Sex differences in the prevalence of congenital anomalies: a population-based study

Genome-wide study of gene-by-sex interactions identifies risks for cleft palate

Structural birth defects affect 3-4% of all live births and, depending on the type, tend to manifest in a sex-biased manner. Orofacial clefts (OFCs) are the most common craniofacial structural birth defects and are often divided into cleft lip with or without cleft palate (CL/P) and cleft palate only (CP). Previous studies have found sex-specific risks for CL/P, but these risks have yet to be evaluated in CP. CL/P is more common in males and CP is more frequently observed in females, so we hypothesized there would also be sex-specific differences for CP. Using a trio-based cohort, we performed sex-stratified genome-wide association studies (GWAS) based on proband sex followed by a genome-wide gene-by-sex (GxS) interaction testing. There were 13 loci significant for GxS interactions, with the top finding in LTBP1 (RR=3.37 [2.04 - 5.56], p=1.93x10 -6 ). LTBP1 plays a role in regulating TGF-B bioavailability, and knockdown in both mice and zebrafish lead to craniofacial anomalies. Further, there is evidence for differential expression of LTBP1 between males and females in both mice and humans. Therefore, we tested the association between the imputed genetically regulated gene expression of genes with significant GxS interactions and the CP phenotype. We found significant association for LTBP1 in cell cultured fibroblasts in female probands (p=0.0013) but not in males. Taken altogether, we show there are sex-specific risks for CP that are otherwise undetectable in a combined sex cohort, and LTBP1 is a candidate risk gene, particularly in females.

Gastrulation-stage alcohol exposure induces similar rates of craniofacial malformations in male and female C57BL/6J mice

BACKGROUND

Prenatal alcohol exposure during gastrulation (embryonic day [E] 7 in mice, ~3rd week of human pregnancy) impairs eye, facial, and cortical development, recapitulating birth defects characteristic of Fetal Alcohol Syndrome (FAS). However, it is not known whether the prevalence or severity of craniofacial features associated with FAS is affected by biological sex.

METHODS

The current study administered either alcohol (2.9 g/kg, two i.p. doses, 4 hr apart) or vehicle to pregnant C57BL/6J females on E7, prior to gonadal sex differentiation, and assessed fetal morphology at E17.

RESULTS

Whereas sex did not affect fetal size in controls, alcohol-exposed females were smaller than both control females and alcohol-treated males. Alcohol exposure increased the incidence of eye defects to a similar degree in males and females. Together, these data suggest that females might be more sensitive to the general developmental effects of alcohol, but not effects specific to the craniofacies. Whole transcriptomic analysis of untreated E7 embryos found 214 differentially expressed genes in females vs. males, including those in pathways related to cilia and mitochondria, histone demethylase activity, and pluripotency.

CONCLUSION

Gastrulation-stage alcohol induces craniofacial malformations in male and female mouse fetuses at similar rates and severity, though growth deficits are more prevalent females. These findings support the investigation of biological sex as a contributing factor in prenatal alcohol studies.

Influence of fetal gender on overall perinatal outcome: a prospective observational study

BACKGROUND

Fetal gender is considered as one of significant predictors of pregnancy and perinatal outcome. The aim of this study is to assess impact of fetal gender on perinatal outcome.

METHODS

Present observational study was conducted in Obstetrics and Gynecology department of rural tertiary center of Northern India over one year (January-December 2018) on all randomly selected antenatal women at gestation ≥28 weeks, delivering by any route (cesarean/vaginal) and fulfilling inclusion criteria were enrolled. Immediately after delivery, neonatal birth weight was measured using table top beam weighing scale. Apgar scores at 1- and 5-minutes, Neonatal Intensive Care Unit admission, neonatal complications were assessed by pediatrician. Adverse perinatal outcome including neonatal morbidities (prematurity, neonatal intensive care unit admission, neonatal complications) and perinatal mortality were compared between two genders. Statistical analysis was done using SPSS 22 version software.

RESULTS

Of 3085 delivered neonates, 1450 (47%) were females, 1,633(52.9%) males and two (0.06%) had ambiguous genitalia, hence excluded. Mean values for neonatal birth weight for males was 2.77±0.540 kg and females 2.65±0.506 kg (P=0.0000). One- and 5-minute Apgar scores for male neonate were 6.81±1.565, 8.51±1.841 and for females 6.98±1.184, 8.70±1.383, respectively (P=0.001). NICU admission rate, need for oxygen and intubation, complications were significantly higher for male neonates (P<0.05) whereas females had higher incidence of intra-uterine growth restriction (P=0.000). Intra-uterine deaths were also more common with male gender (P=0.007). No significant difference was observed between two genders in relation to gestation at birth (P>0.05).

CONCLUSIONS

Male neonates had higher birth weight, but adverse perinatal outcome as compared to females.

Analysis of pathogenic variants in 605 Chinese children with non-syndromic cardiac conotruncal defects based on targeted sequencing

OBJECTIVE

Deleterious genetic variants comprise one cause of cardiac conotruncal defects (CTDs). Genes associated with CTDs are gradually being identified. In the present study, we aimed to explore the profile of genetic variants of CTD-associated genes in Chinese patients with non-syndromic CTDs.

METHODS

Thirty-nine CTD-related genes were selected after reviewing published articles in NCBI, HGMD, OMIM, and HPO. In total, 605 patients with non-syndromic CTDs and 300 healthy controls, all of Han ethnicity, were recruited. High-throughput targeted sequencing was used to detect genetic variants in the protein-coding regions of genes. We performed rigorous variant-level filtrations to identify potentially damaging variants (Dvars) using prediction programs including CADD, SIFT, PolyPhen-2, and MutationTaster.

RESULT

Dvars were detected in 66.7% (26/39) of the targeted CTD-associated genes. In total, 11.07% (67/605) of patients with non-syndromic CTDs were found to carry one or more Dvars in targeted CTD-associated genes. Dvars in FOXH1, TBX2, NFATC1, FOXC2, and FOXC1 were common in the CTD cohort (1.5% [9/605], 1.2% [7/605], 1.2% [7/605], 1% [6/605], and 0.5% [3/605], respectively).

