The widespread application of high-resolution chromosome detection technology in clinical practice has identified many variants of unknown significance (VOUS) in prenatal diagnosis. The purpose of this study was to prospectively analyze the chromosomal results of parents and the follow-up information of pregnancy outcomes of prenatal samples with VOUS, so as to determine the influence of the detection of parent-of-origin on the pregnancy outcomes of fetuses with VOUS. The present study analyzed amniotic fluid samples obtained from women with different risk indications between February 2017 and December 2018. The samples were subjected to copy number variation sequencing, and detection of parent-of-origin was suggested in cases of samples with VOUS. The pregnancy outcome was followed up. In a total of 14073 amniotic fluid samples, 729 cases of VOUS were detected  and 721 cases were followed up successfully. Among the 721 cases, 525 patients agreed to detect the parent-of-origin . It was revealed that the VOUS in 460 of the fetuses were hereditary . The percentages of abnormal pregnancy outcomes  in the inherited, de novo, and refusal to detect the parent-of-origin (i.e. unknown origin) groups were 4.3% (20/460), 6.2% (4/65), and 6.6% (13/196), respectively. There was no significant difference among the three groups (P > 0.05). The rate of voluntary termination of pregnancy (TOP) in the unknown origin group was significantly higher than that in the group that had determined the parent-of-origin . There is currently no evidence that suggests that the proportion of abnormal pregnancy outcomes is higher in fetuses with VOUS than in other fetuses. However, the present study revealed that determining the parent-of-origin affects the decision to undergo voluntary TOP, as the rate of voluntary TOP in the group that refused detection was higher than that in the group that consented. The incidence of birth defects in China is ~5.6%3, and chromosomal aberrations account for >80% of the genetic causes of birth defects4. At present, >300 chromosomal microdeletions or microduplication syndromes caused by pathogenic copy number variation (CNV)6 have been described, and the combined incidence rate is nearly 1/6005, accounting for half of the birth defects caused by chromosomal aberrations4.Since its introduction in 1970, amniocentesis remains the most commonly used invasive prenatal diagnostic tool; it is primarily used for the prenatal diagnosis of fetal chromosomal diseases, single gene diseases, and congenital metabolic diseases12. The application of CMA and CNVseq in the prenatal population provides additional and clinically significant cytogenetic information compared with conventional karyotyping. CMA and CNVseq have an additional detection rate of 1–6% for clinically significant CNVs17 and may also identify variants of unknown significance (VOUS), with a detection rate of 1.4–3.4%17. VOUS refers to the genomic variation that cannot be accurately explained based on the current understanding of the human genome and available databases. Therefore, it may be necessary to investigate the parents’ genome and perform a comprehensive analysis of the family, to aid the interpretation of the fetal test results18.Chromosomal microarray analysis (CMA) is a classical method used to detect CNVs in the genome, particularly abnormal submicrostructures. The advent of affordable and rapid next-generation sequencing has transformed prenatal diagnosis. At present, high-resolution chromosome detection techniques such as CMA and copy number variation sequencing (CNVseq) are widely used in fetal chromosome detection in ChinaIn this study, we prospectively analyzed the results of parent-of-origin detection and the follow-up data of pregnancy outcome of fetuses with VOUS, as detected by CNVseq technology. The results may shed light on the influence of the detection of parent-of-origin on the pregnancy outcomes of these fetuses and provide practical suggestions for prenatal fetal chromosome detection schemes and genetic counseling.In total, 14073 amniotic fluid samples were analyzed between February 2017 and December 2018, and 729 cases (5.2%) of VOUS were detected. Among these, 8 cases were lost to follow-up and 721 cases were included in this study. The average age of the pregnant women was 31.1 years , and the average gestational age at amniocentesis was 22.4 weeks .The parents of 525 fetuses with VOUS agreed to detect the parent-of-origin . It was revealed that 87.6% (460/525) of the fetuses inherited the CNV from the father or mother; in total, 51.0% were maternal, 34.9% were paternal, 1.7% were parental and 12.4% were de novo. The parents of 196 fetuses (27.2%) refused to detect the parent-of-origin, mainly owing to too worried about the adverse risks of VOUS to the fetuses and late pregnancy. After excluding the presence of VOUS in the sex chromosome (113 cases), 608 cases were identified in the autosomal chromosomes. Among the 608 cases of autosomal VOUS, 445 cases agreed to detect the parent-of-origin, and maternal, paternal, parental, and de novo VOUS accounted for 49.0, 35.5, 1.6, and 13.9%, respectively. In total, 163 cases (26.8%) refused to detect the parent-of-origin. The results showed that VOUS in the sex chromosomes had no significant effect on the parents’ decision to detect the parent-of-origin. In addition, the characteristics  of fetal CNV in the consented to detection of parent-of-origin group and the rejection group were compared, there was no statistical difference between the two groups (P > 0.05), as shown in Table 2 = 7.961, P = 0.005). The pregnancy outcomes of the 721 cases with VOUS are presented in Table In the present study, abnormal pregnancy outcomes included preterm delivery, developmental delay, hemangioma, hearing impairment, congenital heart disease, brain tumors, eversion of the umbilicus, polydactyly, neonatal death, termination of pregnancy (TOP) due to fetal pathological factors , and pregnancy loss. The rate of abnormal pregnancy outcomes was 4.3% 20/460) in the inherited group, 6.2% (4/65) in de novo group, and 6.6% (13/196) in the unknown origin group. There was no significant difference among the groups . The rate of voluntary TOP was 7.4% (39/525) in the group that consented to the detection of parent-of-origin (i.e. the sum of the inherited and de novo groups) and 14.3% (28/196) in the rejection group (i.e. unknown origin group). The rate in the latter group was significantly higher than that of the former  of the fetuses inherited the CNV from the father or mother without abnormal phenotype, the pathogenicity of CNVs in these samples should be changed to likely benign. Among the 721 cases with follow-up results, the proportion of parents who refused to detect the parent-of-origin was 27.2%, mainly owing to too worried about the adverse risks of VOUS to the fetuses and late pregnancy. In this study, amniocentesis was performed on some samples when they were >25th gestational week, the reason for chromosome examination of these samples was abnormal fetal ultrasound findings. At present, the ultrasound screening of fetal malformations in our country is mostly performed at 22–24 gestational weeks, so most of the fetal ultrasound abnormalities are usually found at this time. In addition, due to the large population of our country and few hospitals with amniocentesis qualification in our province, pregnant women usually need to line up for amniocentesis, so they cannot receive surgery in time. Therefore, we hypothesized that if the parent-of-origin was detected in all the samples, the actual proportion of VOUS samples may be lower.In total, 14073 amniotic fluid samples were analyzed in the present study, and 729 samples (5.2%) with VOUS were identified. The parents of the affected fetuses underwent CNVseq, and the pathogenicity of CNV was analyzed again. The VOUS ratio decreased to 1.9% (265/14073), which was similar to the VOUS ratio reported in the literature3. It has been estimated that 7.9 million children are born with a serious birth defect of genetic or partially genetic origin annually, accounting for 6% of the total number of births worldwide19. The results obtained in the present study showed that the rate of