Unskilled birth attendance is a major public health concern in Sub-Saharan Africa (SSA). Existing studies are hardly focused on the socio-demographic correlates and geospatial distribution of unskilled birth attendance in Chad (a country in SSA), although the country has consistently been identified as having one of the highest prevalence of maternal and neonatal deaths in the world. This study aimed to analyse the socio-demographic correlates and geospatial distribution of unskilled birth attendance in Chad.The study is based on the latest Demographic and Health Survey (DHS) data for Chad. A total of 10,745 women aged between 15 and 49 years were included in this study. A multilevel analysis based on logistic regression was conducted to estimate associations of respondents’ socio-demographic characteristics with unskilled birth attendance. Geographic Information System (GIS) mapping tools, including Getis-Ord Gi hotspot analysis tool and geographically weighted regression (GWR) tool, were used to explore areas in Chad with a high prevalence of unskilled birth attendance.The findings show that unskilled birth attendance was spatially clustered in four Chad departments: Mourtcha, Dar-Tama, Assoungha, and Kimiti, with educational level, occupation, birth desire, birth order, antenatal care, and community literacy identified as the spatial predictors of unskilled birth attendance. Higher educational attainment, higher wealth status, cohabitation, lowest birth order, access to media, not desiring more births, and higher antenatal care visits were associated with lower odds of unskilled birth attendance at the individual level. On the other hand, low community literacy level was associated with higher odds of unskilled birth attendance in Chad whereas the opposite was true for urban residency.Unskilled birth attendance is spatially clustered in some parts of Chad, and it is associated with various disadvantaged individual and community level factors. When developing interventions for unskilled birth attendance in Chad, concerned international bodies, the Chad government, maternal health advocates, and private stakeholders should consider targeting the high-risk local areas identified in this study.The online version contains supplementary material available at 10.1186/s12889-022-13972-6. Despite a substantial global decline in maternal mortality ratio  by 38% between 2000 and 2017, several countries in Sub-Saharan Africa (SSA) continue to record high maternal and neonatal deaths as well as significant burdens of preventable pregnancy-related complications .Utilisation of maternal health services from unskilled birth attendants, defined as “persons who assist a mother during childbirth and who initially acquired their skills by delivering babies themselves or through apprenticeship to other traditional birth attendants” , is knowThere is considerable evidence to suggest that most unskilled birth attendants lack the required knowledge and skills to manage complications associated with pregnancy or childbirth, such as haemorrhage, eclampsia, and obstructed labour . TherefoThe study was based on secondary data obtained from the Chad 2014–2015 demographic and health survey (DHS) conducted from October 2014 to April 2015. The survey included a nationally representative sample of 17,719 women aged 15–49 years selected from 17, 233 households. Respondent selection was based on a two-stage stratified cluster sampling procedure. For the first stage, 626 enumeration areas were selected from a list of clusters nationwide . HousehoThe outcome variable – unskilled birth attendance – was constructed from the categories used in the DHS concerning the person who assisted with the delivery of the respondent’s last child. In the DHS, the respondents were asked to identify the personnel that assisted them during delivery such as a doctor, nurse or midwife, community health officer or nurse, traditional birth attendant, traditional health volunteer, community or village health volunteer, relative, other, or no one. A binary outcome was constructed by categorising baby deliveries performed by traditional birth attendants, traditional health volunteers, community/village health volunteers, relatives, and others as unskilled birth attendance and the remaining health personnel as skilled birth attendance.The independent variables of the current study were mainly informed by findings of existing studies on unskilled birth attendance –14. The Community variables were computed at the primary sampling unit level. Community socioeconomic status was computed from occupation, wealth, and education of study participants who resided in each sampled cluster as all community variables are for only women. Principal component analyses were applied based on women who were unemployed, uneducated, or from poor households. A standardised rating was derived with an average rating (zero) and standard deviation . The ranRespondents who attended higher than secondary school were considered literate while all other respondents were given a sentence to read and were considered literate if they could read all or part of the sentence. Therefore, if respondents had higher than secondary education or had no school/primary/secondary education but could read a whole sentence, it was considered as high literacy. Medium literacy represented respondents who had no school/primary/secondary education and could read part of the sentence. Low literacy comprised respondents who had no school/primary/secondary education and could not read at all. Thus, socioeconomic status and literacy level were measured as low, moderate, and high at the primary sampling unit level (cluster) while place of residence was measured as urban or rural. The explanatory variables of the current study were mainly informed by findings of existing studies on unskilled birth attendance –14.Two levels of analysis were conducted. A descriptive analysis was performed by calculating the proportion of respondents’ socio-demographic characteristics. Multilevel logistic regression analysis was conducted to estimate associations of respondents’ socio-demographic characteristics with unskilled birth attendance. The Model 1 (null model) was estimated to establish whether there is a significant variance in unskilled birth attendance at the cluster level to justify the multilevel analysis, while Model 2 comprises the fixed effects analysis of individual-level socio-demographic factors and assumes that these socio-demographic factors have fixed or constant association with unskilled birth attendance across all the primary sampling units. Model 3 estimated the effects of the community-level variables and assumed that the effects may vary across the primary sampling units. Model 4 contains the full model  and the mainstay of the analysis. Adjusted odds ratios and 95% confidence intervals were calculated for the variables. All analyses were conducted with Stata software (Version 14) and the results were weighted to cater for potential over-sampling and under-sampling.Regarding the spatial analysis, the coordinates of the surveyed respondents were obtained from the DHS website. These data were projected to UTM Zone 33 N to aid the spatial analysis. Relying on just the surveyed point was insufficient, so Chad’s departments’ shapefile was obtained from the Humanitarian Data Exchange for the spatial analysis . The depAs part of the dependent variable’s data processing, birth attendance was coded 0 for skilled birth attendance and 1 for unskilled birth attendance. The independent variables were in their original categories, but proportions were generated from the lower categories at each sub-regional level. Therefore, the extracted surveyed data was linked with its corresponding coordinates. These data were then merged with the sub-regional shapefile using the join tool. In joining, the average computation system was adopted to estimate averages of unskilled birth attendance at the sub-regional level (departments). After obtaining the sub-regional level estimate of unskilled birth attendance, the independent variables’ proportions were added to asssist with the computation of the geographically weighted regression (GWR).2 (0.32). This revealed the best combination of independent variables that are significant predictors of unskilled birth attendance in Chad. This allowed the use of the identified independent variables that were used for the GWR. In conducting the GWR, the identified independent variables found to be significant predictors of unskilled birth attendance in Chad were used as the explanatory variables with kernel type being fixed as well as bandwidth method using the AICc. The obtained adjusted R2 was about 0.309 percent which implies that the results explain about 31% of the entire data. All the data processing and analyses were conducted in ArcGIS version 10.7.The actual data analysis began with using the spatial autocorrelation tool (Moran’s I) to assess the distribution of unskilled birth attendance in Chad. The spatial autocorrelation assesses the distribution of a phenomenon being studied; thus, either random, dispersed, or clustered. The output does not show the exact sub-regional distribution of unskilled birth attendance. Therefore, the Getis-Ord Gi hotspot analysis tool was used to examine areas that had a higher tendency of experiencing unskilled birth attendance. A limitation of the hotspot tool is that it considers areas with high values of the dependent variables to create hot and cold spots. However, it is advisable to use the Anselin Local Moran’s I cluster and outlier analysis tool for policy implications to explore other areas that may not be identified as a hotspot but have a high incidence of the phenomenon being studied. The final analysis was to determine the spatial explanation of the independent variables by running the GWR. GWR is a spatial regression technique that focuses on the spatial differentiation in the explanatory power of independent variables. This is done by estimating separate regression equations between the dependent and independent variables to every feature in the dataset. Before running the GWR, significant independent variables were identified using the exploratory regression analysis. This regression method was adopted because it assesses all possible combinations of the independent variables that best explain the dependent variable. Thus, it looks for models that meet all of the requirements and assumptions of the OLS method. The first model of the fifth category was accepted since it had the criteria  that contributed to the highest adjusted RThe Likelihood Ratio (LR) test was used to evaluate the fitness of all the models. Before fitting the models, the presence of multicollinearity between the independent variables was evaluated. The variance inflation factor (VIF) test found the absence of high multicollinearity between the variables (Mean VIF = 1.94).The prevalence of unskilled birth attendants was 61.5 percent. More than half of the women who gave birth had no formal education (65. 