CONCLUSION

Targeted exon sequencing is a cost-effective approach for the genetic diagnosis of CTDs. Our findings contribute to an understanding of the genetic architecture of non-syndromic CTDs.

Sex chromosome mechanisms in cardiac development and disease

Many human diseases, including cardiovascular disease, show differences between men and women in pathology and treatment outcomes. In the case of cardiac disease, sex differences are exemplified by differences in the frequency of specific types of congenital and adult-onset heart disease. Clinical studies have suggested that gonadal hormones are a factor in sex bias. However, recent research has shown that gene and protein networks under non-hormonal control also account for cardiac sex differences. In this review, we describe the sex chromosome pathways that lead to sex differences in the development and function of the heart and highlight how these findings affect future care and treatment of cardiac disease.

Multiple subtypes of coxsackievirus group B can cause congenital heart disease

BACKGROUND

Different serotypes of coxsackievirus B (CVB), which is the most common cause of viral myocarditis, target cardiomyocytes through Coxsackie and Adenovirus Receptor and Decay-Accelerating Factor. Both receptors are expressed in the fetal heart. We hypothesized that infection with different serotypes of CVB during early pregnancy plays a role in pathogenesis of congenital heart defect (CHD).

METHODS

In this study, we use a murine model to infect with CVB1, CVB4, and combination of CVB3 + CVB4 during a critical period in gestation. We examined offspring of pregnant mice for fetal death and heart defects following viral infection.

RESULT

Fetuses from uninfected control dams showed normal heart development, while maternal CVB infection precipitates CHD: majorly ventricular septal defects (VSD) and non-compaction of ventricular myocardium (NC), with some infrequent cases of double outlet right ventricle, left ventricle wall rupture, right ventricle hypertrophy, and thickened/dysplastic semilunar valves. Infection of pregnant dams with CVB1 leads to 44% VSD and 41.2% NC cases, while with CVB4 leads to 31.7% VSD and 13.3% NC cases. Co-infection with CVB3 + CVB4 increases fetal pathology to 51.3% VSD and 41% NC cases. Infection can also result in fetal death, with higher incidences with CVB3 + CVB4 with 46.2% cases, compared to 33.3% by CVB1 and 21.7% by CVB4. Male fetuses were more susceptible to all phenotypes.

CONCLUSION

Our report shows that prenatal CVB infections can lead to pathogenesis of certain heart defects in mouse model, particularly exacerbated with co-infections. This data confirms a link between prenatal CVB infection and CHD development and highlights it is not unique to just one serotype of CVB.

The Prevalence of Congenital Anomalies of the Airway or Lung in Infants with Hypoplastic Left Heart Syndrome and Differences in Midterm Outcomes: A National Pediatric Cardiology Quality Improvement Collaborative Registry Analysis

Infants with single ventricle physiology and congenital anomalies of the airway and/or lung are potentially poor candidates for staged palliation. The prevalence and midterm outcomes for patients with anomalies of the airway or lung with hypoplastic left heart syndrome are unknown. We performed an analysis of data in infants with hypoplastic left heart syndrome from the National Pediatric Cardiology Quality Improvement Collaborative registry. The prevalence of congenital anomalies of the airway or lung in the registry was determined. Clinical characteristics and midterm outcomes were compared between infants with hypoplastic left heart syndrome with and without anomalies of the airway or lung. Fifty-seven (2.3%) of 2467 infants with hypoplastic left heart syndrome enrolled in the registry had congenital airway or lung anomalies. Infants congenital anomalies of the airway or lung had significantly lower transplant-free survival at 1 year (49.5 vs 77.2%, p < 0.001). Infants with airway or lung anomalies had longer combined hospital length of stay for stage 1 and stage 2 palliation (102 vs 65.1 days, p < 0.001) and underwent more major procedures (2.04 vs 0.93 procedures, p < 0.001) than those without. There was no difference in the number of interstage readmissions (1.85 vs 1.89, p = 0.87) or need for non-oral feeding supplementation (71.4 vs 54.5%, p = 0.12) between groups. Infants enrolled in the National Pediatric Cardiology Quality Improvement Collaborative registry with hypoplastic left heart syndrome and anomalies of the airway or lung have increased morbidity and mortality at 1 year compared to those with hypoplastic left heart syndrome alone.

Gender bias in fetal malformations: A cross-sectional study in Asian populations

OBJECTIVES

The aim of this study was to detect any gender bias in fetal malformation cases.

DESIGN

This study was a cross-sectional, quantitative survey.

SUBJECTS

Overall, 1,661 Asian fetal malformation cases involving induced abortions in the obstetrics department of the first Affiliated Hospital of Zhengzhou University from 2012 to 2021 were included.

MAIN OUTCOME MEASURES

Measurements of ultrasound detectable structural malformations were classified into 13 subtypes. Karyotyping, single nucleotide polymorphism (SNP) array, or sequencing diagnosis of these fetus was also included in the outcome measures.

RESULTS

The sex ratio (male/female) of all malformation types was 1.446. Cardiopulmonary had the highest proportion of all malformation types with 28%. Diaphragmatic hernia, omphalocele, gastroschisis, nuchal translucency (NT), and Multy malformations had significantly higher proportions of males (p < 0.05). Digestive system malformations had a significantly higher proportion of females (p < 0.05). Maternal age was associated with genetic factors (r = 0.953, p < 0.001) and inversely associated with brain malformations (r = -0.570, p = 0.002). More males were found with trisomy 21, trisomy 18, and monogenetic diseases, while duplications, deletions, and uniparental disomy (UPD) had similar sex ratios between males and females, but not statistically significant.

CONCLUSION

Sex differences are common with fetal malformations, with higher proportions of males. Genetic testing has been proposed to account for these differences.