abnormal pregnancy outcome was 4.3% in the inherited group, 6.2% in the de novo group and 6.6% in the unknown origin group. There was no significant difference among the groups, and there was no other evidence to suggest that the risk of abnormal pregnancy outcomes in samples with VOUS were higher than those in other samples. According to the follow-up results, the proportion of pregnancy loss or fetal death in the 721 samples was 0.8% (6/721). A Danish randomized controlled trial showed that the rate of fetal loss was 1.7% in the amniocentesis group and 0.7% in the control group, with a 1.0% procedure-related net risk20. A meta-analysis revealed that the weighted pooled procedure-related risk of miscarriage for amniocentesis was 0.11%21. A previously published study investigating 147987 invasive procedures in Denmark reported that the rate of miscarriage within 28 days after amniocentesis was 0.56% and that the risk of stillbirth within 42 days was 0.09%22. Compared with the aforementioned studies, VOUS does not seem to increase the risk of pregnancy loss or fetal death after amniocentesis. However, certain patients in the present study chose to undergo a TOP without detection of the parent-of-origin. The proportion of pregnant women choosing to terminate pregnancy voluntarily in de novo group was very high , so we were unable to investigate pregnancy outcomes in these cases. In addition, with the completion of the human genome map23, a large number of VOUS may be related to several clinical phenotypes24. Therefore, in fetuses with VOUS, it is recommended that clinicians increase patient monitoring, via examination and ultrasounds, and perform timely interventions and intrauterine treatment if necessary. Additionally, more intensive follow-up is required after birth.In this study, abnormal pregnancy outcomes included preterm delivery, developmental delay, hemangioma, hearing impairment, congenital heart disease, brain tumors, eversion of the umbilicus, polydactyly, neonatal death, TOP due to fetal pathological factors , and pregnancy loss. At present, a direct association between abnormal pregnancy outcomes and CNVs carried by the fetus cannot be established. The incidence of birth defects in China is ~5.6%The present study revealed that there was no statistical difference in the proportion of abnormal pregnancy outcomes among the inherited, de novo and unknown origin groups. The rate of voluntary TOP was 7.4% among patients who consented to detect the parent-of-origin, and 14.3% in patients who refused this approach. This difference was statistically significant (P = 0.005). The samples included in the “voluntary TOP” group refer to the samples without any other pathogenic abnormality  except the CNV before pregnant women choose TOP. There was no significant difference in CNV characteristics and genetic counseling among groups, and no other factors that might lead to different pregnancy outcomes were found. The proportion of normal infants in the group of patients who consented to detect the parent-of-origin was 88.6% (462/525). Theoretically, the fetal outcome of the rejection group should be similar to that of consent group. However, compared with women who detected the parent-of-origin, a higher proportion of women who did not detect the parent-of-origin chose to voluntarily terminate their pregnancy, resulting in a lower proportion  of normal infants in the rejection group , as healthy fetuses may have also been terminated.27, women who perform fetal chromosomal detection in late pregnancy should consider carrying out CNVseq of parent-child trios (trio-CNVseq). This approach may not only shorten the time to obtain the test report but may also produce more clear amniotic fluid chromosomal results, which can help relieve the anxiety of pregnant women and assist in the selection of an appropriate treatment plan. However, this proposal requires further analysis to comprehensively evaluate the health benefits and economic feasibility.In conclusion, there is currently no evidence that suggests that the pregnancy outcomes of women with VOUS samples are worse than those of general pregnant women. Instead, parents with VOUS samples should detect the parent-of-origin in a timely manner to further establish the pathogenicity of VOUS. Economic resources permitting, we can learn from the detection strategy of whole exome sequencing in the field of identifying pathogenic genes of children’s rare diseasesThis study investigated amniotic fluid samples obtained from women with different risk indications in the West China Second University Hospital of Sichuan University between February 2017 and December 2018. Risks included advanced maternal age, increased risk of a screening test, abnormal ultrasound findings, obstetric history , family history  or maternal request. The study was approved by the Medical Ethics Committee of West China Second University Hospital of Sichuan University, and all experiments were performed in accordance with relevant guidelines and regulations. All pregnant women received genetic counseling and signed informed consent.According to routine operation specifications, 20 ml amniotic fluid was extracted and placed into four sterile centrifuge tubes. CNVseq and quantitative fluorescence PCR (QF-PCR) were performed on two tubes, and the remaining two tubes were stored at 4 °C. DNA was extracted from the amniotic fluid using a DNeasy Blood and Tissue Kit , according to the manufacturer’s instructions. QF-PCR detection was performed using 21 trisomy/sex chromosome/polyploid and 18 trisomy/13 trisomy/polyploid detection kits , according to the manufacturer’s instructions. If the results of QF-PCR indicated that there were maternal cells in the samples, CNVseq and QF-PCR were performed on the spare samples after cell culture.14. In this study, the pathogenicity of CNVs >100 kb was analyzed. The clinical significance of the CNVs was interpreted according to the standards and guidelines for the interpretation of sequence variants recommended by the American College of Medical Genetics and Genomics and the Association for Molecular Pathology18. By searching the DGV (http://dgv.tcag.ca/), Decipher (https://decipher.sanger.ac.uk/), Clingen (https://www.ncbi.nlm.nih.gov/projects/dbvar/clingen/), and OMIM (http://omim.org/) databases and combining these data with fetal ultrasound results, we preliminarily classified the pathogenicity of CNVs into five categories: benign CNVs, likely benign CNVs, VOUS, likely pathogenic CNVs, and pathogenic CNVs.The DNA library was obtained using the Chromosome CNV Detection kit  and was subsequently sequenced on the Illumina Nextseq 500 sequencing platform  using the Nextseq 500 High Output kit . Finally, we compared the reads obtained by sequencing with the human reference genome and performed bioinformatics analysis to obtain the genomic copy number information of the samples as previously describedWhen VOUS were identified in the amniotic fluid samples, we recommended that the biological parents of the fetus underwent CNVseq  to determine the origin of the CNV of the fetus. The DNA extraction and CNVseq methods were performed as described for the amniotic fluid samples. Some samples had multiple CNVs at different genomic locations, if some of the CNVs in a sample were from the father and other CNVs were from the mother, the origin of the CNVs in the sample was “parental”. If the fetal CNV was inherited from the father or mother without abnormal phenotype, the pathogenicity of the CNV was likely benign. If the fetal CNV was De novo, the pathogenicity of the CNV was still VOUS.One year after amniocentesis, the mother or father of the fetus was contacted by telephone. The contents of the inquiry include: fetal ultrasound results during pregnancy, pregnancy complications of pregnant women, whether pregnancy loss, whether TOP and the causes, date of delivery, mode of delivery, weight and length of the newborn, the Apgar score, whether the appearance of the newborn was abnormal, feeding conditions after birth, examination results of pediatric outpatient service. The flowchart of the study is shown in Fig. We confirm that informed consent was obtained from all participants and/or their legal guardians.