1%), were married (83.6%), desired birth (81.3%), had low socioeconomic status (65.2%), and were residents of rural areas (80%) while few had higher education (0.6%), never been in a marital union (1.2%), desired for birth later (14.5%) had moderate socioeconomic status (4.3%) and were residents of urban areas (19.8%) , poorest wealth status , no media access (70.2%), less than four antenatal visits (71.2%), low socioeconomic status (70.7%), and low literacy levels (79.0%) utilised the services of unskilled birth attendants during delivery  to utilise the services of unskilled birth attendants during delivery compared to those with no formal education. Those within the richest wealth status were less likely  to utilise the services of unskilled birth attendants during delivery compared to those with the poorest wealth status. The lesser likelihood was applicable for all wealth indices above the poorest wealth status. Women who were cohabiting were less likely  to utilise the services of unskilled birth attendants during delivery compared to those who were married. Women with access to media had a lesser likelihood  of utilising the services of unskilled birth attendants during delivery compared to those with no access to the media. The likelihood of utilising the services of unskilled birth attendants was lesser  among women who made 4 or more antenatal visits compared to women who made less than 4 visits  to utilise the services of unskilled birth attendants during delivery compared to those who then desired for birth. The likelihood of utilising the services of unskilled birth attendants was higher  among women who had 2–3 birth order compared to women who had 4 or more. Those with low community literacy levels were more likely  to utilise the services of unskilled birth attendants during delivery compared to those with high literacy levels. Likelihood of utilising the services of unskilled birth attendants was less  among women of urban residence compared to those of rural residence  . However, due to inter-cluster heterogeneity in the features, the total variance in deliveries aided by unskilled birth attendants decreased (32%). This suggests that disparities in delivery assisted by unskilled birth attendants are partly due to unaccounted community-level characteristics, as illustrated in Model 4.  demonstrated low variance in the likelihood of delivery assisted by unskilled birth attendants , the spatial distribution of unskilled birth attendance in Chad was clustered. This means that the spatial distribution of unskilled birth attendance in Chad was not randomised and can be found around a particular area. Therefore, the study used the Getis-Ord Gi hotspot analysis to visualise the distribution of unskilled birth attendance in Chad  or low/moderate level of literacy, and living in rural areas were associated with a higher likelihood of obtaining services from unskilled birth attendants. Our findings are consistent with a previous study that focused on skilled birth attendance in SSA  and alsoFindings from this study also demonstrate that between and within communities in Chad, there are significant wealth-related inequalities associated with seeking the services of unskilled birth attendants. The disparities between communities explained about 32% of the differences in seeking the services of unskilled birth attendants, suggesting that about 68% of the differences in seeking the services of unskilled birth attendants can be attributed to differences within the community. Similarly, earlier studies indicated that there are disparities in seeking services from skilled birth attendants in SSA countries, including Chad, where there are poorer socioeconomic conditions, such as limited access to health facilities and wealth , 17, 18.Studies found that socioeconomic conditions with geographic inequalities have significant effects on health outcomes and behaviours, such as seeking services of unskilled birth attendants in SSA countries including Chad , 12, 19.Despite the significant findings revealed in our study, some limitations need to be acknowledged. First, our study is cross-sectional and therefore we were unable to examine the temporal sequence of events to make causal inferences. Also, personal level measures of the women were self-reported, which is susceptible to recall and social desirability biases leading to either under or over-estimation of results. Additionally, we were unable to identify specific districts, towns, and villages in our geospatial analysis to determine the exact location of the women who may be at risk of seeking services from unskilled birth attendants.Considering that the DHS data did not capture the specific in-depth reasons why unskilled birth attendance is significantly associated with the identified variables in this study, qualitative approaches can be employed in exploring further meanings of these results. For instance, uneducated mothers with low wealth statuses in rural Chad can be interviewed to further understand their unmet needs regarding the utilisation of services from skilled birth attendants.Our study shows that more than half of the women in Chad (61.5%) utilised pregnancy and child-delivery services from unskilled birth attendants. We conclude that unskilled birth attendance was highly clustered in all parts of Chad except the southern part owing to various individual and community level factors. Specific individual-level factors associated with the likelihood of using services from unskilled birth attendants in Chad include lower educational level, lower wealth status, lack of adequate access to media messages, having no desire for more births, and lower antenatal care visits during pregnancy. Low community literacy levels and rural residency are significant community-level factors associated with higher odds of utilising services from unskilled birth attendants in Chad. These findings suggest that multiple individual and community-level interventions should be developed to address the high level of unskilled birth attendance in Chad. Improving maternal education and community literacy among women and supporting them to utilise the services of skilled birth attendants during antenatal care can be useful strategies in addressing the problem of unskilled birth attendance in the country.Additional file 1. Moran’s I SpatialAutocorrelation of unskilled birth attendance in Chad.


There have been widely documented beneficial role of vaginal Lactobacillus species as an important biomarker for vaginal health and healthy pregnancy progression. When translating this to clinical settings, pregnant women with low proportions of Lactobacillus and commensurately high proportion of rich and highly diverse abnormal microbiota are most likely to encounter negative pregnancy outcome such as preterm birth and postpartum complications. However, multiple literatures have also addressed this notion that the absence of a Lactobacillus-dominated microbiota does not appear to directly imply to a diseased condition and may not be a major determinant of negative obstetric outcome. Caesarian delivery is notably a risk factor for preterm birth and postpartum endometritis, yet recent data shows a trend in the overuse of CS across several populations. Growing evidence suggest the potential role of vaginal/uterine cleaning practice during CS procedures in influencing postpartum infections, however there is a controversy that this practice is associated with increased rates of postpartum endometritis. The preponderance of bacterial vaginosis associated bacteria vagitype at postpartum which persist for a long period of time even after lochia regression in some women may suggest why short interpregnancy interval may pose a potential risk for preterm birth, especially multigravidas. While specifically linking a community of microbes in the female reproductive tract or an exact causative infectious agent to preterm birth and postpartum pathologies remains elusive, clinical attention should also be drawn to the potential contribution of other factors such as short interpregnancy interval, birth mode, birth practices and the postpartum vaginal microbiome in preterm birth which is explicitly described in this narrative review. Lactobacillus-dominated vaginal profile are considered optimal for healthy pregnancy outcomes whereas an increased diversity and richness of vaginal microbial community with high proportions of non-Lactobacillus dominated microbiota including several bacteria vaginosis associated bacteria (BVAB) are considered unhealthy and a potential risk factor for preterm birth (Lactobacillus vagitype may not be requisite for adverse pregnancy outcomes (The objective of the Human Microbiome Project (HMP) is to provide a detailed characterization of the structure and composition of the microbiome across various body habitats . About arm birth , postparrm birth  and pretrm birth , 9. Hithrm birth –14 and prm birth . Other soutcomes , 17. Theoutcomes . Aside toutcomes . Short ioutcomes . All theLiterature search was conducted in PubMed, Web of Science, Embase and Cochrane Library using multiple keywords both alone as well as in combination so that all factors that have received recent