Epidemiologic and clinical characteristics of selected congenital anomalies at the largest Bosnian pediatric surgery tertiary center

Congenital anomalies (CA) are any abnormality present at birth, either structural or functional, that may potentially affect an infant's health, development, and/or survival. There is a paucity of studies on clinical characteristics and outcomes of CA in Bosnia and Herzegovina, mainly due to the lack of a nationwide congenital malformations monitoring system. A 5-year hospital-based study was conducted to determine the prevalence at birth and clinical characteristics of selected major CA in Sarajevo Canton, Bosnia and Herzegovina. Ninety-one CA were observed from 2012 to 2016 (the overall prevalence was 39.6 cases/10,000 live births). The mean age of neonates at diagnosis was 3 days. The gastrointestinal tract was the most commonly affected system (76.9%), with esophageal atresia (EA) being the most frequent (17.6% of all CA). Major CA were more prevalent among preterm infants than term infants (P = .001), particularly in males (61.5% vs. 38.5%; P = .028; M:F ratio was 1.59). Multiple CA were seen in 37.4% of neonates. The overall mortality rate of neonates was 11%, and the median length of hospital stay was 19.8 days. Our study revealed the distribution and clinical patterns of common major CA in the largest tertiary care facility in Bosnia and Herzegovina. It also confirmed a relatively high mortality rate, which requires further efforts to improve the quality of neonatal care in the country.

Sex differences in childhood cancer risk among children with major birth defects: a Nordic population-based nested case-control study

BACKGROUND

Childhood cancer is more common among children with birth defects, suggesting a common aetiology. Whether this association differs by sex is unclear.

METHODS

We performed a population-based nested case-control study using nationwide health registries in four Nordic countries. We included 21 898 cancer cases (0-19 years) and 218 980 matched population controls, born 1967-2014. Associations between childhood cancer and major birth defects were calculated as odds ratios (ORs) with 95% confidence intervals (CIs) using logistic regression models. Effect modification was evaluated using a counterfactual framework to estimate confidence intervals and P-values for the natural indirect effects.

RESULTS

Birth defects were present for 5.1% (1117/21 898) of childhood cancer cases and 2.2% (4873/218 980) of controls; OR of cancer was higher for chromosomal (OR = 10, 95% CI = 8.6-12) than for non-chromosomal defects (OR = 1.9, 95% CI = 1.8-2.1), strongest between genetic syndromes/microdeletion and renal tumours, Down syndrome and leukaemia, and nervous system defects and central nervous system tumours. The association between birth defects and cancer was stronger among females (OR = 2.8, 95% CI = 2.6-3.1) than males (OR = 2.1, 95% CI = 1.9-2.2, Pinteraction <0.001). Male sex was an independent risk factor for childhood cancer, but very little of the overall association between sex and childhood cancer was mediated through birth defects (4.8%, PNIE <0.001), although more at younger ages (10% below years and 28% below 1 year).

CONCLUSIONS

The birth defect-cancer associations were generally stronger among females than males. Birth defects did not act as a strong mediator for the modest differences in childhood cancer risk by sex, suggesting that other biological pathways are involved.

Trends of Hospital Admissions Due to Congenital Anomalies in England and Wales between 1999 and 2019: An Ecological Study

Objectives: To investigate the trends in congenital anomalies-related hospital admissions in England and Wales. Methods: This was an ecological study that was conducted using hospital admission data taken from the Hospital Episode Statistics database in England and the Patient Episode Database for Wales. Congenital malformations, deformations and chromosomal abnormalities hospital admissions data were extracted for the period between April 1999 and March 2019. Results: Hospital admission rate increased by 4.9% [from 198.74 (95% CI 197.53–199.94) in 1999 to 208.55 (95% CI 207.39–209.71) in 2019 per 100,000 persons, trend test, p < 0.01]. The most common hospital admissions causes were congenital malformations of the circulatory system, the musculoskeletal system, genital organs, and the digestive system. The most notable increase in hospital admissions rate was observed in congenital malformations of the respiratory system (1.01-fold). The age group below 15 years accounted for 75.1% of the total number of hospital admissions. Males contributed to 57.5% of the whole number of hospital admission. Hospital admission rate between females was increased by 6.4% [from 162.63 (95% CI 161.10–164.16) in 1999 to 173.05 (95% CI 171.57–174.54) in 2019 per 100,000 persons]. Hospital admission rate between males was increased by 3.4% [from 236.61 (95% CI 234.72–238.50) in 1999 to 244.70 (95% CI 242.92–246.49) in 2019 per 100,000 persons]. Conclusions: Males had a higher percentage of hospitalisation compared to females. Further studies to investigate the factors associated with higher hospitalisation rate among males are needed.

Evaluation and Risk Assessment of Congenital Anomalies in Neonates

Congenital anomalies (CA) are a large heterogeneous group of disorders of abnormal morphogenesis or biochemistry which present at birth and carry widely variable implications for morbidity and mortality. They are the leading cause of infant mortality in the USA, with an incidence of 3-4% of all births. CA are the fourth leading cause of neonatal mortality worldwide, with an estimated 295,000 deaths annually. The enormous variability in the clinical presentation in terms of severity, time of occurrence, course, complications, management, and outcomes makes the evaluation of CA complicated, highly specific, and individualized. The anomalies can impart tremendous physical, social, and emotional distress on the patient with massive emotional, social, financial, and medical implications for the family and society. The diagnosis may remain elusive despite rigorous, elaborate, and extensive investigations in many cases. While the enormous strides in genetic testing and gene modification therapy have an encouraging impact on the diagnosis and treatment, the risk assessment of recurrence in the family and population of CA remains obscure in most cases due to the lack of information and referable evidence.

Isolated fetal neural tube defects associate with increased risk of placental pathology: Evidence from the Collaborative Perinatal Project

INTRODUCTION

Neural tube defects (NTDs) are amongst the most common congenital anomalies and are associated with significant postnatal morbidity, but also with a higher incidence of low birthweight and fetal growth restriction. Despite the placenta being a critical determinant of fetal growth, placental development has not been extensively studied in fetuses with NTDs.

METHODS

We performed a matched case-cohort study using data from the Collaborative Perinatal Project to assess the risk of placental pathology in pregnancies with an isolated fetal NTD (cases; n = 74) compared to those without any congenital anomalies (controls; n = 148). We hypothesised that cases would be at an increased risk of placental pathology compared to controls. Data were analysed using adjusted generalized linear and nominal logistic regression models. Results are presented as adjusted β or adjusted odds ratio (aOR; 95% confidence interval).