Environmental surveillance, which relies on a limited number of sampling sites in the Central African Republic and does not cover the whole country, failed to detect the circulation of VDPV-2s before some had induced poliomyelitis in children.Since May 2019, the Central African Republic has experienced a poliomyelitis outbreak caused by type 2 vaccine-derived polioviruses (VDPV-2s). The outbreak affected Bangui, the capital city, and 10 districts across the country. The outbreak resulted from several independent emergence events of VDPV-2s featuring recombinant genomes with complex mosaic genomes. The low number of mutations ( Enterovirus C (https://polioeradication.org) managed to eradicate wild poliovirus of 2 of the 3 serotypes and to contain virus of the third serotype in Pakistan and Afghanistan. The Initiative relies on 2 pillars: surveillance of poliovirus circulation and vaccination. Contrary to the inactivated polio vaccine, the oral polio vaccine (OPV) induces strong intestinal immunity that blocks transmission of poliovirus in subsequent infections , we detected VDPV-2s in fecal samples of 19 children with acute flaccid paralysis (AFP). Positive samples came from 10 districts across the country, including Bangui, the capital city (>6 mutations within the VP1-encoding sequence). Given the evolutionary rate of this genomic region  were free of recombination events and feature a global nucleotide divergence <1% compared with Sabin-2. The 66 other CAR VDPV-2 genomes comprised sequences derived from Sabin-2 and from other nonpolio enteroviruses in 12 recombinant patterns; polio/nonpolio breakpoints were within the 2A, 2B, 2C, 3A, 3C, and 3D-encoding regions Figure. IAlthough VDPV-2s commonly harbor a recombinant nonpolio 5′ untranslated region (UTR), all CAR VDPVs had a 5′ UTR from the vaccine Sabin-2 strain. Nonetheless, an A→G reversion was found in all genomes at nt position 481, which harbors one of the major determinants of attenuation of the Sabin-2 strain , was synchronized globally (We show that the CAR VDPV-2 outbreak resulted from several independent emergence events, involving recombinant genomes with no recombination in the 5′ UTR. Beyond the situation in CAR, 2019 was a dark year for the Global Polio Eradication Initiative; VDPV-2 outbreaks surged in many countries in Africa (Phylogenetic tree for type 2 vaccine-derived polioviruses, Central African Republic, 2019.


It has been suggested that the intergenerational associations in gestational age at delivery are considerably affected by temporal changes in the environmental conditions. We explored whether changing environment affects familial resemblance of gestational age at delivery. Understanding how correlation changes in different settings allows to design better studies aimed to detect genes and environmental factors involved in the parturition process. The Swedish Medical Birth Register was used to retrieve births during 1973–2012. In total, 454,433 parent-child, 2,247,062 full sibling, 405,116 maternal half-sibling and 469,995 paternal half-sibling pairs were identified. A decreasing trend in correlation, associated with increasing age gaps, was observed among all siblings, with the largest drop for full siblings, from ρ = 0.32 : 0.31, 0.33) for full siblings with one-year gap to ρ = 0.16  for full siblings with age gap above 20 years. A variation in association between full siblings born up to two years apart was observed; estimate ρ = 0.28  in 1973, and ρ = 0.36  in 2012. Observed variability in the association in gestational age at delivery between the relatives with respect to their birth year or age gap suggests the existence of temporally changing environmental factors. In 2012, World Health Organization representatives called for action aimed at preterm delivery (PTD) prevention . One difThe aim of this study was to assess the presence and significance of time-related environmental  factors for the degree of association between gestational ages at delivery of relatives. For that purpose, distributions of gestational age at delivery of relatives were compared with regard to their birth years or age gaps. Next objective was to analyze the changes in the correlation estimate among relatives born in the periods of time characterized by different gestational duration distributions, and among full siblings with regard to birth years and hospital of delivery.This study is based on a sample of pregnancies (and relevant pregnancy characteristics) reported in the Swedish Medical Birth Register (MBR ) during Data cleansing, involving removal of missing information from the best MBR estimate of gestational duration, birth year and identification number, as well as limiting the sample to live-born singleton pregnancies were the first steps before creating datasets appropriate for the analysis of parent-child, full sibling, maternal half-sibling, and paternal half-sibling pairs.In this paper, under the term “environmental factors”, it is referred to all non-genetic factors. In order to exclude commonly acknowledged intergenerational effect  factors, the full sibling sample was limited to non-iatrogenic deliveries and to neonates that survived up to 28 days after delivery. Iatrogenic delivery was defined as birth after induced onset of labor or a cesarean section before the spontaneous onset of labor . Spontaneous delivery was defined as birth after spontaneous onset of labor . Births with unclassified mode of delivery were excluded from analysis.Distributions of gestational age at delivery among relatives were compared by Q-Q plots in order to detect whether environmental conditions change. Associations between relatives were obtained from correlation analysis. Differences in the correlations between relatives born in different periods of time might be due to differences in the age of their mothers during pregnancy and her parity. In order to assess the existence of other time-related environmental factors, gestational age at delivery duration was adjusted for the maternal age at delivery, parity. The adjustment consisted of two steps, estimating the effect of maternal age and parity on gestational duration, and adjusting gestational duration in a way as if all births were to a woman of age between 20–30 years old and of parity two. More about gestational duration adjustment are found in For the analyses of relatives born in different periods of time, the distinct birth year periods were determined