scientific attention is included. Birth mode, postpartum, vaginal microbiome, postpartum infections, preterm birth, vaginal cleaning, caesarian delivery, vaginal delivery, uterine cleaning, postpartum endometritis were important key words used. Peer-reviewed, English-language original study articles published in key papers addressing whether a given factor plausibly contributes to PTB were included. When selecting articles addressing vaginal preparation pre-CS, articles on WHO recommendations, randomized control trials and other articles supported by Cochrane review were included. Articles addressing similar factors contributing to preterm birth were excluded by focusing on more recent articles, web-based material were also excluded except from scientifically trustworthy sources . All results were uploaded to EndNote for the literature selection. The reference lists of eligible articles were also screened to detect relevant articles that were not identified by the initial search strategy. As illustrated, in utero microbial colonization of fetus has been suggested to play a substantial role in the early establishment of the infant's microbiome , defined by the World Health Organization (WHO) as the delivery of an infant before completed 37 weeks of gestation. PTB represents one of the major challenges facing obstetrics and a leading cause of neonatal mortality worldwide . Annuallcrobiome , 33. Concrobiome . This recrobiome  which ad at term . L. crisgression , yet a J preterm . This inLactobacillus spp. or women lacking a vaginal Lactobacillus profile had 3-fold increased odds of being born via C-section, indicating that C-section is associated with vaginal dysbiosis in adulthood  or immediately after delivery especially for women with history of PPE.Infections at postpartum presents a significant burden to the hospital system and remains a significant cause of maternal mortality and morbidity worldwide , 40, yetalyticum  Clostridordellii , Clostrisyndrome  and Leptmetritis . DNA seqmetritis –60. Thesregnancy –60. Althregnancy , 54 and regnancy , thus eacrobiome . GardnerStreptococcus   , 83. Thees (HIC) , 84–86. es (HIC)  which rees (HIC) . In settes (HIC)  before oes (HIC) . Additioes (HIC) , therefoLactobacillus sp. dominance of the vaginal microbiome during pregnancy is dynamically altered during the postpartum period to a vaginal microbiome depleted of Lactobacillus spp. and enriched with bacterial vaginosis associated species. This dynamism provides evidence that oestrogen is likely an important factor in shaping the composition of the vaginal microbiome, particularly during pregnancy  was associated with only single birth per lifetime (primigravidas) compared to multigravidas with other lactobacillus spp or bacterial vaginosis associated vagitype that potentially increases the risk of premature delivery  during CS to postpartum endometritis. Recently, chlorhexidine and povidone- iodine are recommended vaginal cleansing antiseptics as they have minimal side effects, with low rates of allergies or irritation symptoms . Given t


High fluctuation with an absolute sum of all SU changes during the first 9 months was related to flares over 3-month periods , and high fluctuation during the first 3 months was related to flares in months 3–6 (p = 0.04). Monthly and high SU changes or again reaching higher SU levels > 360 µmol/l were not related to flares. Fluctuation and change in SU were related to flare occurrence during the first year of ULT, while changes between visits and reaching SU levels > 360 µmol/L were not related to flares.A gout attack may evolve after a purine-rich diet or alcohol and after starting urate-lowering therapy (ULT). The relationships between fluctuation and change in serum urate (SU) with the occurrence of flares were investigated in this study. In the prospective NOR-Gout study, gout patients with increased SU and a recent flare were treated to target with ULT over 1 year, with follow-up at year 2 with SU and flare as outcomes. SU and flares were assessed at both monthly and 3-monthly intervals until target SU was reached. Fluctuation over periods and changes in SU between two time points were assessed and compared in patients with and without flares. At year 1, 186 patients completed follow-up (88.2%) and 173 (82.0%) at year 2. Mean age (SD) at baseline was 56.4 (13.7) years, disease duration was 7.8 (7.6) years, and 95.3% were men. The first-year SU fluctuation and change were related to flare occurrence during year 1 (both  In gout, a prevalent inflammatory joint disease –3, hyperA gout attack may evolve after a purine-rich diet or alcohol, triggered by a proinflammatory effect of temporary increased serum urate . Flares NOR-Gout (Gout in Norway) is a prospective, observational single-centre study in a hospital-based rheumatology centre where patients satisfying ACR/EULAR classification criteria  and withAfter a baseline rheumatology outpatient visit at Diakonhjemmet Hospital, ULT was started with allopurinol 100 mg daily with 100 mg increments monthly until treatment target SU < 360 μmol/L  was reached, with the maintenance of this dose. Patients switched to febuxostat in case of intolerance or lack of efficacy. Compliance with medication was not specifically tested. Flare prophylaxis was at the discretion of the treating rheumatologist and included colchicine 0.5–1 mg daily for 3–6 months  in all bStudy visits assessed SU and flare status  after 1 The primary outcomes were SU and flares after the first year. At every clinical visit, the patient self-reported gout flares since the last visit during a structured interview with a trained study nurse who recorded the flares. If in doubt, the patient and the study nurse discussed whether an experienced episode with pain or swelling was to be defined as a gout flare or not. At all visits, laboratory examinations included SU (µmol/L).Fluctuation was used as a concept for accumulated positive and negative changes in SU, and was defined as the absolute sum of all observed SU changes between adjacent visits accumulated from baseline to time of observation, i.e. when flare occurrence was studied. SU change was defined as the difference between two visits, between 3-month time points or between years 1 and 2. SU fluctuation and change were compared in patients with and without flares during defined periods.We also studied the effect of larger SU changes between two visits with thresholds > 30 µmol/L, > 60 µmol/L and > 90 µmol/L for flare occurrence. Finally, we investigated flares among patients who, during the study, had reached the treatment target of < 360 µmol/L. We compared whether a consecutive SU increase to levels > 360 µmol/L and > 400 µmol/L, where an increased risk of MSU crystal formation is anticipated, was associated with flares.2 test or Fisher’s exact. Adjustments for multiple comparisons were not done. P < 0.05 was defined as statistically significant. Calculations were performed with IBM SPSS statistics (version 27).Descriptive measures for baseline demographics, SU levels and changes during the study and frequency of flares were explored with means with differences between groups using independent samples T-test and by the χPatient numbers Fig.  at visitMean SU decreased during ULT from 500 (SD 77) to 311 (SD 49) µmol/L in year 1 and 325 (SD 70) µmol/L in year 2. For fluctuation, the mean sum of SU changes from baseline was 196 µmol/L (until 3 months), 274 µmol/L (6 months), 307 µmol/L (9 months), 366 µmol/L (12 months) and 412 µmol/L (until 24 months). A flare during the study was experienced by 80.6% (150/187) during year 1 and 26.0% (45/173) during year 2.p = 0.019) was higher in patients with vs. patients without a flare , months 3–6 (p = 0.028) and months 6–9 (p = 0.029). Furthermore, fluctuation until month 3 related to subsequent flare during months 3–6 (p = 0.038).SU fluctuation during the increasing observation period is related to flare occurrence in 3-month periods. Table p = 0.025)  versus flare in 86.5% (122/141) among those without increased SU, p = 0.23 increase.Over 2 years time, no difference in flare was seen in those patients who, after being at target, again increased SU levels to > 360 mol/L or not, with a flare seen in 86.3% (88/102) among those with increased SU vs. 82.9% (68/82) in those without increased SU, This study shows that fluctuation and change in SU are related to the occurrence of disease flare. Fluctuation  was higher in patients with flares during year 1, but this was not observed for year 2. No relation to flares was seen for SU changes between adjacent visits, and not whether patients after initially reaching the treatment target again increased SU towards levels with increased risk of MSU crystal formation.We found thus that the sum of absolute SU changes over an observation period was a useful indicator of fluctuation, being associated with the occurrence of flare during year 1. High fluctuation up to the 9-month visit was related to flares over 3-month periods, and fluctuation during months 0–3 was related to subsequent flares in months 3–6, thus indicating future flares.Importantly, our study was performed in a clinical gout setting with intensive ULT, where SU was greatly reduced mainly in the first 3–4 months . At bestWe studied a large patient cohort with frequent assessments of both SU and flares which allowed us to study their relationship. We acknowledge limitations in our study due to a one-centre design, lack of a control group excluding causal inferences, and that the study was performed in an intensive ULT setting with predominantly SU reductions. The study design did not allow for capturing rapid daily changes in serum urate due to diet or other factors.In conclusion, we found that fluctuation in SU during 3-month periods and over the first year after the start with ULT was related to flares and even to subsequent flares in the first months. The sum of changes in SU was a useful way to measure fluctuation. To avoid fluctuations with possible flares, compliance with ULT treatment is important and colchicine prophylaxis over at least 6 months as recommended. Our findings require confirmation in other longitudinal studies. Findings support existing treatment recommendations with a focus on the gradual increase of ULT to lower SU , 5 and r


