resisters, and rate the degree of complexity and difficulty of each activitydetermine who is needed to fully design, implement, and evaluate the key activities.Considering the high rates of CS in Queensland, including cumulative impact of repeat CS following primary CS, we undertook a project aiming to co‐design an evidence‐based, multi‐pronged strategy (the Strategy) to increase the normal birth rate in Queensland public hospitals. The project objectives were to:To innovate, design and create the Strategy we used a co‐design methodology to facilitate a collaborative iterative staged process, with multi‐disciplinary key stakeholders who have extensive experience in maternity care in Queensland.Key stakeholders from across Queensland Health were invited to participate in a series of three online workshops conducted between March and June 2021. Sixteen participants contributed to each 90‐min workshop. Participants included six obstetricians , one rural and remote medicine specialist, five midwives, two First Peoples midwives, and two consumer representatives. The workshops were video‐recorded, and a senior researcher took detailed notes. The notes were summarised, checked for accuracy, and performed content analysis analysed after each workshop to develop themes. Some participants emailed additional ideas and information that were collated and analysed. Findings from the previous workshop were presented for participants to consider in advance of the subsequent workshop. Prior to the final workshop, participants had an opportunity to review and provide feedback on the draft Strategy.redesign maternity careinstitutional enablersworkforce capability.Prior to the workshop, participants were emailed a desktop literature review of key drivers of CS in Queensland Box . These iBox 1ClinicalHigh rates of induction of labour and epidural analgesia, along with low rates of VBAC directly, or indirectly, drive CS.Political and policyQueensland Normal Birth Clinical Guideline is not well‐integrated with other policies and initiatives.There is no national policy or campaign to address overuse of CS. The EconomicActivity‐based funding provides a financial disincentive to reduce CS.Socio‐culturalMedical model and fear of birth undermines clinician and community confidence and devalues normal birth.TechnologicalMaternity services in Queensland have invested heavily in medical technologies which directly, or indirectly, drive CS rates without delivering clinical benefit.LegalFear of medico‐legal consequences for not performing CS lowers obstetric threshold which drives up rates of CS.EnvironmentalBirth suite environment increases risk of CS compared to birth centre and homebirth for women at low risk of complications.Box 21. Redesign maternity careRedesign midwifery careProvide universal access to a best‐practice model of midwifery continuity of careProvide access to Birthing on Country for First Peoples womenProvide community‐based midwifery antenatal and postnatal visitsRedesign obstetric careRemove routine obstetric appointments for women with normal pregnanciesProvide continuity of obstetrician / registrar for antenatal careProvide multi‐disciplinary obstetric visits close to when issue identifiedRedesign birth settingProvide publicly funded homebirth and access to homebirthIncrease access to birth centresUse birth unit design principles to facilitate normalisation in birth suite2. Institutional barriers and enablersRemove financial barriers to preventative, quality maternity careQueensland Health provide health services with bundled funding for each woman's pregnancy/birth/postpartum careFunding for one‐to‐one ratios for midwives caring for women in labour on birth suiteUse outcome data to drive behaviour changePublish costs and outcomes for each hospital and health services on Queensland Health website (publicly available)Use International Consortium for Health Outcomes Measurement or other standard set of outcome measures to report health outcomes and longer‐term outcomes Report variation in CS rates between clinicians, between public and private3. Workforce capabilityDevelop evidence‐informed Queensland Health guidelines that facilitate clinical judgement and women's choicesAudit clinicians' access to, and application of, clinical guidelinesDevelop procedures that embed guidelines in practiceIntegrate other policies with normal birth guideline to avoid ‘clashing’Facilitate women's informed decision‐making about interventionsEducate workforce about how to critique the evidence; and how to normalise, individualise, and counsel women about the risks and benefits of medical interventionsUse ‘real world, real time evidence’ to create risk predictive modelsEducate workforce to promote normal birth and address fearDeliver targeted, multi‐disciplinary education forums about the benefits of normal birth and how to facilitate itFacilitate dialogue between Health and Human Services lawyers and obstetricians to de‐escalate fears of malpractice litigationIdentify normal birth clinical leaders and champions who can expose clinicians and managers to normal birthEducate workforce and consumers to use a ‘speak up for safety’ process to advocate for normal birthBuild workforce capacity and team functionProvide clinical‐peer supervision model for midwivesProvide advocacy training to help midwives ‘keep birth normal’Provide a program  program) that enhances multi‐disciplinary team functioningRevise human resources practices that undermine sustainability of midwifery models in rural areas (eg one‐shift cannot be undertaken while on maternity leave)develop consensus on short, mid, or long‐term activities as part of the Strategyrate the degree of complexity of each activity – consider enabling and resisting factorsrate the degree of difficulty of each activity – consider enabling and resisting factorsconsider creating a collaborative as an implementation approach, andconsider/design elements of the full Strategy.Prior to the workshop, participants were emailed a survey link inviting them to prioritise activities (full list in Box Most participants responded to the priorities survey (76%). The survey results were presented and discussed at the workshop, to move toward consensus on activities to form part of the Strategy. Discussion included consideration of degree of complexity and difficulty of activities, and whether certain activities could be integrated or embedded into a larger system change.Prior to the workshop, participants were emailed the draft Strategy to review and formulate feedback at the final workshop. Workshop objectives were to revise and agree on the Strategy. Participants decided that the Strategy should focus more broadly on ‘normal birth’ as opposed to just on CS. Normal birth was defined as the normalisation of the physiological process that is birth, as opposed to being focused on a type of birth  or level of medical intervention. Participants discussed the development of a Normal Birth Collaborative as a vehicle to promote, embed and sustain the recommendations. Discussion included purpose and remit, membership, and initial priorities of the Collaborative.change culture to promote normal birth and mitigate fear of birthcentre women's informed decision‐making, access, and controlrespect the scope of practice of midwives, obstetricians, and other maternity care providersuse cost‐effective, evidence‐based solutions, andprivilege consumer voices in service design and delivery.Using these principles, we developed the Strategy to promote normal birth which has fiveopportunity to receive midwifery care from a known midwife during pregnancy, birth and the first 6 weeks afterward. This model of care includes obstetric consultation, collaboration and referral as indicated.Universal access to midwifery continuity of carer and choice of place of birth. Redesign maternity care so that every woman has the Multi‐disciplinary normal birth education: deliver multi‐disciplinary education for maternity staff that includes obstetricians, midwives, midwifery and medical students, and maternity consumers.Co‐designed resources for obstetricians and midwives to facilitate informed decision‐making: develop, implement, and evaluate a resource package to facilitate women's informed decision‐making in areas that directly, or indirectly, impact normal birth.Initiatives to embed respectful maternity care and positive workplace culture: facilitate midwives, obstetricians, and maternity leaders to deliver high‐value, quality maternity care.Establishment of a sustainable Normal Birth Collaborative: establish and sustain a multi‐disciplinary collaborative of maternity leaders, obstetricians, midwives, maternity consumers, and maternity researchers to drive the Strategy and champion normal birth throughout Queensland with a view to becoming a national leader with global influence.Each component bundles together several evidence‐based activities. The full details of each component will be published in the forthcoming full report.Participants agreed that the following principles should underpin development of the Strategy:This work was commissioned and funded by Clinical Excellence Queensland, Queensland Health.