based on the alterations that occurred in the population gestational duration distribution. In this paper, distinct (minimum 10 years difference) periods of birth years were called closely and widely spaced accordingly to the degree to which population gestational duration distribution differed  or overlapping (sibling pairs) birth years . All famDistribution differences were detected among all types of family member pairs . In the Correlation estimates for closely and widely spaced periods differed significantly in the samples of full siblings , maternal half-siblings , and mother-child pairs . The strongest change in the association magnitude was in the samples of full siblings and maternal half-siblings, from ρ = 0.23  to ρ = 0.3  and from ρ = 0.18  to ρ = 0.24 , respectively , For th. Mother-Significantly decreasing trend in correlation estimates, associated with increasing age gaps, was observed among all siblings . This paDifferences in distributions were observed among full siblings, regardless the age gap between them. In the QQ-plot for full siblings born at most seven years apart, the curve was above the diagonal line indicating that more PTD children were in the cohort of older sibling  = 1.41, 95%CI: 1.31, 1.51, n = 256,868). A small increase was also found for the fathers and their first child . When restricting the sample to siblings of the first and second parity, there is an increased risk for a child to be born preterm if his/her full- or maternal half-sibling was born preterm as well . No increase was found for paternal half-siblings .The main finding of this study is variability in the correlation between gestational ages at delivery in relatives, after stratification by their birth years. The association between maternal and child’s gestational age at delivery is significantly lower if there are large gaps in their ages, even after adjustment for maternal age at delivery and parity. Similarly, the same significantly decreasing trend in the degree of association with increasing age gap was observed among siblings. Variability in the correlations over the years was also observed among full siblings born up to two years apart. This heterogeneity of associations was observed both when it came to correlations based on unadjusted gestational age and adjusted for maternal age and parity. The extent to which correlations varied also depended on the extent to which the distributions of the cohorts of relatives differed. The pattern of larger distribution differences and larger decreases in the degree of association was observed among mother-child, but not father-child, pairs. It is possible that the low correlation estimates among the father-child pairs prevented detection of this variation. Similarly, in the case of siblings, the association decreased with age gap among those with relatively high overall correlations, e.g. full siblings and maternal half-siblings, but not paternal half-siblings. Our finding of a lower correlation among paternal half-siblings compared with full siblings or maternal half-siblings once again suggested that the genetic control of gestational duration comes mainly from the maternal side ,6,9. In Different researchers have expressed various opinions about the effect of time-related environmental factors on the estimates of association between the relatives as well as on heritability. While some think that time-related environmental factors have no effect on the association estimates , others th to 42nd week of gestation) in how normal pregnancy duration is defined [While there seems to be considerable interest in understanding the composition of observed parent-offspring associations, there is, to our knowledge, no previous study analyzing these associations with regard to birth years of relatives. Some ,8,18–22, defined , there i defined  to repreWhile analyzing the variability of the association between relatives, the best estimate of gestational duration provided by the MBR was used. The MBR best estimate selection is based on assumptions about the accuracy of various methods . Since tDue to poor reporting on the mode of onset of delivery during certain periods in the MBR, the determination of the onset of delivery (spontaneous or iatrogenic) might be subject to misclassification. Mode of onset of delivery began to be reported in the MBR in 1990. Therefore, in this study, onset of delivery before 1990 was assessed based exclusively on ICD codes. Additionally, in the MBR, the information required to calculate maternal BMI is consistently available only from 1992 what rules out parent-offspring and limits the analyses to sibling pairs.Observed variability in the association in gestational age at delivery between the relatives with respect to their birth year or age gap suggests the existence of temporally changing environmental factors.S1 TableTable presents estimates and 95% confidence intervals (CI) for maternal age category, and parity. The reference group were 20–30 years for maternal age  and two for parity . Gestational duration, reported in Swedish Medical Birth Register, was adjusted accordingly to the expected shift from the reference population, i.e. women giving birth at age between 20 and 30 years old and of parity two.(DOCX)Click here for additional data file.S1 Figth) of gestational duration distribution were plotted over the years 1973–2012 . Based on the visual assessment of gestational duration distribution, the periods of birth years in the cohorts of parents and their children were selected so that relatives were born in the periods of time characterized by more (black rectangle) and less (pink rectangle) similar distribution. Same was done for all sibling pairs. The upper part of a graph shows birth year periods in the cohort of parents and their offspring, the lower part of a graph shows birth year periods in the cohort of siblings. In the paper, cohorts of relatives born in the periods of time characterized by less or more similar gestational duration distributions were called as relatives matched from widely or closely spaced periods of time.Birth-years (black or pink rectangles) in the cohorts of paired relatives were selected based on gestational duration distribution in the population . Nine percentiles Click here for additional data file.S1 AppendixAppendix includes results of correlation analyses performed on gestational duration adjusted for maternal body mass index.(PDF)Click here for additional data file.