The alignment of cellulose by an electric field is an interesting subject for cellulose material processing and its applications. This paper reports an atomistic molecular dynamics simulation of the crystalline cellulose nanofiber (CNF) model in varying electric field directions and strengths. GROMACS software was used to study crystalline cellulose 1β consisting of 18 chains in an aqueous environment at room temperature, and an electric field was applied along the cellulose chain direction and the perpendicular direction with varying field strength. The root-mean-square displacement, radius of gyration, end-to-end length, and hydrogen bond population of the crystalline CNF model were analyzed to determine the effects of the applied electric field on the structure of the CNF model. The results suggest that the nanosecond electric field can induce the orientation of the CNF along the applied electric field direction. The alignment rate and ability to maintain the alignment depend on the electric field strength. Analysis of the radius of gyration, end-to-end length, and bond lengths for intrachain and interchain hydrogen bonds revealed no significant effect on the cellulose structure. Cellulose alignment in an electric field has the potential to broaden the design of electric field-induced processing techniques for cellulose filaments, thin films, and electro-active cellulose composites. Cellulose, the most abundant biopolymer produced in nature, has tremendous potential in many applications, including pulp, paper, additives, coatings, films, laminates, pharmaceuticals, foods, textiles, and composites ,2. Nano-The potential of nanocellulose is being utilized for structural composites, multifunctional composites, soft actuators, disposable sensors, biomedical devices, antimicrobial films, food packaging, separation/barrier membranes, and many more emerging applications ,4,5,6. CSeveral experimental works have been reported that demonstrated the effects of electric fields in the alignment of nanocellulose ,10,11. TCNC alignment in water under an AC electric field was reported, and increasing the electric field voltages by more than 2 kV/cm in a frequency range of 1 kHz to 2 MHz enhanced the alignment . The aliNanofibrillated cellulose was aligned in silicon oil . A permaRecently, improved piezoelectric properties of ultrathin CNF films were made by corona poling . HoweverIn this work, atomistic molecular dynamics simulations were performed to study the alignment effect of crystalline CNF under various electric field strengths and the corresponding effects on its structure. The CNF model used in these simulations is crystalline cellulose 1β consisting of 18 chains in an aqueous environment and room temperature, and the GROMACS 2019 software was used for the MD simulation. The objective of this study is primarily to investigate the induced alignment of CNF along the direction of the applied electric fields. The changes in the physical, structural, and dynamic properties of the crystalline CNF model are inspected under the applied electric fields.The atomic-scale MD simulations were conducted using a GPU-accelerated open-source Groningen Machine for Chemical Simulations (GROMACS) software  with All-Atom Optimized Potentials for Liquid Simulations (OPLS-AA) force field extended to parametrize cellulose molecules ,22,23. Tβ was used to build the simulation model [x, y, and z box vectors of 19.842, 19.842, and 26.832 nm respectively, and an image distance, d of 8.0 large enough to allow the anticipated alignment, and 1,032,660 TIP3P water molecules were added for solvation.X-ray diffraction measurements and unit cell specification of crystalline cellulose 1on model . Celluloon model , which won model . PeriodiThe initial structures were first energy minimized using the steepest descent protocol for 100,000 steps to eliminate unfavorable clashes between atoms followed by two 0.5 ns equilibrations. The first equilibration was conducted for 0.5 ns in the constant temperature and constant volume (NVT) ensemble, followed by the second equilibration step for 0.5 ns in the constant temperature and constant pressure (NPT) ensemble. The energy minimization employed a maximum force value of 1000 kJ/nm/mol converging criterion.The production MD was performed on the equilibrated starting structure in the NPT ensemble under 300 K temperature using the energy minimized cellulose coordinates as input. The velocity-rescale thermostat (relaxation time constant 0.1 ps) and the Parrinello-Rahman (relaxation time constant 1 ps)  with a gShort-range electrostatic interactions were cut off at 1.2 nm, and the long-range electrostatic interactions were calculated using the Particle Mesh Ewald algorithm . All bonThe simulation was conducted in external oscillating electric fields acting on every atom in the system with varying electric field intensities from 0.001 mV/nm up to 0.2 mV/nm. This electric field intensity range was found from the real field strength: 1 V/mm to 200 V/mm. The electric field frequency for the MD simulation of the CNF model cannot be the same as the experimental frequency values since the simulation model size is in the nm range, and the simulation time should not be hours.Thus, the electric field frequency and simulation time should be determined for the molecular level CNF model. In other words, in experimental electric field alignment, 1 kHz was chosen, which corresponds to the speed of electric field propagation is 10 m/s (=frequency × length = 1000 Hz × 0.001 m). Thus, the speed of electric field propagation should be the same as in the CNF model, and the frequency is 10 GHz (=10 m/s/1 nm). The maximum simulation time was chosen for 20 ns to emulate a static electric field.The two simulation cases based on electric field application are shown in ot and t along the trajectory was analyzed to predict the arithmetical values of the deviations in the structure under different external electric fields. The radius of gyration, end-to-end length, and hydrogen bond disparity were evaluated using GROMACS software [Analysis of the trajectories was conducted in addition to vis-à-vis zero-electric field conditions. The root-mean-square displacement (RMSD) of the cellulose structures at the time software .Visual Molecular Dynamics (VMD) software   and PyMOIn CASE 2, the CNF model cross-section was tilted at 45° from the x-axis, and an electric field was applied to the cross-sectional direction (x-axis). The simulation results clearly show the cellulose chains’ visible alignment parallel to the applied electric field direction. The alignment is induced at several picoseconds into the simulation, depending on the strength of the applied electric field. The degree of alignment regarding how quickly the alignment begins and how long full alignment is maintained depends on the applied electric field strength. In addition, it is important to examine if the alignment is lost later in the simulation.The ability at which the cellulose structure could resist the applied force before induced alignment along the axis of the electric field reduced as the electric field intensity increased. A low electric field intensity of 0.005 mV/nm was observed to be sufficient to induce alignment of the cellulose parallel to the axis of the applied electric field. At this electric field, an alignment was induced after 1.35 ns in the simulation, with complete alignment achieved after 0.2 ns and maintained for only 0.5 ns. This suggests that low electric field intensity is insufficient to maintain the achieved alignment; hence, the CNF model reverts to its original orientation.Increasing the electric field shows early onset of induced alignment of the CNF model and a significant increase in the time maintained the achieved alignment. At 0.06 mV/nm, the cellulose structure is observed to resist the electric field applied and maintains its initial orientation for 0.6 ns before alignment parallel to the axis of the applied electric field begins. This electric field is sufficient to maintain the achieved alignment throughout the simulation time up to 8 ns. This alignment result is similar to experimental results . IncreasThis indicates that the corresponding force subjected to the CNF model is strong where induced rotations are dominant, thus, eliminating any possibility of alignment. Both the onset of alignment and the relative time the cellulose stayed aligned as a function of time for all the applied electric field strengths were analyzed as shown in The simulations were conducted twice to verify the reproducibility of these results. The onset of alignment, time taken to complete alignment, and the alignment-maintained time are similar. The simulations were extended further up to 28 ns (~three-times longer) to determine if the CNF recovered its lost alignment after 8 ns. Although mild rotations of the CNF were observed, no alignment was regained after being lost. These findings suggest that CNF can be aligned in the low electric field as recently reported .Many studies have used electric field simulations in GROMACS using field frequency in the GHz range ,33. The A static electric field for electric poling is normally applied for more than 1 h to align CNF . Within The behavior of the CNF’s overall dipole moment is important in indicating the associated alignment of the CNF due to the applied electric field. Many molecules possess an electric dipole moment that orients itself in the applied electric field direction. This study applies the electric field along the z-axis for CASE 1. The z-component of the dipole moment increased steeply up to three-fold at higher electric field strengths reaching a plateau within the first 1 ns of the simulation and remaining constant throughout the rest of the simulation time. Due to the anisotropy of the CNF structure, its length axis is oriented in the electric field direction. A dipole moment of 214 Debye was noted for the optimized initial CNF structure. As shown in Therefore, the characteristic of the y-component of the dipole moment was investigated as shown in Additionally, a change in the y-component of the dipole moment is seen when the alignment is lost. This observation of the y-component of the dipole moment correlates with However, towards the end of the simulation, a change in the x-component of the dipole was observed, similar to the mild twisting of the CNF reported in While the results indicate induced CNF alignment at a low electric field, it is fundamental to understand the effect of the applied electric field on the cellulose structure. The CNF’s RMSD, the radius of gyration, end-to-end length, and hydrogen bond population were characterized. The analysis results indicate that all the electric field strengths, including the highest (0.2 mV/nm), have no discernible effect on the cellulose structure. RMSD quantitatively predicts the conformational stability of a simulation structure throughout the simulation. The deviation imposed by external stresses is calculated by comparing the simulated structure during simulation with the reference. RMSD is defined by Equation (1) .