RESULTS

Cases had lower placental weight (β = -22.2 g [-37.8 to -6.6]), surface area (β = -9.6 cm² [-18.3 to -1.0]) and birth length z-scores (β = -0.4 [-0.7 to -0.001]) compared to controls. Cases were more likely to have a single umbilical artery (vs. two; 6 [8.1%] vs. 1 [0.7%]; aOR = 301 [52.6-1726]), placental hypermaturity (9 [12.2%] vs. 5 [3.4%]; aOR = 6.8 [3.1-14.7]), many (vs. few) Hofbauer cells (9 [12.2%] vs. 7 [4.7%]; aOR = 3.02 [1.2-7.3]), and stromal fibrosis (9 [12.2%] vs. 10 [6.8%]; aOR = 3.0 [1.4-6.3]) in placental terminal villi compared to controls.

CONCLUSIONS

Fetuses with isolated NTDs may be at increased risk of placental pathology, which could be contributing to poor fetal growth in these pregnancies and subsequent postnatal morbidities.

Night shift work undertaken by women and fertility treatment interact to increase prevalence of urogenital anomalies in children

OBJECTIVE

To investigate the role of maternal night shift work in occurrence of urogenital anomalies in offspring, considering a possible interaction with mode of conception.

METHODS

A population-based cohort comprising births in South Australia (1986-2002) was produced via linkage of fertility clinic records, perinatal and birth defects data. This study concerned first births to women in paid employment (n=98 103). Potential exposure to night shift was imputed by applying a job-exposure matrix to recorded occupation. Associations were examined using logistic regression, first for nurses and other night shift workers separately, then combined. An interaction term for night shift work and mode of conception was included in all models, while adjusting for covariates.

RESULTS

Associations were similar for nurses and other night shift workers, although only statistically significant for the former when considered separately. A multiplicative interaction was supported: for natural conceptions, maternal night shift work was not associated with offspring urogenital anomalies (OR=0.99, 95% CI 0.84 to 1.15); where a birth arose from fertility treatment, urogenital anomalies were significantly higher among births to all night shift workers compared with day workers (OR=2.07, 95% CI 1.20 to 3.55). This was not due to differences in the type of fertility treatment received.

CONCLUSIONS

Women in occupations that probably involved night shift did not have offspring with increased prevalence of urogenital anomalies if they conceived naturally. When night shift workers conceived with fertility treatment, the prevalence of urogenital anomalies was elevated. Possibly these women had the greatest exposure to night shift work, or least tolerance for this work schedule, or heightened sensitivity to hormonal aspects of fertility treatment.

Coxsackievirus B3 Infection Early in Pregnancy Induces Congenital Heart Defects Through Suppression of Fetal Cardiomyocyte Proliferation

Background Coxsackievirus B (CVB) is the most common cause of viral myocarditis. It targets cardiomyocytes through coxsackie and adenovirus receptor, which is highly expressed in the fetal heart. We hypothesized CVB3 can precipitate congenital heart defects when fetal infection occurs during critical window of gestation. Methods and Results We infected C57Bl/6 pregnant mice with CVB3 during time points in early gestation (embryonic day [E] 5, E7, E9, and E11). We used different viral titers to examine possible dose-response relationship and assessed viral loads in various fetal organs. Provided viral exposure occurred between E7 and E9, we observed characteristic features of ventricular septal defect (33.6%), abnormal myocardial architecture resembling noncompaction (23.5%), and double-outlet right ventricle (4.4%) among 209 viable fetuses examined. We observed a direct relationship between viral titers and severity of congenital heart defects, with apparent predominance among female fetuses. Infected dams remained healthy; we did not observe any maternal heart or placental injury suggestive of direct viral effects on developing heart as likely cause of congenital heart defects. We examined signaling pathways in CVB3-exposed hearts using RNA sequencing, Kyoto Encyclopedia of Genes and Genomes enrichment analysis, and immunohistochemistry. Signaling proteins of the Hippo, tight junction, transforming growth factor-β1, and extracellular matrix proteins were the most highly enriched in CVB3-infected fetuses with ventricular septal defects. Moreover, cardiomyocyte proliferation was 50% lower in fetuses with ventricular septal defects compared with uninfected controls. Conclusions We conclude prenatal CVB3 infection induces congenital heart defects. Alterations in myocardial proliferate capacity and consequent changes in cardiac architecture and trabeculation appear to account for most of observed phenotypes.

Prevalence and risk factors of radial ray deficiencies: A population-based case-control study

Radial ray deficiency is the most common congenital deficiency of the upper limb. The aim of our study was to investigate maternal risk factors for radial ray deficiencies. We conducted a nationwide population-based case-control study using national registers. All cases with a radial ray deficiency born between 1996 and 2008 were included in the study and compared with five controls without limb deficiency. In total, 115 (10 isolated, 18 with multiple congenital anomalies, and 87 syndromic) cases with radial ray deficiencies were identified and compared with 575 matched controls. The total prevalence in Finland was 1.22 per 10,000 births. No significant risk factors were observed for nonsyndromic cases. In the syndromic group, advanced maternal age (≥35 years) increased the risk of radial aplasia (aOR 2.45, 95% CI 1.37-4.36), and a similar association was observed with multiple pregnancy (aOR 2.97, 1.16-7.62) and male sex (aOR 1.96, 1.18-3.25). Valproic acid was also a risk factor (p = .002). In conclusion, novel associations in the syndromic group of advanced maternal age and multiple pregnancy and increased risk of radial ray deficiencies were observed. Also, early reports on increased risk of RRD associated with valproate and male sex were supported by our results.

Prevalence of structural birth defects among infants with Down syndrome, 2013-2017: A US population-based study

BACKGROUND

Down syndrome is the most common chromosomal disorder at birth and is often accompanied by structural birth defects. Current data on major structural defects in this population are limited.

METHODS

States and territorial population-based surveillance programs submitted data on identified cases of Down syndrome and identified structural birth defects during 2013-2017. We estimated prevalence by program type and maternal and infant characteristics. Among programs with active case ascertainment, we estimated the prevalence of birth defects by organ system and for specific defects by maternal age (<35, ≥35) and infant sex.

RESULTS

We identified 13,376 cases of Down syndrome. Prevalence among all programs was 12.7 per 10,000 live births. Among these children, 75% had at least one reported co-occurring birth defect diagnosis code. Among 6,210 cases identified by active programs, 66% had a cardiovascular defect with septal defects being the most common: atrial (32.5%), ventricular (20.6%), and atrioventricular (17.4%). Defect prevalence differed by infant sex more frequently than by maternal age. For example, atrioventricular septal defects were more common in female children (20.1% vs. 15.1%) while limb deficiencies were more prevalent in male children (0.4% vs. 0.1%).