The incidence of preterm birth  has been increasing in China and many other countries in recent years. However, the causes of the increase were not well understood. The current study aims to examine the contribution of maternal age, period of delivery, and maternal birth cohorts to long-term trends in preterm birth in Guangzhou, China.In a retrospective population-based study, data were obtained from 2,535,000 singleton live births with 20–43 gestational weeks from 2001 to 2016 and recorded in the Guangzhou Perinatal Health Care and Delivery Surveillance System, in China. The age-period-cohort models were applied to investigate the temporal changes in incidences of PTB, stratified by parity.The incidence of preterm birth steadily increased from 5.1% in 2001 to 5.9% in 2016, with larger rise in primiparous mothers (from 5.0 to 5.9%) compared to multiparous mothers (from 5.6 to 5.9%). A J-shaped and a V-shaped relationship were found between maternal age and PTB among primiparous and multiparous mothers, respectively. A linear cohort effect was found among primiparous mothers with the lowest risk of PTB  in 1961 and the highest risk  in 1997 compared to the mothers born in 1981. An inverse U-shaped association between maternal birth cohort and PTB was found in multiparous mothers. There were weak decreasing period effects on the trend of overall PTB among multiparous mothers and on the trend of extremely (< 27 weeks) or very (28–31 weeks) PTB among both parity groups during the period of 2001–2012.Our findings showed the PTB incidences had been increasing in the past 16 years in Guangzhou, China and both maternal age and cohort effects contributed to these trends. Further studies are recommended on the impact of altered maternal age and parity on premature births and corresponding public education and public health policies.Supplementary information accompanies this paper at 10.1186/s12889-020-09739-6. Preterm birth (PTB), defined as births before 37 completed gestational weeks, is an important global public health issue. It is estimated that 14.84 million newborns were born to preterm in 2014 worldwide, accounting for 10.6% of all live births [Reasons for the rising trend of PTB around the world in recent years –7 remainMaternal age at childbirth has been increasing and the distribution of parity has altered over the past decades in China due to the relaxation of the one-child policy , 12. RecThe present study aimed to examine the contribution of these 3 time-dependent factors to the long-term trends in PTB from 2001 to 2016 in Guangzhou, China. We also assessed whether the complex effects were modified by parity.n = 2,553,803) at 20–43 gestational weeks from 2001 to 2016 were retrospectively obtained from the Guangzhou Perinatal Health Care and Delivery Surveillance System [n = 1947), born either before 1961 or after 2000 (n = 411), non-Mainland Chinese (n = 8976) and with missing data on maternal age (n = 1881), parity (n = 2815), newborn’s sex (n = 2050) and birth weight (n = 723), resulting in 2,535,000 singleton live births in the present study. The study was approved by the institutional ethical committee board of Guangzhou Women and Children’s Medical Center (No.201924801).Data on all singleton live births  was grouped into seven intervals: 15–19, 20–23, 24–27, 28–31, 32–35, 36–39, and 40–44 years. Delivery years (period) were grouped into four 4-year categories . Ten 4-year maternal birth cohorts were obtained by subtracting age from period and labelled as the midpoint of the birth years . For example, those delivered during the period 2001–2004 at the age of 20–23 were born between 1978 and 1984, thus the midpoint, 1981, was used to represent their birth cohort.Gestational age was confirmed based on an ultrasound examination in the first or second trimester . When thPoisson regression models with robust variance were used to estimate the change per year of PTB incidence and 95% confidence intervals (CIs). We also examined the interaction effects between maternal delivery year and parity to test whether the change of PTB incidences among primipara and multipara differed over the 16-year period using Poisson regression model. Age-specific PTB incidences were plotted using heatmaps by maternal delivery period and birth cohort for both parity, respectively.age = period – cohort) of 3 time-related factors [The age-period-cohort (APC) analysis models were used to investigate the effects of maternal age, delivery year and birth year of mothers on the change trends of PTB incidence. The method described by Carstensen was used to solve the exact linear dependency  or very (28–31 weeks) preterm delivery, which is an important indicator of improvement of modern intensive care for the premature infant.The age-period-cohort models were performed separately by primiparas and multiparas, using the apc.fit function in the Epi package  in R (veP < 0.001). Before 2008, the incidence of PTB among multiparous mothers was consistently higher than that among primiparous mothers. After that, the incidences among these two groups became similar. Figure A total of 2,535,000 mothers with singleton live births were included in the final analysis, of which 1,565,992 (61.8%) were primiparous and 969,008 (38.2%) were multiparous. Figure Figure Supplementary Table 2 [see Additional file Figure Cohort and period effects reported as risk ratios of PTB are the curves in the middle and on the right of Fig. The risk ratios of preterm delivery in primiparous mothers remained stable across the study period when compared to the reference period of 2001–2004. For multiparous mothers, there was a slight decline in risk ratios of PTB in the period of 2001–2012  compared with the period of 2001–2004.When restricting to extremely or very PTB, the age and the cohort effects were similar to those for overall PTB. The period effects showed a V-shaped curve among both parity, where the nadir of risk ratios appeared in 2009–2012 . The findings were presented in Supplementary Fig. 1 and Supplementary Table 3 . However, other risk factors of PTB, such as health problems triggered by urbanization and increasing use of assisted reproductive technology, may counteract the effects of improvement of medical care services, which may partially explain the effects of periods of extremely or very PTB tended to be null in the more recent years , 29. In Our findings showed that mothers born in more recent era had a higher risk of PTB among primiparous mothers as well as among multiparous mothers who born before 1981. Mothers born in more recent birth cohort experience remarkable lifestyle change, increased environmental pollution, and higher stress due to rapid change of economy and society, which may pose profound impacts on women’s reproductive system –32. For We observed that the effects of maternal age or maternal birth cohorts on PTB differed by parity. Although the mechanisms are still not fully understood, it might be partly due to the difference in maternal health conditions, socio-economic background and psychological pressure and so on at each age group between primiparous and multiparous mothers. Further studies are warranted to determine which factors are relevant to our observed effects of maternal age and birth cohorts on PTB and how they might interact with each other.Although a large sample size included in the analysis enabled us to estimate robust results, several limitations should be considered in the study. Firstly, data on some explanatory variables, such as cigarette smoking, a known risk factor of PTB, were not available in the electronic surveillance database of birth registration; thus we were unable to elucidate the detailed mechanisms of observed maternal age and birth cohort on PTB in this study. However, it is worth noting that in China, the prevalence of cigarette smoking among pregnant women is lower than 1% , 36. SecFrom a public health perspective, this study suggests that young and advanced-age mothers have higher risk of PTB, and primiparous mothers at higher risk of PTB were younger than multiparous mothers in older age. Thus, prenatal care and interventions should be targeted at young and older pregnant women, particularly for primiparous mothers. Since the implementation of universal 2-child policy in January 2016, there has been a substantial rise in the number of advanced-age pregnant women and premature infants. Allocation of