(1)RMSDfinalr(i) and initialr(i) are the coordinates of an atom i in its final and the initial structure, respectively, and N is the number of atoms in the structure.Here, Rg) quantifies the changes in shape and size of the simulation structure under external stresses  during the MD simulations. Rg is the distribution of the atoms in space relative to their center of mass and can be defined using Equation (2) [The radius of gyration (tion (2) .(2)Rg=1r(i) is the coordinates of an atom i, centerr is the center of mass coordinates and N is the number of atoms in the structure.Here, Rg: 3.178 nm). Variations in the end-to-end distance of the cellulose structure were evaluated by determining the distance between the first atom and the last atom in the index group of the cellulose model [Rg and end-to-end length observations as shown in se model . Table Sr ≤ HBr = 0.35 nm and donor-acceptor angle, α ≤ HBα = 30°.The hydrogen bond network in crystalline cellulose 1β plays a significant role in stabilizing the cellulose structure. A comprehensive analysis of the hydrogen bonds for all applied electric fields was conducted and compared to a zero-field simulation to better understand the effects of the electric field in the cellulose structure. The intrachain (O3H3…..O5 and O2H2…..O6’) and the interchain (O6H6…..O3 and O6H6…..O2) hydrogen bonds for all the applied electric fields were characterized. The overall intersheet hydrogen bond population was also calculated. In this study, the existence of hydrogen bonds is analyzed based on two geometric criteria: the donor-acceptor distance, The cellulose hydrogen-bonding networks within the cellulose structure were not significantly affected by the applied low electric fields. A closer look at the hydrogen bonds evolution trends reveals that within the first nanosecond into the simulation, the number of intrachain O3H3…..O5 a, intracThe repeated simulation for an extended time yields similar results for the intrachain, interchain, and overall hydrogen bonds as shown in As a result, the evolution of intersheet hydrogen bonds with the O6H6…..O2 donor-acceptor atoms was investigated. The results revealed a gradual increase of hydrogen bonds within the first nanosecond from 154 to an average of 295 for all applied electric fields as shown in Analyzing distance distributions of these hydrogen bonds  shows thBased on the criteria used in the analysis, the hydrogen bond distance distributions for intersheet hydrogen bonds  indicateThis study focused on the effect on CNF if an electric field is applied in the x-direction, cutting across the thickness direction of the cellulose structure as shown in When an electric field is applied, the CNF chains are supposed to be aligned parallel to the electric field. However, due to relatively solid cellulose chain networks, cellulose chains cannot be aligned along the film thickness direction. Yet, OH groups are still sensitive to the electric field, which results in the rotation of the cellulose chains in the out-of-plane direction such that more OH groups appear on the outside of the structure . The resFirst, a gradual clockwise rotation of the CNF from its initial orientation (45°) to align with the Cartesian x-axis due to the rotation of CNF chains in the out-of-plane direction was observed. Second, once the CNF is oriented in the Cartesian x-axis, expectedly, a slow rotation of the CNF follows to align its principal axis (z-axis) parallel to the direction of the applied electric field (x-axis). The primary goal of this simulation (CASE 2) is to observe the alignment of CNF, as has been reported in the literature, when an electric field is applied across the CNF’s thickness direction. Therefore, in this case, the scope of analysis was limited to the first part of the observed orientation as shown in The angle of orientation (tilt) of the CNF cross-section about the original Cartesian x-axis was used to estimate the alignment induced by the applied electric field in this case. The CNF model’s front and middle cross-sections were used in the calculation to ascertain behavioral correlation throughout the model’s length. The front cross-section and the middle cross-section of the CNF model at each nanosecond were analyzed to deduce the alignment by measuring the degree to which the cellulose x-axis orients about the x-axis as shown in The cellulose alignment and field strength dependence are readily seen. Upon applying the electric field for 1 mV/nm, cellulose’s x-axis remained stable at the initial orientation (45°) for approximately 2 ns before gradually rotating clockwise to align with the Cartesian x-axis. However, this electric field strength was insufficient to align the cellulose’s x-axis completely and could only achieve a degree of orientation of approximately 13° about the Cartesian x-axis at 6 ns as shown in This was followed by a slow rotation of the CNF model to parallel its principal axis to the applied electric field. A two-fold increase of the applied electric field strength to 2 mV/nm, as shown in This observation coincides with the experimental result . IncreasThis could be due to the corresponding resistance of the CNF model to the high external force imposed by the applied electric field. Similarly to 1 mV/nm, after the CNF model rotated out-of-plane to align its x-axis to the Cartesian x-axis, a slow rotation to align the CNF model’s principal axis parallel to the applied electric field (x-axis) followed.As shown in At 2 and 4.5 mV/nm, a characteristic jump in the orientation angle is observed before orientation begins. The dipole moment magnitude (x-component) increases as the electric field intensity increases. As shown in These results of the x-component of the dipole moment a correspInterestingly, when exposed to an electric field along the thickness direction, the OH groups of cellulose tend to align in the out-plane direction . As prevIt is reasonable to say that this phenomenon can be useful in tuning the surface properties of cellulose, such as the water contact angle, using an electric field. After the CNF was oriented in the Cartesian x-axis, the second part of orientation began where the CNF rotated to align its principal axis parallel to the applied EF. This second orientation phenomenon is evident in The CNF’s chain length was oriented on the z-axis, while the electric field was applied across the x-axis. During the gradual rotation of the CNF from the initial angle of orientation (45°) to the Cartesian x-axis, the z-component of the dipole moment b shows nThe y-component of the dipole moment b exhibitAs in the previous case, the stability of the cellulose structure in the high electric fields applied for this case was investigated by evaluating the RMSD, the radius of gyration, the end-to-end length, and the overall evolution of hydrogen bonds as summarized in The RMSD value remained stable but increased to 0.1124 from 0.1039 nm (no field) when an external electric field of 1 mV/nm was applied across the x-axis. The RMSD value increased to 0.1280 nm with the increasing electric field at 4.5 mV/nm. The deviation in the RMSD value remained small, below 0.13 nm, which indicates that the high electric fields used in this case are not high enough to change the cellulose structure. This could be attributed to the rotation of the cellulose structure as reported in Applying high electric fields across the x-axis showed that the cellulose cross-section hydrogen bonds align along the applied electric field. The radius of gyration did not show any deviation and remained at 3.178 nm for all the applied field strengths . EvaluatIn The alignment of the crystalline cellulose nanofiber model under external electric fields was investigated in this study as well as the subsequent effects on structural stability. The CNF model was crystalline cellulose 1β consisting of 18 chains in an aqueous environment and room temperature, and GROMACS software was used for the MD simulation. The induced alignment of CNF along the direction of the applied electric fields was investigated, and the changes in the physical, structural, and dynamic properties of the crystalline CNF model were inspected under the applied electric fields. The electric field was applied along the CNF length and the transverse directions. The RMSD, radius of gyration, end-to-end length, and overall hydrogen bonds were investigated to examine the structural denaturing due to the electric field.Under low electric fields, cellulose chains can reorient and align in the direction of the applied electric field with no effect on the cellulose structure. The low electric fields can maintain the achieved alignment. The present model and study revealed that cellulose alignment could be achieved by applying electric fields without denaturing its inherent structural properties. The insights gained through this study are useful in exploring the design of electric-field-induced processing techniques for cellulose filaments, thin films, and electro-active cellulose composites.