CONCLUSIONS

Our study provides updated prevalence estimates for structural defects, including rare defects, among children with Down syndrome using one of the largest and most recent cohorts to date. These data may aid clinical care and surveillance.

Prevalence and pattern of birth defects in the two tertiary hospitals in Enugu, South East Nigeria: A hospital-based observational study

BACKGROUND

Birth defects have medical, surgical and aesthetic consequences. The impact of birth defects is particularly severe in low-income countries where health-care resources are limited.

AIMS AND OBJECTIVES

The aim of this study was to determine the prevalence and types of birth defects in live newborns delivered at the two tertiary hospitals in Enugu, South East Nigeria.

MATERIALS AND METHODS

This was a hospital-based observational study carried out on neonates delivered in the maternity units of the University of Nigeria Teaching Hospital Ituku/Ozalla and Enugu State University Teaching Hospital Parklane, Enugu during the periods of January 2015 and December 2018. All the live-born babies born in the two hospitals during this period were recruited into the study. The neonates were examined by a paediatrician for the presence of birth defects. The birth defects were classified according to the system involved and also into major and minor.

RESULTS

During the study period, 9492 babies were born, of which 166 had birth defects, which gave a prevalence of 1.75%. The predominant system affected by birth defects was the musculoskeletal system (45.2%) followed by the central nervous system (34.9%), urogenital system (10.8%) and gastrointestinal tract (9%). 13 (7.8%) patients had their birth defects diagnosed prenatally during the maternal ultrasound scan. Fifteen (9%) and 13 (7.8%) mothers of the neonates who had birth defects were diabetics and hypertensives, respectively. Most of the neonates were delivered vaginally.

CONCLUSION

Birth defects are not uncommon. This study showed a prevalence of 1.75% in the two tertiary hospitals in Enugu, South East Nigeria. The most commonly affected system was the musculoskeletal system.

Influence of fetal sex on perinatal outcomes in women with gestational diabetes mellitus

BACKGROUND

Fetal sex has recently been considered to be related to maternal glucose homeostasis and perinatal outcomes during pregnancy. Here, we investigated the effects of fetal sex on the perinatal outcomes of pregnancies with normal glucose tolerance (NGT) and gestational diabetes mellitus (GDM).

METHODS

This was a retrospective cohort study of 1292 women with NGT and 1155 women with GDM. Pregnant women were divided into four groups according to the maternal glucose level and fetal sex. Logistic regression was used to evaluate the risks for adverse perinatal outcomes among NGT-males, NGT-females, GDM-males and GDM-females.

RESULTS

NGT-males had higher risks for macrosomia and large for gestational age (LGA) than NGT-females with an odds ratio (OR) of 1.9 (95% CI 1.2-2.9). Additionally, GDM-males had higher risks for neonatal infection (OR, 3.0; 95% CI, 1.3-6.9), acute respiratory disorders (OR, 3.9; 95% CI, 1.1-13.7) and abnormal neonatal central nervous system development (OR, 3.1; 95% CI, 1.1-8.4) than GDM-females. Furthermore, there was a significantly higher risk for newborn infection (OR, 8.5; 95% CI, 1.1-66.8) in the GDM-male group than in the GDM-female group with a glycosylated hemoglobin A1c (HbA1c) level ≥5.5% in the late trimester of pregnancy, which was not observed with an HbA1c level of <5.5%.

CONCLUSIONS

Male fetuses have worse perinatal outcomes than female fetuses, and the difference is more pronounced in GDM pregnancies. More postpartum care is needed for male fetuses, especially in GDM pregnancies with substandard glycemic control.

p53 Mutant p53N236S Induces Neural Tube Defects in Female Embryos

The p53 is one of the most important tumor suppressors through surveillance of DNA damages and abnormal proliferation signals, and activation the cell cycle arrest and apoptosis in response to stress. However, the mutation of p53 is known to be oncogenic by both loss of function in inhibiting cell cycle progress and gain of function in promoting abnormal proliferation. In the present study, we have established a knock in mouse model containing an Asn-to-Ser substitution at p53 amino acid 236 by homologous recombination (p53N236S). Other than tumorigenesis phenotype, we found that p53^S/S mice displayed female-specific phenotype of open neural tube in brain (exencephaly) and spinal cord (spina bifida). The occurrence rate for embryonic exencephaly is 68.5% in female p53^S/S mice, which is much more than that of in p53^-/- mice (37.1%) in the same genetic background. Further study found that p53^N236S mutation increased neuronal proliferation and decreased neuronal differentiation and apoptosis. To rescue the phenotype, we inhibited cell proliferation by crossing Wrn^-/- mice with p53^S/S mice. The occurrence of NTDs in p53^S/S Wrn^-/- mice was 35.2%, thus suggesting that the inhibition of cell proliferation through a Wrn defect partially rescued the exencephaly phenotype in p53^S/S mice. We also report that p53S decreased expression of UTX at mRNA and protein level via increasing Xist transcript, result in high female-specific H3K27me3 expression and repressed Mash1 transcription, which facilitating abnormal proliferation, differentiation, and apoptosis, result in the mis-regulation of neurodevelopment and neural tube defects (NTDs).

Pattern and risk factors of congenital anomalies in a pediatric university hospital, Alexandria, Egypt

Background

Congenital anomalies (CAs) are structural, functional, or metabolic anomalies that originate during intrauterine life and can interfere with the body functions. In Egypt, the prevalence of CAs is increasing. The study aimed to estimate the frequency, describe the types, and identify the possible risk factors of CAs among infants attending the Pediatric University Hospital, Alexandria, Egypt.

Methods

A retrospective case series and a case-control study were conducted. Patients’ records for the years 2010–2015 were reviewed, and a sample of 200 infants (100 cases and 100 controls) was taken from infants presented to Pediatrics, Pediatric Surgery, and Genetics Clinics of the hospital. Data were collected using a record review checklist and a predesigned interviewing questionnaire.