resources for reversing the rising trend of PTB and preventing and treating PTB-related complications in children are warranted. Besides, as Guangzhou is one of the most developed cities in China, our study will provide evidence for the future change of PTB in other developing regions.Our findings showed the PTB incidences had been increasing in the past 16 years in the Guangzhou, China and both maternal age and cohort effects contributed to these trends. With constant social-economic growth and implementation of universal 2-child policy in China, more attention on the impact of altered maternal age and parity on premature births and corresponding public education and public health policies is needed in the future.Additional file 1. Supplemental Tables 1–3 and Supplemental Figs. 1. Supplementary Table 1 Maternal and newborn characteristics by parity among singleton live births in. Guangzhou, China from 2001 to 2016. Supplementary Table 2 Analysis of deviance for Age-Period-Cohort models for preterm birth incidence, stratified by parity. Supplementary Table 3 Analysis of deviance for Age-Period-Cohort models for extremely or very preterm birth incidence, stratified by parity. Supplementary Fig. 1 Age-period-cohort influences on trends in extremely or very preterm birth by parity in Guangzhou, China, from 2001 to 2016


To investigate whether risks of stillbirth and neonatal death differ after fresh and frozen embryo transfer (fresh and frozen-ET) compared to singletons conceived without medical assistance.Population-based cohort.Data linkage between the nationwide Medical Birth Registries in Denmark (1994-2014), Norway and Sweden (1988-2015), and national quality registries and databases on assisted reproductive technology.4,590,853 singletons, including 78,642 conceived by fresh transfer and 18,084 by frozen-ET.NoneStillbirth  and neonatal death (live born with death 0-27 days postpartum).Overall, 17,123 (0.37%) singletons were stillborn and 7,685 (0.17%) died neonatally. Compared to singletons conceived without medical assistance, the odds of stillbirth were similar after fresh and frozen-ET, while odds of neonatal death were higher after fresh  and frozen-ET .Preterm birth  was more common after fresh (8.0%) and frozen-ET (6.6%) compared to singletons conceived without medical assistance (5.0%), and strongly associated with neonatal mortality across all conception methods. Within gestational age categories, risk of stillbirth and neonatal death was similar for all conception methods, except that singletons from fresh-ET had a higher risk of stillbirth during gestational week 22-27 .Overall risk of stillbirth was similar after fresh and frozen-ET compared to singletons conceived without medical assistance, whereas neonatal mortality was higher, possibly mediated by the higher risk of preterm birth when compared to singletons conceived without medical assistance. Our results gave no clear support for choosing one treatment over the other. From its experimental beginning, assisted reproductive technology (ART) has grown into a successful treatment with >9 million children born worldwide., 2 WhilePerinatal loss, whether stillbirth or neonatal death, is a traumatic outcome for expecting couples and often associated with preterm birth, congenital malformations, and placental complications.–11StudieFurther, the increasing use of frozen-ET highlights the need to differentiate between different types of ART when assessing risk of stillbirth and neonatal death, which could not be done in most previous studies., 19, 20 Singletons conceived after both fresh-ET and frozen-ET are at increased risk of adverse perinatal outcomes, including preterm birth,, 17, 18 In this study we compared the risk of stillbirth and neonatal death in singletons born after fresh-ET and frozen-ET to singletons born without medical assistance, in a large Nordic population of births during 1988-2015. We also estimated risk according to gestational age.This study is based on the Committee of Nordic ART and Safety (CoNARTaS) cohort which includes data on all births registered in the nationwide Medical Birth Registries in Denmark 1994-2014), Norway (1984-2015) and Sweden (1985-2015).-2014, No From 198Exposures were fresh or frozen embryo transfer. Pregnancies with no ART registration was considered as conceptions without medical assistance. Our main outcomes were stillbirth and neonatal death, as defined by the Medical Birth Registry in each country. Until April 2004 in Denmark and July 2008 in Sweden, stillbirths were defined as deliveries at ≥28+0 weeks’ gestation with fetal death before or during delivery, thereafter the definition was expanded to include deliveries ≥22+0 weeks. Norway registered stillbirths delivered at ≥22+0 weeks throughout the study period. Live births were registered at any gestational age throughout the study period in all countries. Neonatal death was defined as a liveborn who died 0-27 days after birth.In pregnancies conceived without medical assistanece, gestational age was estimated from first (Denmark) or second (Norway and Sweden) trimester ultrasound examination when available, otherwise last menstrual period was used. For ART pregnancies, gestational age was estimated from embryo transfer date in Sweden. In Denmark and Norway, gestational age was estimated from ultrasound examination, or transfer date if ultrasound data were missing. We categorized gestational age as 22-27 (extremely preterm), 28-31 (very preterm), 32-36 (moderate to late preterm), 37-41 (term), and 42-44 (post-term). was calculated as weight in kilograms divided by height in meters squared. Maternal smoking habits were registered from 1999 in Norway and during the entire study period in Denmark and Sweden and was categorized as any versus no smoking during pregnancy. The number of embryos transferred in ART-conceived pregnancies were recorded in all countries during the entire study period. Culture duration in days was recorded from 1994 in Denmark, 2011 in Norway and 1985 in Sweden, and categorized as day 2-3 (cleavage stage embryo) and 5-6 (blastocyst). Placental complications included placental abruption, placenta previa and hypertensive disorders in pregnancy as described previously.Causes of death were available from the Cause of Death Registry in each country for the liveborn population. Causes of neonatal death were categorized as recommended by the World Health Organization.The first delivery after frozen-ET was registered in 1988. Eligibility was defined as all singleton deliveries in 1988 or later, with known conception method and parity, by women who gave their first birth during the study period . AdditioFor analyses of stillbirth, we included stillborn and live born singletons ≥22 weeks from Norway throughout the study period, while from Denmark and Sweden we included stillborn and live born ≥28 weeks until April 2004 and July 2008 respectively, thereafter all stillborn and live born ≥22 weeks . In totaTo analyze neonatal death, we included only live born singletons with gestational age 22-44 weeks and excluded singletons with extreme  or missing birthweights  with 95% confidence intervals (CIs). To increase interpretability, we used post estimation commands to obtain risk differences. Potential confounders were factors previously shown to influence both stillbirth or neonatal death and the need for ART. Based on available information, we made the following adjustments: year of birth (continuous), country, maternal age (continuous), and parity.We examined the consistency of results by repeating analyses in samples with 1) recorded maternal weight, height, and smoking status, where we adjusted for BMI, height, and smoking status, 2) primiparous women only, 3) ART-conceptions restricted to single embryo transfer, and 4) ART-conceptions restricted to blastocyst transfer and pregnancies conceived without medical assistance restricted to birth years when blastocyst culture was recorded. For stillbirths, we repeated the analyses in a sample restricted to deliveries ≥28 weeks to examine the potential impact of different definitions of stillbirth. To facilitate comparison with other studies, we also analyzed early neonatal deaths, defined as live born children who died 0-6 days after birth, 32, 33.To investigate whether conception method modified the impact of gestational age on risk of stillbirth and neonatal death, we repeated analyses within categories of