This paper links localised annual average ambient air pollution data to a population database of births in Northern Ireland between 2011 and 2017 to investigate the relationship between particulate matter (PM) 2.5 exposure during pregnancy and a range of birth outcomes, with a focus on birth weight.Linear regression analysis is used to estimate the effect of exposure to PM 2.5 during pregnancy on commonly studied markers of infant health , less commonly studied markers such as Apgar scores, and markers of placental health which potentially represent a mechanism through which pollution might negatively affect newborns. In addition to maternal characteristics and weather conditions, detailed adjustment is made for area of residence. Moreover, comparisons of birth outcomes are drawn amongst siblings born at different times and subject to different levels of in utero exposure, permitting adjustment for mother-specific factors common to siblings.Most birth outcomes exhibit a strong unadjusted association with PM 2.5 exposure that conforms with expectations. For birth weight, the negative effect of PM 2.5 weakens slightly after adjusting for differences in maternal characteristics and weather, but weakens much further after adjusting additionally for area of residence. After adjustment, being born to mothers in the middling (6-10 micrograms per cubic metre) and highest (10-16 micrograms per cubic metre) categories of exposure is associated with a 12 gram and 32 gram reduction in mean birth weight, respectively, compared to being born into the lowest (3-6 micrograms per cubic metre) category. However, after adjusting additionally for mother-specific factors, these effects become statistically no different from zero. This holds for other outcomes, including measures of placental health.We find little evidence that exposure to PM 2.5 is related to worse infant health once we adjust as fully as possible for omitted variable bias. We conclude that the association between PM 2.5 and birth outcomes in this population at least partly reflects unmeasured characteristics of families.


Furthermore, TG levels appeared to be positively associated with adiposity indicators among SGA infants but negatively associated with the outcomes among LGA infants . Cord blood lipids levels might be associated with childhood adiposity, and these associations appear to differ across different birth weight categories. If confirmed in future studies, our findings suggest that individualized management plans might be warranted in preventing obesity.We aimed to examine the associations between cord blood lipids and childhood adiposity and to investigate whether these associations vary across birth weight categories , appropriate for gestational age (AGA) and large for gestational age (LGA)) in 1306 infants in the Born in Guangzhou Cohort Study, China. Adiposity outcomes at the age of three years included z-scores of weight-for-length/height (WFLZ), body mass index (BMIZ), subscapular (SSTZ) and triceps skinfold thickness (TSTZ), and the sum of skinfold thicknesses (SSFTZ). Cord blood triglycerides (TG) levels were negatively associated with WFLZ and BMIZ, whereas high density lipoprotein (HDL) levels were positively associated with WFLZ, BMIZ, TSTZ and SSFTZ. These associations were attenuated after adjustment for birth weight. Stratified analyses revealed that total cholesterol (TC) and low-density lipoprotein (LDL) levels were positively associated with childhood adiposity indicators among AGA infants but tended to be negatively associated with the adiposity indicators among LGA infants ( Childhood obesity is a public health concern, whose prevalence increased from 2% in 1980 to 5% in 2015 globally . TherefoMaternal nutrition and intrauterine metabolic environment play important roles in the development of childhood obesity . The intWe have recently reported that infants of different birth weights have distinctive lipids profiles at birth . For exaIn this prospective cohort study in China, we aimed to investigate the associations between cord blood lipid levels and child adiposity indicators at the age of 3 and further to assess if these associations differed by birth weight categories .Baseline characteristics of 1306 mother–infant pairs are shown in p values for interaction, <0.05).p values for interaction, <0.05). Cord blood TG levels were negatively associated with WFLZ and BMIZ among LGA infants. On the other hand, TG levels tended to be positively associated with these outcomes among SGA infants, but the confidence intervals of the regression coefficients are wide and cover zero.Interaction analysis also showed that the associations of TG with WFLZ and BMIZ were different between LGA and SGA infants (n = 58) (n = 48)   or women(n = 48)  were excThis is the first study that examined the association of various cord blood lipids and childhood adiposity measured at the age of three. At first, only TG and HDL-C were found to be associated with several adiposity indicators, and such associations were mostly no longer significant after adjusting for the birth weight of the children. After stratification by birth weight categories, the associations between cord blood lipids and childhood adiposity differed across birth weight groups . Specifically, TC and LDL levels were positively associated with childhood adiposity indicators among AGA infants but negatively associated with the adiposity indicators among LGA infants with marginal statistical significance. Furthermore, TG levels were negatively associated with adiposity indicators among LGA infants but appeared to be positively associated with the outcomes among SGA infants with marginal statistical significance.The relationship between cord blood lipid profile and childhood obesity or adiposity has been rarely studied, and available evidence has focused specifically on the fatty acid composition of cord blood rather than the absolute content of lipids. It has been shown by Donahue et al.  that botUnlike the aforementioned studies, our study used the absolute concentration of various lipid parameters rather than the relative proportion of fatty acids against the total fatty acid pool, which might be more indicative of the metabolic environment that the neonate exposed to in utero at the very last stage of gestation. We found that cord blood TG was negatively associated with WFLZ and BMIZ and that HDL-C was positively associated with WFLZ, TSTZ and SSFTZ without adjustment for birth weight. This is contradictory to a previous report in which the authors found a negative association between cord blood HDL-C and infant weight at six months of age . TheoretIt has been reported that cord blood lipid profile is associated with birth weight or sufficiency of intrauterine growth ,22, implInterestingly, we observed positive associations between cord blood TC and LDL-C and adiposity indicators of those born AGA but negative associations  were found between these factors in children born LGA. Cholestenone, a cholesterol metabolic product in cord blood has previously been associated with rapid weight gain in infants within the first year of life, defined as an increase in weight z-score for more than 0.67 from birth to one year, and this association was independent of birth weight. However, animal models have demonstrated the anti-obesogenic effect of cholestenone supplementation, which prevented the accumulation of fat mass , possiblRecent studies have proposed that lipids during pregnancy are closely related to increased fetal growth . Our obsOur study has a few strengths. The prospective cohort design of our study can reduce the risk of recall bias on data collection. A relatively large sample size ensures sufficient statistical power to explore the relationship between the cord blood lipid profile and the childhood adiposity. We were also able to adjust for several potential confounding factors in the analysis, using data from a well-characterized birth cohort.However, the limitations of our study should also be acknowledged. First, our study population was mainly recruited from a medical center in Guangzhou, and thus, our findings might not be extrapolated to the other populations in China. Second, the anthropometric data of the most recent measurements in routine child care were collected through parental telephone interviews or electronic health record system for about 40% of children. This might have caused potential recall bias or heterogeneity in the growth measurements. Third, a self-reported questionnaire was used to collect data on maternal pre-pregnancy weight and height, which might have led to recall bias. Thirdly, regarding cord blood lipids measurements, we only included the absolute content of lipids. This study could be more complete if both the fatty acid composition and the absolute content of lipids were to be included, considering their diverse biological functions. Fourth, there are a small number of childhood obesity cases in our sample; thus, we were unable to construct a prediction model for childhood obesity, which is clinically relevant. Lastly, data on skinfold thickness were only available in less than half of the children, which might have resulted in selection bias in the analysis for this outcome.This study was part of the Born in Guangzhou Cohort Study (BIGCS), which is a prospective study launched in 2012, based in the Guangzhou Women’s and Children’s Medical Center (GWCMC). The study design and cohort profile of BIGCS have been described previously . Pregnann = 8) and without data on child growth at age of 3 years (n = 403) and covariates (n = 27). Finally, 1306 mother–child pairs were included in the current analysis.Inclusion criteria for the current study were (1) available cord blood samples, (2) available fasting blood samples in mid-pregnancy and data on oral glucose tolerance test (OGTT), (3) no severe disease before pregnancy  and (4) available data on maternal characteristics. A total of 1744 mother–child pairs were randomly selected from all eligible women. This sample has been used in our previous study . We do nAdiposity outcomes included WFLZ, BMIZ, SSTZ, TSTZ and SSFT. Z-scores of WFLZ, BMIZ, SSTZ and TSTZ were calculated based on the Chinese child growth standards . The Z-sTrained research assistants obtained anthropometric measurements at the 3-year follow-up visit (30–42 months). Before measurements, the child was asked to take off their shoes and only keep single-layer clothes. The weight and length of children under 36 months were measured using a Shekel Healthweight™ Scale  in supine position, whereas the weight and height of children at 36 months or older were measured using a Seca 287 digital scale in  standing position. Weight was recorded in kilograms with two decimals, and length/height was recorded in centimeters with one decimal place. After measuring, the weight of clothing (200 g) was subtracted from the weight of each child. Subscapular and triceps skinfold thicknesses were measured using Harpenden skinfold calipers . The sum of the skinfold is the summation of triceps and subscapular skinfold thickness. If the child was unable to attend an in-person follow-up visit in BIGCS, their anthropometric data  of the most recent measurement in routine child care were collected through parental telephone interviews or cross-referenced from the electronic health record system (about 40% in the current sample). The main reason for this non-attendance was reduced motivation for the follow-up at the cohort clinic because the child had recently had visits at other child care clinics. However, data on skinfold thickness were only available among 576 children.Venous umbilical cord blood samples were collected at birth using anticoagulant ethylenediaminetetraacetic acid (EDTA) tubes. Blood samples were centrifuged within 24 h after being collected to separate plasma, which were then stored at −80 °C until analysis. Blood lipid profile was measured in cord blood plasma samples including TC, TG, HDL and LDL. All assays had low intra-day and inter-day coefficients of variation (<2%). Data on cord blood lipids have been used in our previous studies . 