Results

The study revealed that congenital anomalies of the digestive system (38.0%), musculoskeletal system (32.9%), and circulatory system (11.0%) were the most common types of CAs. Males were more affected with CAs than females (63% versus 37%). The major risk factors for CAs were old-aged parents, complications during pregnancy, unprescribed medications and excessive vitamin A intake during pregnancy, exposure to chemicals and pesticides during pregnancy, and living near mobile strengthening stations.

Conclusion

Congenital malformations of the digestive, musculoskeletal, and circulatory systems were the most common types of CAs in the Pediatric Hospital. To prevent CAs, there is a need to restrict the prescription of medications that may have a teratogenic effect.

Sex differences in the prevalence of neural tube defects and preventive effects of folic acid (FA) supplementation among five counties in northern China: results from a population-based birth defect surveillance programme

OBJECTIVES

Sex differences in prevalence of neural tube defects (NTDs) have previously been recognised; however, the different susceptibility of men and women have not been examined in relation to the effects of folic acid (FA) supplementation. We hypothesised that FA may have a disproportionate effect that alters the sex-specific prevalence of NTDs.

SETTING

Data from two time points, before (2003-2004) and after (2011-2016) the start of the supplementation programme, were obtained from a population-based birth defect surveillance programme among five counties in northern China. All live births (28 or more complete gestational weeks), all stillbirths of at least 20 weeks' gestational age and pregnancy terminations at any gestational age following the prenatal diagnosis of NTDs were included.

PARTICIPANTS

A total of 25 249 and 83 996 births before and after the programme were included respectively.

PRIMARY AND SECONDARY OUTCOME MEASURES

The prevalence of NTDs by sex and subtype, Male:female rate ratios and their 95% CI were calculated.

RESULTS

Overall, NTDs were less prevalent among men than among women (rate ratio (RR) 0.92; 95% CI 0.90 to 0.94), so was anencephaly (RR 0.77; 95% CI 0.73 to 0.81) and encephalocele (RR 0.75; 95% CI 0.61 to 0.92), while spina bifida showed a male predominance (RR 1.10; 95% CI 1.05 to 1.15). The overall prevalence of NTDs decreased by 78/10 000 in men and 108.7/10 000 in women from 2003 to 2004 to 2011 to 2016. There was a significant sex difference in the magnitude of reduction, being greater in women than men, particularly for anencephaly.

CONCLUSIONS

The prevalence of NTDs decreased in both sexes after the implementation of a massive FA supplementation programme. While female predominance was observed in open NTDs and total NTDs, they also had a greater rate of decrease in NTDs after the supplementation programme.

Nongenetic risk factors for holoprosencephaly: An updated review of the epidemiologic literature

Holoprosencephaly (HPE) is a major structural birth defect of the brain that occurs in approximately 1 in 10,000 live births. Although some genetic causes of HPE are known, a substantial proportion of cases have an unknown etiology. Due to the low birth prevalence and rarity of exposure to many potential risk factors for HPE, few epidemiologic studies have had sufficient sample size to examine risk factors. A 2010 review of the literature identified several risk factors that had been consistently identified as occurring more frequently among cases of HPE, including maternal diabetes, twinning, and a predominance of females, while also identifying a number of potential risk factors that had been less widely studied. In this article, we summarize a systematic literature review conducted to update the evidence for nongenetic risk factors for HPE.

Cohort Variation in Selection During Pregnancy and Risk of Selected Birth Defects Among Males

BACKGROUND

The literature theorizes, but does not test, that variation over time in selective loss in utero affects the observed count of live-born birth defects cases. We test the hypothesis that the risk of birth defects among live-born males varies inversely with the strength of selection against males in utero.

METHODS

We identified a subset of six birth defect phenotypes among males from the California Birth Defects Monitoring Program, an active surveillance system for over 490,000 male singletons born in eight California counties from 1986 to 2004. We assigned each birth defect case infant to a monthly conception cohort at risk of selection in utero. We used the monthly sex ratio at birth (M:F), derived from each conception cohort, as the indicator of selection against males. We analyzed the odds ratio of birth defects with both individual-level logistic regression and aggregate time-series methods.

RESULTS

Consistent with selection in utero, male infants from conception cohorts with low outlying sex ratios (i.e., stronger selectivity) exhibit fewer than expected birth defects (adjusted odds ratio [OR] = 0.86; 95% confidence interval [CI] = 0.76, 0.98). Aggregate time-series tests also yield similar findings (OR = 0.81; 95% CI = 0.71, 0.90).

CONCLUSIONS

Our findings among males indicate that variation in the strength of selectivity in utero accounts for a portion of observed cohort differences in morbidity due to birth defects. These findings suggest that "revealed prevalence" of morbidity across birth cohorts varies, at least in part, from selective loss in utero. See video abstract at, http://links.lww.com/EDE/B209.

Incidence of congenital diaphragmatic hernia in Olmsted County, Minnesota: a population-based study

OBJECTIVE

The rate of congenital diaphragmatic hernia (CDH) varies, but most reports estimate the incidence to be less than three per 10,000 births. Our objective was to document the incidence of CDH in a geographically well-defined population using available resources for highly accurate incident case ascertainment.

METHODS

We ascertained CDH cases in Olmsted County, Minnesota, United States of America, from 1981 through 2014 using resources of the Rochester Epidemiology Project. Overall and sex-specific incidence rates were calculated, and hospital survival was assessed.

RESULTS

A total of 26 incident CDH cases were identified; the overall incidence of 3.6 (95% CI, 2.2-5.0) per 10,000 did not differ significantly over the 34-year study period (p = .28). The estimated incidence was 4.3 (95% CI, 2.2-6.5) for male infants and 2.9 (95% CI, 1.1-4.6) for female infants. The percentage of cases diagnosed prenatally was 33% from 1981 through 2000 and 50% from 2001 through 2014. The rate of survival to discharge in the two periods was 50% and 88%.

CONCLUSION

The incidence of CDH in Olmsted County exceeds the majority of published rates, which most likely can be attributed to our comprehensive case ascertainment.