gestational age. For stillbirth, we used ‘fetuses at risk’ as the denominator , with logistic models for categorical estimates and survival analysis for continuous gestational age. For neonIn Denmark, ethical approval is not required for anonymised registry-based research. In Norway, ethical approval was given by the Regional Committee for Medical and Health Research Ethics . In Sweden, approval was obtained from the Ethical committee in Gothenburg .Compared to pregnancies conceived without medical assistance, pregnancies after fresh and frozen-ET were at higher risk of preterm birth . In all conception groups, preterm birth was substantially more common in cases of stillbirth and neonatal death. Malformations were also common among infants who died neonatally, with higher prevalence among singletons born without medical assistance, than after fresh-ET and frozen-ET. For stillbirths, the reported prevalence of malformations was low across all conception methods, possibly due to autopsy reports being completed after birth reports are sent to the Medical Birth Registries. Placental complications were more common after fresh and frozen-ET compared to pregnancies conceived without medical assistance. This pattern was similar but with higher incidence in pregnancies ending with stillbirth or neonatal death. The main causes of neonatal death reported to the Cause of Death Registry were malformations, maternal conditions and preterm birth, where the latter two were more common after ART conception .We found no clear association between conception method and risk of stillbirth, while neonatal mortality was higher after both fresh and frozen-ET compared to singletons born without medical assistance . AdjustmIn analyses according to gestational age, the absolute risk of stillbirth was highest in term (37-41 weeks) gestations, when most deliveries occurred . For sinCompared to singletons born without medical assistance, singletons conceived after fresh and frozen-ET had an overall similar risk of stillbirth, but a higher risk of neonatal death. Apart from a higher risk of stillbirth in pregnancies after fresh-ET in weeks 22-27, we found no clear differences in associations for fresh and frozen-ET. The higher risk of neonatal death after both fresh and frozen-ET might be attributed to a higher risk of preterm birth in ART pregnancies.The lack of association between conception method and risk of stillbirth in our study is in contrast to results from a population-based study from the Netherlands, where a nearly doubled risk of stillbirth was found for any ART  compared to pregnancies conceived without medical assistance. A meta-aOur results are consistent with the limited number of previous studies on conception method and neonatal mortality, showing higher neonatal mortality after any ART,, 19, 23 We are not aware of previous studies assessing whether pregnancies after fresh and frozen-ET are more vulnerable to stillbirth or neonatal death at specific gestational ages. An Australian study compared pregnancies after any ART  to pregnancies conceived without medical assistance and found lower perinatal mortality <32 weeks. However,In the early years of our study period, slow freeze was the standard method of cryopreservation but was gradually replaced by vitrification from around 2008. In parallel culture duration shifted from cleavage stage to blastocyst before embryo freezing. A comparison of singletons from slow-frozen cleavage stage embryos vs vitrified blastocysts in Denmark and Sweden showed no difference in perinatal or neonatal death, but with very limited precision. Our senWe had no data on endometrial preparation in frozen-ET. Previous studies indicate lower risk of hypertensive disorders in pregnancies with no endometrial preparation , but simiDespite the higher risk of adverse perinatal outcomes in ART pregnancies, including preterm birth, low birthweight, and placental complications as shown previously in this study population,, 29, 41 In the country specific estimations  we foundEarly in our study period, women with ART conceptions had more antenatal visits than women conceiving without medical assistance., 44 HoweFuture studies should investigate whether indicators of infertility may improve risk stratification of pregnancies beyond current guidelines.For infertile couples and clinicians, the similar associations for fresh-ET and frozen-ET do not give reason to prefer one method over the other to prevent stillbirth or neonatal death.To our knowledge this is the largest study so far of stillbirth and neonatal mortality after fresh and frozen-ET compared to singletons conceived without medical assistance, including an additional 51,000 ART singletons born 2008-2014/2015 compared to previous Nordic registry studies., 23 The The national identity number ensured reliable data linkage and reporting to the registries is mandatory in all participating countries. Data onBecause gestational age is an intermediate factor between ART-conception and neonatal death, interpretation of our analyses of neonatal death according to gestational age requires careful consideration. In termDespite including data from three countries, statistical power was limited. Estimates according to gestational age had low precision due to the stratification itself, but also because stillbirths often had missing data on other factors, including gestational age.It should be noted that neonatal death and stillbirth rates are low in all Nordic countries, even when compared to other high-income countries, 55, 56.Our results suggest that singletons conceived by fresh and frozen embryo transfer are not at higher overall risk of stillbirth compared with pregnancies conceived without medical conceptions, though singletons after fresh-ET may be at higher risk in gestational week 22-27. Both types of ART-conception carry a higher risk of neonatal death, possibly mediated by preterm birth. The similarity of results between fresh and frozen-ET treatment, indicate that for couples in need of ART, reassurance can be provided that a frozen embryo is unlikely to increase risk of stillbirth and neonatal mortality compared with fresh transfer (and vice versa).Supplementary materialSupplementary Figures


This research was conducted to analyze the elements and factors that link with newborn deaths at Neonatal Intensive Care Unit (NICU) of a public teaching hospital in Jordan.st of March, 2018 to 28th of February, 2019 at Princess Rahma Pediatric Hospital, Jordan.A retrospective study was conducted by reviewing the medical records of all the neonates admitted to the NICU over a one- year period from 1Overall, the medical records of 1247 neonates were included in this study. The common causes of admission were sepsis (27.3%), followed by respiratory distress syndrome (RDS) (24.9%) and asphyxia (13.1%). The majority of the admitted neonates survived (91.9%), and the overall mortality rate was 8.1%. According to the cause-specific death rate analysis, RDS was the most common cause of death rate (35.6%), followed by sepsis (27.7%). Logistic regression analysis results show that gestational age, weight of the baby at birth, and the quick clinical assessment (Apgar) within the first five minutes were the strongest predictors of neonatal mortality (P<0.05).Sepsis, RDS, and asphyxia were the leading causes of morbidity in neonates. These diseases were also responsible for a high rate of mortality. Understanding the cause of morbidity and mortality of neonates admitted at NICU is useful for prioritizing and planning health services, re-allocating resources, and improving the quality of care. The neonatal phase, which is the first 28 days of an infant’s life, is a vulnerable period due to many reversible severe illnesses. Low infant birth weight and premature babies are at a higher risk and are universally acknowledged as the ranking causes of morbidity and neonatal deaths.1According to the World Health Organization, of the 130 million newborns, four million will die during the neonatal period, and half neonatal deaths  occur within the first 24 hours of life.2The NICU must have highly sophisticated facilities and equipment to address critical cases, facilitate adjustment of the newborn to the extra-uterine life, and establish and maintain normal respiration of a high-risk newborn.4A remarkable decline in mortality rates during neonatal period for the past two decades is due to the advances