2). The diagnosis of GDM was based on the by the International Association for Diabetes and Pregnancy Research guideline [Data on covariates were obtained from questionnaires completed by pregnant women at recruitment, including age (continuous), educational level , pre-pregnancy weight (continuous), height (continuous) and parity (primipara/multipara). Information regarding maternal pregnancy complications , birth weight and sex of the child were sourced from medical records. SGA, AGA and LGA were defined as birth weight of below 10th, 10th to 90th, and above 90th gestational age- and sex-specific percentiles based on the INTERGROWTH-21st standards, respectively . The preuideline ,39. PregWe log-transformed the lipid data to address their skew distributions and then converted them to z-scores based on the mean and standard deviation in the analytic sample to improve the comparability of results between metabolic factors, as they have different units and scales. A multiple linear regression model was used to examine the associations between the level of each cord blood metabolic factor (continuous) and childhood adiposity indicators . Regression coefficients (β) and 95% confidence intervals (CIs) were obtained from two models: model 1 was adjusted for maternal age, parity, education level, pre-pregnancy BMI, GDM, pregnancy-induced hypertension and child’s sex; model 2 was additionally adjusted for birth weight to investigate whether the associations between metabolic factors and child adiposity were independent of the child’s birth weight.To further explore whether the associations between cord blood lipids and child adiposity differed among infants with different birth weights, we stratified the association analysis by birth weight categories . The interaction between lipid measures and birth weight categories on child adiposity was tested by including a product term in the model. We also performed exploratory stratified analyses by maternal GDM status (yes or no) and pre-pregnancy BMI  to investigate whether the association between lipid measures and child adiposity varies by maternal metabolic status.p < 0.05. All analyses were complete case analyses without imputing missing values. In addition, to assess the impacts of preterm birth and pregnancy-induced hypertension on the results, we carried out two sensitivity analyses by excluding preterm infants and hypertensive women, respectively. All analyses were performed using SPSS 21.0, and the statistical significance was set at two-tailed Our study shows that cord blood lipids were associated with childhood adiposity, and these associations might be different among infants of different birth weights. Given the limitations of our study, future studies are needed to confirm our findings, which might have implications in tailored monitoring or intervention strategies for optimal child growth and obesity prevention.


In Western countries, it is common practice for a woman to be supported by a trusted person during childbirth, usually the other parent. Numerous studies have shown that this has a positive effect both on the woman’s satisfaction with the birth process and on physical outcomes. However, there is little research on the birth experience of partners and their wellbeing. The aim of this review is to summarise the existing literature on partner experience, consider its quality and identify the underlying themes.Both a systematic literature search in three databases and a manual search were conducted, for qualitative, quantitative, and mixed-methods studies from Western countries examining the experiences of partners present at a birth.A total of 35 studies were included. Only one study included same-sex partners (the other studies addressed fathers’ experiences only) and only one validated questionnaire examining partners’ birth experiences was identified. Four major themes were found to influence partners’ birth experiences: (1) intense feelings, (2) role of support, (3) staff support, and (4) becoming a father.Partners may feel very vulnerable and stressed in this unfamiliar situation. They need emotional and informal support from staff, want to be actively involved, and play an important role for the birthing woman. To promote good attachment for parents, systematic exploration of the needs of partners is essential for a positive birth experience. Because of the diversity of family constellations, all partners should be included in further studies, especially same-sex partners.The online version contains supplementary material available at 10.1186/s12884-022-05014-1. Until the 1980’s, childbirth was considered “women’s business”. For this reason, as well as because of strict hygiene regulations, partners were not desired or encouraged to attend the birth . The parThe majority of partners want to participate in the birth of their child and support the women . PartnerIn contrast to the body of knowledge outlined above, partners often receive little attention and are not always involved during childbirth , 13. TheLack of communication between partners and medical staff and the feeling of exclusion can lead to a negative birth experience for the partner . A negatWhile in low-income countries very low caesarean section rates with a high maternal mortality risk are reported, in high-income countries caesarean section rates have risen sharply since the 1970s . In manyIn 2018, the World Health Organization published a guideline with evidence-based recommendations for low-risk births . The goaThe companionship of a close person has been shown to be important for birthing women –32. CompNowadays, in most Western countries, it is common for expectant fathers to be present in the birthing room and to actively participate in their partner’s labour and birth . While tThis scoping review therefore aims to identify, review and synthesise the literature on the experiences of partners during childbirth in clinical settings in Western countries in order to identify the different themes and subthemes, which influence these experiences.We used the design of a scoping review since it maps the key concepts underlying an area of research and the main sources and types of available evidence . ScopingWhat are the experiences of partners attending the birth of their child in clinical settings in Western countries?Although heteronormative relationships are the most common type of relationship and thus the father is the most common companion, diverse constellations of relationships exist. For this reason, we searched for the experience of partners in general. However, with the exception of one study, we found only studies that examined the experiences of fathers. For this reason, we refer to fathers in this review.The beginnings of partner birth attendance 1980s are not comparable to today`s birth attendance. For this reason, and due to societal changes regarding the inclusion of fathers and equal parenting, especially from the turn of the millennium onwards, we conducted a review of the literature published after 2000. Initial searches were conducted in Medline via PubMed and CINAHL and in the midwifery digest MIDIRS in May 2021. To find additional relevant studies, we manually searched the Internet and used citation tracking. Since this work is a preliminary work for the development of a German language questionnaire for partners during childbirth, we were strongly interested in what publications have appeared in Germany on this topic. For this reason we manually reviewed professional journals in the field of maternity care published in Germany via database Thieme publisher. The search terms (Table (“labour companionship”[tiab] OR companion*[tiab] OR father*[tiab] OR husband*[tiab] OR “birth partner*”[tiab] OR “support person” OR spouse* OR spouses[MeSH]) AND (well-being[tiab] OR wellbeing[tiab] OR welfare[tiab] OR emotion*[tiab] OR affectiv*[tiab] OR psychologic*[tiab] OR experienc*[tiab]) AND (labour[ti] labor[ti] OR birth*[ti] OR childbirth[ti] OR parturition[ti] OR parturition[MeSH]).We considered as eligible all qualitative, quantitative and mixed-method studies which examined the birth experiences of partners in the clinical setting, whether or not it was their first attendance at a birth. Any published language was included. Table https://unstats.un.org/unsd/methodology/m49/). Since obstetric care in Eastern European countries and North and South America differs greatly from that in Germany, studies from these countries were not included, nor were studies from developing countries.For comparability, studies were included from Western countries, covering Northern, Western and Southern European countries, Australia, New Zealand, and Canada (for a detailed list of related countries see: Two independent researchers (NSch and SStr) extracted the data. First, all titles and abstracts were checked for inclusion, and the included studies were then reviewed for relevance using the full text. Disagreements between researchers were resolved through discussion and consensus. If necessary, the opinion of a third researcher (GA) was obtained. Researchers extracted information on study characteristics using a piloted data extraction form. Data extraction included information about the authors and year, the country in which the study was conducted, a description of the participants, the birth modes included in the study, information about which method was used to examine the birth experience and a summary of the results found.Due to heterogeneity in study design