Multigenerational analysis of sex-specific phenotypic differences at midgestation caused by abnormal folate metabolism

The exposure to adverse environmental conditions (e.g. poor nutrition) may lead to increased disease risk in an individual and their descendants. In some cases, the results may be sexually dimorphic. A range of phenotypes has been associated with deficiency in or defective metabolism of the vitamin folate. However, the molecular mechanism linking folate metabolism to development is still not well defined nor is it clear whether phenotypes are sex-specific. The enzyme methionine synthase reductase (MTRR) is required for the progression of folate metabolism and the utilization of methyl groups from the folate cycle. Previously, we showed that the hypomorphic Mtrr^gt mutation in mice results in metabolic disruption, epigenetic instability, and a wide spectrum of developmental phenotypes (e.g. growth defects, congenital malformations) at midgestation that appear in subsequent wild-type generations. This transgenerational effect only occurs through the maternal lineage. Here, we explore whether the phenotypes that result from either intrinsic or ancestral Mtrr deficiency are sexually dimorphic. We found that no sexual dimorphism is apparent in either situation when the phenotypes were broadly or specifically defined. However, when we focused on the group of phenotypically normal conceptuses derived from maternal grandparental Mtrr deficiency, we observed an apparent increase in placental efficiency in each subsequent generation leading to F4 generation female embryos that weigh more than controls. These data suggest that ancestral abnormal folate metabolism may lead to male grandprogeny that are less able to adapt or female grandprogeny that are programmed to become more sensitive to folate availability in subsequent generations.

Congenital Diaphragmatic hernia - a review

Congenital Diaphragmatic hernia (CDH) is a condition characterized by a defect in the diaphragm leading to protrusion of abdominal contents into the thoracic cavity interfering with normal development of the lungs. The defect may range from a small aperture in the posterior muscle rim to complete absence of diaphragm.

The pathophysiology of CDH is a combination of lung hypoplasia and immaturity associated with persistent pulmonary hypertension of newborn (PPHN) and cardiac dysfunction. Prenatal assessment of lung to head ratio (LHR) and position of the liver by ultrasound are used to diagnose and predict outcomes. Delivery of infants with CDH is recommended close to term gestation. Immediate management at birth includes bowel decompression, avoidance of mask ventilation and endotracheal tube placement if required. The main focus of management includes gentle ventilation, hemodynamic monitoring and treatment of pulmonary hypertension followed by surgery. Although inhaled nitric oxide is not approved by FDA for the treatment of PPHN induced by CDH, it is commonly used.

Extracorporeal membrane oxygenation (ECMO) is typically considered after failure of conventional medical management for infants ≥ 34 weeks’ gestation or with weight >2 kg with CDH and no associated major lethal anomalies. Multiple factors such as prematurity, associated abnormalities, severity of PPHN, type of repair and need for ECMO can affect the survival of an infant with CDH. With advances in the management of CDH, the overall survival has improved and has been reported to be 70-90% in non-ECMO infants and up to 50% in infants who undergo ECMO.

Genetic analysis of rare coding mutations of CELSR1-3 in congenital heart and neural tube defects in Chinese people

The planar cell polarity (PCP) pathway is critical for proper embryonic development of the neural tube and heart. Mutations in these genes have previously been implicated in the pathogenesis of neural tube defects (NTDs), but not in congenital heart defects (CHDs) in humans. We systematically identified the mutation patterns of CELSR1-3, one family of the core PCP genes, in human cohorts composed of 352 individuals with NTDs, 412 with CHDs and matched controls. A total of 72 disease-specific, rare, novel, coding mutations were identified, of which 37 were identified in patients with CHDs and 36 in patients with NTDs. Most of these mutations differed between the two cohorts, because only one novel missense mutation in CELSR1 (c.2609G>A p.P870L) was identified in both NTD and CHD patients. Both in vivo and in vitro assays revealed that CELSR1 P870L is a gain-of-function mutation. It up-regulates not only the PCP pathway, but also canonical WNT signalling in cells, and also induces both NTDs and CHDs in zebrafish embryos. As almost equal numbers of mutations were identified in each cohort, our results provided the first evidence that mutations in CELSR genes are as likely to be associated with CHDs as with NTDs, although the specific mutations differ between the two cohorts. Such differences in mutation panels suggested that CELSRs [cadherin, EGF (epidermal growth factor), LAG (laminin A G-type repeat), seven-pass receptors)] might be regulated differently during the development of these two organ systems.

Epidemiology and Outcomes of Congenital Diaphragmatic Hernia in Croatia: A Population-Based Study

BACKGROUND

Outcomes of neonates with congenital diaphragmatic hernia (CDH) are variable; reports are frequently limited to the experience of single tertiary care centres-a possible source of bias. Population-based studies decrease survivor bias and provide additional insight into this high-mortality condition. The objective of this study was to examine the incidence and outcomes of CDH in Croatia.

METHODS

All cases of CDH in Croatia from 2001 through 2013 were ascertained from public health records. Overall and sex- and region-specific incidence rates were calculated, and characteristics associated with 1-year survival were assessed.

RESULTS

We identified 145 cases of CDH during the study period, for an incidence of 2.67 per 10 000 total births. The incidence did not differ by calendar year (P = 0.38) or geographic region (P = 0.67). There was a slightly higher incidence among males (rate ratio, 1.37, 95% CI 0.99, 1.91). The 1-year survival rate was 33.1% for the entire cohort and 47.9% for liveborns who received any treatment at an intensive care unit. From multivariable analysis, survival was decreased in neonates with left CDH, liver up (odds ratio 0.1, 95% CI, 0.03, 0.4) and increased when treated in a centre with higher case volume (odds ratio 12.8, 95% CI, 2.2, 72.1).

CONCLUSIONS

The incidence of CDH in Croatia is within the range of previous reports. Survival was substantially higher in neonates treated in a centre with higher case volume, which suggests that centralisation of medical care for CDH may be warranted in Croatia.

Neonatal outcomes in relation to sex differences: a national cohort survey in Taiwan

Background

An extensive assessment investigating the association between sex differences and neonatal outcomes is lacking. In the current study, we estimated the correlation of gender with adverse birth outcomes in a large cohort population.

Methods

National population-based data containing maternal and neonatal information in 2001 to 2010 were derived from the Health Promotion Administration, Taiwan. Singletons without high-risk pregnancy were further analyzed for the sex ratio of live births in relation to neonatal outcomes—including preterm birth, birth weight, neonatal death, delivery mode, and congenital anomaly. A multivariate logistic regression model was used to adjust for possible confounders.