of obstetric practice in term of medical screening and surveillance, and increased neonatal specialization. However, respiratory tract disorders, along with sepsis and other types of infection, are the major causes of neonatal morbidities and mortalities.5There is a paucity of studies that address neonatal morbidity and mortality as NICU admission patterns vary based on region and time.st of March, 2018 to 28th of February, 2019. This study was approved by the ethical committee of the hospital administration (IRB # 18-02-3135).This one-year retrospective study  was conducted in the NICU of Princess Rahma Pediatric Teaching Hospital, Irbid; Jordan from 1The hospital is considered as the main public pediatric teaching hospital in northern Jordan. The catchment area of the hospital is about two million persons. The NICU affiliated to the hospital is a referral unit in the region, and has a capacity of 32 incubators. The NICU has the following facilities: phototherapy, parenteral nutrition, exchange transfusion, artificial respirator, monitoring of carbon dioxide and oxygen level in the blood, oxygen gas supply system, bubble CPAP delivery system, and laboratory tests.Records of all admitted neonates were reviewed with respect to their medical information. The details were collected using a pretested, structured questionnaire prepared in English. The measured variable (survive or death) was the outcome. While gender of the neonate, gestational age, birth weight, Apgar score, place of delivery, mode of delivery, and length of hospital stay were the controlled variables. The cause of admission and the status at discharge were recorded based on the final diagnosis.The inclusion criteria of the study were the in-born and out-born neonates admitted to the NICU and diagnosed clinically. Neonates whose data were incomplete, who had ≥ two diagnoses, who were kept under observation, who were taken out of the hospital against medical advice, and who were referred to other hospitals for further medical interventions were excluded from the study. Training was provided regarding data collection techniques to familiarize the data collectors with the instrument.The data was examined using statistical software, i.e., SPSS . To evaluate the demographic data such as age, gender, race and ethnicity, descriptive statistics were used. The proportionate mortality rate (PMR) was calculated by dividing the proportion of cause-specific deaths by the number of deaths from all causes and was then multiplied by 100. The logistic regression was calculated to predict the association between characteristics of newborn at admission and the outcome at discharge. The crude odds ratio was scrutinized with a 95% confidence interval (CI), A p-value <0.05 was perceived to be statistically significant.Overall, 1247 neonates were admitted to the NICU during the study period; of these, 703 (56.4%) were male and 544 (43.6%) were female. The majority  were inborn (PRTH) and 151 (12.1%) were referred from other hospitals that have a low level of NICU care. Among those admitted, 776 (62.2%) were full term with the gestational age of ≥37 weeks; the remaining 471 (37.8%) were preterm with the gestational age <37 weeks. Most of the full-term neonates 576 (74.2%) had a normal weight (≥ 2500g) at time of admission, followed by 162 (20.9%) with low birth weight (1500–2499g), and remaining 38 (4.9%) were with very low birth weight (<1500). While in pre-term neonates, 247 (52.4%) were with low birth weight, 167 (35.5%) had a normal weight, and the remaining 57 (12.1%) had a very low birth weight. Regarding the Apgar score at 5 minute, most of the admitted full term neonates  scored 8-10 , followed by those  who scored 4-7  and the remaining  scored 0-3 . While the Apgar score of preterm neonates most of them  scored 4-7 , followed by  scored 8-10 , and the remaining  scored 0-3.The majority of the admitted neonates were delivered via caesarian-section , the remaining were delivered normally . The average length of hospital stay was 9.6 days; the majority of the admitted neonates stayed in the hospital for ≤7 days , and the remaining stayed for >7 days  .The most common causes of the NICU admission were neonatal sepsis , respiratory distress syndrome , and birth asphyxia . For sepsis cases, the most common isolated pathogen was Enterobacter 34 (40.5%), followed by Coagulase-Negative staphylococcus 20 (23.8%). The details are presented in Overall, 1147 (91.9%) neonates were discharged after improvement. However, the remaining 101 (8.1%) died. The major causes for mortality according to the PMR analysis were RDS (35.6%), followed by neonatal sepsis (27.7%) and neonatal asphyxia (24.8%). The details are present in p <0.05) (p = 0.001). Neonates with birth weight <1500 g were less likely to survive than those with birth weight ≥2500 g . Finally, neonates with the Apgar score at 5 minutes of 0–3  were less likely to survive than those with the score of 8–10  .The logistic regression model showed that gestational age, weight of the baby at birth and the quick clinical assessment (Apgar) performed within the first five minutes of birth were significantly related with neonatal survival state (p <0.05) . NeonateThis research was carried out to describe the factors which decisively affects the morbidity pattern, risk factors and undesirable outcomes, leading to neonatal deaths at NICU, a tertiary care public teaching hospital. In this study, the vast majority of admitted neonates (87.9%) were in-born and the rest were out-born. The outborns were referred from other public hospitals of north of Jordan because the respective NICU were fully occupied, or the neonates required a high level of intensive care. The high percentage of inborns indicates improved awareness of parents regarding birth in the hospital, and is consistent with the Jordan Ministry of Health strategies to reduce the neonatal mortality rate in Jordan.In the present study, the preterm neonates 37.8%) had a gestational age < 37 weeks at admissions, and the remaining 62.2% had full-term. Similar findings were reported in a study conducted in Ethiopia% had a g9Regarding the birth weight, most of the full term neonates 576 (74.2%) weighted ≥ 2500 g at time of admission, and the remaining 200 25.8%) were weighted ≤ 2500 g. While the majority of preterm neonates 304 (64.5%) were weighted ≤ 2500. The percentage of full term with ≤ 2500g (25.8%) is comparable with studies from Pakistan (37.7%),% were we11Most of the admitted neonates were delivered by caesarian-section (62.8%). Similarly, in a study conducted in Iran by Fallahi et al.,14In this study the average length of hospital stay was 9.6 days, and the majority stayed for ≤ seven days. An identical study was carried out in Nepal where the majority of admitted neonates stayed for 6-10 days.15The most common causes of admission to the NICU were neonatal sepsis (27.3%), followed by RDS (24.9%) and asphyxia (13.1%). This finding is more or less the same as it was observed in the study conducted by Kanodia et al.19The predominantly isolated pathogen in the study was Enterobacter, the other pathogens such as Coagulase–Negative Staphylococci, and Klebsiella were less common. A study on the Pakistani population, Escherechia Coli was the most common organism followed by Klebsiella, and among the gram-positive organisms, Staphylococcus Aurous was most frequent.20The death rate observed in our study (8.1%) is similar to the death rate observed in a research conducted by Manktelow et al.,23Logistic regression model predicts that gestational age, weight of the baby at birth, and Apgar score performed within the first five minutes of birth neonatal mortality. A study conducted in Ethiopia has the same findings.25This research was performed by studying the available records at hospital and could not address some more topics because of limitations. As it was a clinical based study that examined data from the medical records of neonates in a single health facility, the findings cannot be generalized.This study shows that neonatal sepsis, neonatal RDS, and perinatal asphyxia are leading grounds of morbidities in newborns, and are responsible for a high rate of mortality but the order is different. Understanding the cause of morbidity and mortality of neonates admitted at NICU is useful for prioritizing and planning health services, re-allocating resources, and improving the quality of care.