and quality, various birth experience themes were categorised and described. Some sources addressed experiences during pregnancy or postpartum in addition to the birth experience. Here, only evidence related to the birth experience was extracted. If both mothers and fathers were interviewed in the publication, we considered only the experiences of fathers, also in comparison to mothers, whenever possible.In order to identify recurring themes regarding birth experiences, the main results of all included studies were first recorded in a comprehensive table. Then, similarities and differences in the data were systematically identified by rereading the studies’ main results. Obvious recurring themes were first colour coded. Subsequently, each main result was assigned to a theme. Four themes common across all studies were identified.Because we combined qualitative, quantitative and mixed-methods studies, we used the Mixed Methods Appraisal Tool (MMAT) to assess the quality of the studies . ScreeniThe flow chart of the literature selection Fig.  providesThe majority of the qualitative studies used open or semi-structured interviews, two of them in combination with observation. In the included mixed-method studies, data were collected mainly through closed- and open-ended questions. Most quantitative studies were conducted with self-developed questionnaires. In one case the Salmon’s Item List was adapted to men , and in Four main themes relate to fathers’ experiences of clinical birth: Intense feelings, the role of support, staff support, and the becoming a father. Table Almost all included studies report intense feelings among fathers. The most commonly reported feelings are anxiety, ranging from worry to fear, and helplessness , 74, 75.While some studies show that fathers who already have children are less fearful , BradleyFathers feel vulnerable and highly stressed in this unknown situation , 67 and The environment also has an impact on fathers’ feelings. Men state that the unfamiliar environment in a hospital birthing room causes discomfort  or critiOther factors affecting fathers’ feelings are the impacts of the birth process itself. Experiencing interventions or witnessing complications is perceived as stressful and difficult , 72. MenDespite these negative feelings, many of the included studies report positive overall experiences for fathers , 51, 58.The studies comparing the experiences of fathers and mothers all concluded that the overall experience was the same for both parents, but that they differed on individual subthemes , 46–48. The feelings reported by fathers also relate to the role they assumed during childbirth. Johnson report higher levels of stress in men who did not fulfil their expectations of the role .emotional support by being present and offering conversation, physical support by aiding different birthing positions or easing mobility, and informational support by mediating between staff and the woman [In five studies, the majority of men were found to have felt helpful and important in supporting the woman giving birth , 69, 75.he woman , 65. Thehe woman , want tohe woman , but arehe woman . It can he woman . Sometimhe woman , 74. Sevhe woman , 62 and he woman , 63, 64.he woman .It is typical for the man to put his own needs aside and to hide own feelings . The rolobserver role , a carer role , an intermediary role (facilitating information sharing) and an advocate role (representing the woman’s needs by advocating for her) [Studies attempting to classify different roles describe, for example, an for her) .The environment influences the role of support people by either providing a place to be present and responsive to the woman’s needs or by preventing closeness . Technolinformation, especially about the birth process, particularly for those who are unmarried, have a lower education status, and for first-time fathers [The behaviour and communication of medical staff are described as having a strong influence on partners’ feelings . The fat fathers . In Egge fathers . Hilding fathers . Prember fathers . The inf fathers , 66, 70. fathers , for exa fathers . They wa fathers .In addition to information, emotional support and acceptance are important factors . FathersFathers frequently report low professional support –58, 76. In contrast, other studies report that midwifery care, opportunities for participation and decision-making were better than expected or needed ; staff cInvolvement in care, trustworthy and supportive staff , satisfaWhile some studies find no difference in fathers’ ages , 69, othThe moment of birth is described as a life-changing and overwhelming moment characterised by feelings of love and belonging , 65. Theintense feelings reported by the fathers after the birth. During the birth process, the fathers describe strong negative feelings, especially fear and being overwhelmed. The birth of the child, on the contrary, is described as the most beautiful event of their lives. Premberg et al. describe this essential meaning of the experience as an ‘interwoven process pendulating between euphoria and agony’ [becoming a father. The remaining two themes are the role of support and staff support. These two are closely related, as staff support has a significant impact on the role of the support person.This scoping review presents the quantitative, qualitative and mixed-method findings on fathers’ birth experiences in the clinical setting. Four important themes were found to influence fathers’ birth experiences, enhance their well-being, and promote an active and thus more satisfying role. One theme deals with the d agony’ . These pFenwick et al. found that the desire for support from staff was expressed in advance when men were asked about their expectations for the birth, as confirmed in this review . PartnerIf men do not receive support, they may take a very passive role, feel helpless and as a result not experience a positive birth. Women equally want an active partner to go through the birth process with them . They nePrevious studies have reported that support people felt unprepared for the intensity of the unpredictable birth process and the resulting fears regarding the health and life of the partner and child . In addiThe evidence regarding different birth modes was inconsistent, particularly with respect to caesarean section. While in some studies caesarean section was found in general to lead to a more negative birth experience, others reported that elective caesarean section led to a positive birth experience. Many of the studies included here focussed on spontaneous vaginal births and excluded other birth modes from the outset. Studies focusing on the fathers’ experience with caesarean birth found that they want to receive information and be involved in the decision-making process . What isStudies focusing on a non-clinical setting were excluded from this scoping review. Fathers present during a home birth report different feelings, in particular greater active mental and physical involvement . In LindThe present review has some potential limitations. First, the methodological quality of the studies varied, which may have influenced the results presented here. For example, the sample size of most of the quantitative studies included was small and the questionnaires used to capture birth experiences of partners were often not validated. Second, although the focus was restricted to Western countries, comparability between different healthcare and obstetric systems is limited. Results should therefore be considered with caution. Third, some studies do not specify at what time after birth the data collection took place. Thus, no conclusion can be drawn about potential recall effects in these studies. Fourth, a number of the studies reviewed were Swedish, therefore the Swedish context may be overly represented. In Sweden, fathers’ involvement is generally considered a social ‘norm’ . This maIt is important to consider the woman, the partner and the couple as three separate and individual units. The active role of the support person should be encouraged, as they are more likely to feel useful and thus more satisfied with the birth process. To this end, the support person needs emotional and informal support from the staff. He or she needs information to reduce fears and anxieties and instruction on how to support the woman. Given the prevailing shortage of midwives and work overload of clinical staff, the wellbeing and role of the support person should be systematically studied and promoted. Results are sometimes inconsistent and studies with validated questionnaires are lacking. Systematic research should be conducted on what support people need to achieve a positive birth experience. Further, studies should be conducted which include all support people and do not focus exclusively on fathers.Additional file 1. PRISMA_ScR Checklist.Additional file 2. Critical appraisal.


Manitoba has one of the highest incarceration rates among Canadian provinces, and because of Canada’s racist and colonial policies, the number of Métis women in custody is disproportionately high. In this study, we examined birth outcomes among Métis and all other Manitoba women who were incarcerated while pregnant.Using linked administrative health and justice system data, we developed a 2004-2017 cohort of mother-infant dyads with a live birth . We identified all Métis mother-infant dyads, and then divided them into 3 mutually exclusive groups: a) prenatal incarceration; b) post-natal incarceration; c) no incarceration. We developed matched comparison groups for each exposure based on Métis identity, maternal age, geography and income, and, after adjusting for other potentially confounding variables , we examined risk differences in birth outcomes among Métis women and infants between exposure groups.The cohort included n=534 mothers who were incarcerated while pregnant (a), n=1,677 mothers incarcerated postnatally (b), and n=14,084 mothers never incarcerated (c). When we compared prenatal vs postnatal incarceration (a vs b), we found that women incarcerated during the prenatal period were more likely to have a low birth weight infant , preterm birth  or Caesarean birth  and were less likely to have a large-for-gestational-age infant  or to initiate breast feeding . In the prenatal vs no incarceration comparison (a vs c), the same outcomes were statistically significant as above; however, the risk differences were even more pronounced.Prenatal incarceration is associated with poor birth outcomes for all mothers and infants in Manitoba; however, Métis women and children are disproportionately affected, further perpetuating inequities they may already experience. Canadians must acknowledge the harms of racist policies and practices, and work to support the health and well-being of Métis people.