Results

In total, 2,123,100 births were valid for the analysis. Overall, the sex ratio at birth (male/female) was 1.096. Compared to multiple births, the sex ratio was significantly higher with singleton births (p < 0.001). Among multiple births, the incidence of stillbirths was significantly higher in males than in females (p < 0.05). The sex ratio at gestational age (GA) <37 weeks was 1.332, and it declined proportionally with a rise in the GA to 0.899 at GA of ≥41 weeks. In contrast, the sex ratio was 0.850 at birth weight <3000 g, and it rose proportionally with a rise in the birth weight to 1.902 at birth weight ≥4000 g (macrosomia). Operative delivery was more common in males than in females (p < 0.001). The regression analysis showed greater risks of preterm birth, macrosomia, operative delivery, neonatal death, and congenital anomaly among male newborns.

Conclusions

Male gender carried higher risks of adverse neonatal outcomes, including preterm birth, macrosomia, operative delivery, neonatal death, and congenital anomaly. The data have clinical implications on health surveillance for plotting strategies in response to the unbalanced sex ratio in relation to the boy preference.

The Contribution of MRI after Fetal Anomalies Have Been Diagnosed by Ultrasound: Correlation with Postnatal Outcomes

Objective: The aim of this study was to investigate the additional value of fetal magnetic resonance imaging (MRI) in the assessment and management of fetuses with abnormal findings on ultrasound. Methods: A total of 257 patients who had fetal MRI following the ultrasound diagnosis of a fetal anomaly, or were at high risk, were included. The patients were grouped by referral category for fetal MRI. Fetal MRI was compared to ultrasound in the detection of anomalies, i.e. whether additional findings were identified and if this changed diagnosis, prognosis and management during pregnancy. Results: Ultrasound findings were confirmed on fetal MRI in 89% of the cases. Additional findings were seen with MRI in 28% of all patients. The diagnosis changed in 21% and the prognosis in 19% of the cases. Perinatal management changed in 8%. The antenatal findings were confirmed in all cases that had a postmortem examination following termination of pregnancy. In all the pregnancies that continued to delivery and for which the postnatal outcome is known, the findings correlated in 97% of the cases. Conclusion: Fetal MRI provided additional detection of fetal anomalies, leading to a change in diagnosis and prognosis in 19% of the cases. Neonatal and postmortem findings mostly confirmed the fetal MRI diagnosis, suggesting it to be a useful tool for clinical decision making in perinatal management.

Epidemiology of congenital diaphragmatic hernia in Europe: a register-based study

INTRODUCTION

Published prevalence rates of congenital diaphragmatic hernia (CDH) vary. This study aims to describe the epidemiology of CDH using data from high-quality, population-based registers belonging to the European Surveillance of Congenital Anomalies (EUROCAT).

METHODS

Cases of CDH delivered between 1980 and 2009 notified to 31 EUROCAT registers formed the population-based case series. Prevalence over time was estimated using multilevel Poisson regression, and heterogeneity between registers was evaluated from the random component of the intercept.

RESULTS

There were 3373 CDH cases reported among 12 155 491 registered births. Of 3131 singleton cases, 353 (10.4%) were associated with a chromosomal anomaly, genetic syndrome or microdeletion, 784 (28.2%) were associated with other major structural anomalies. The male to female ratio of CDH cases overall was 1:0.69. Total prevalence was 2.3 (95% CI 2.2 to 2.4) per 10 000 births and 1.6 (95% CI 1.6 to 1.7) for isolated CDH cases. There was a small but significant increase (relative risk (per year)=1.01, 95% credible interval 1.00-1.01; p=0.030) in the prevalence of total CDH over time but there was no significant increase for isolated cases (ie, CDH cases that did not occur with any other congenital anomaly). There was significant variation in total and isolated CDH prevalence between registers. The proportion of cases that survived to 1 week was 69.3% (1392 cases) for total CDH cases and 72.7% (1107) for isolated cases.

CONCLUSIONS

This large population-based study found an increase in total CDH prevalence over time. CDH prevalence also varied significantly according to geographical location. No significant association was found with maternal age.

Sex ratios among infants with birth defects, National Birth Defects Prevention Study, 1997-2009

A small number of population-based studies have examined sex differences among infants with birth defects. This study presents estimates of sex ratio for both isolated cases and those with multiple congenital anomalies, as well as by race/ethnicity. Male-female sex ratios and their 95% confidence intervals were calculated for 25,952 clinically reviewed case infants included in the National Birth Defects Prevention Study (1997-2009), a large population-based case-control study of birth defects. The highest elevations in sex ratios (i.e., male preponderance) among isolated non-cardiac defects were for craniosynostosis (2.12), cleft lip with cleft palate (2.01), and cleft lip without cleft palate (1.78); the lowest sex ratios (female preponderance) were for choanal atresia (0.45), cloacal exstrophy (0.46), and holoprosencephaly (0.64). Among isolated cardiac defects, the highest sex ratios were for aortic stenosis (2.88), coarctation of the aorta (2.51), and d-transposition of the great arteries (2.34); the lowest were multiple ventricular septal defects (0.52), truncus arteriosus (0.63), and heterotaxia with congenital heart defect (0.64). Differences were observed by race/ethnicity for some but not for most types of birth defects. The sex differences we observed for specific defects, between those with isolated versus multiple defects, as well as by race/ethnicity, demonstrate patterns that may suggest etiology and improve classification.

Major congenital anomalies in babies born with Down syndrome: a EUROCAT population-based registry study

Previous studies have shown that over 40% of babies with Down syndrome have a major cardiac anomaly and are more likely to have other major congenital anomalies. Since 2000, many countries in Europe have introduced national antenatal screening programs for Down syndrome. This study aimed to determine if the introduction of these screening programs and the subsequent termination of prenatally detected pregnancies were associated with any decline in the prevalence of additional anomalies in babies born with Down syndrome. The study sample consisted of 7,044 live births and fetal deaths with Down syndrome registered in 28 European population-based congenital anomaly registries covering seven million births during 2000-2010. Overall, 43.6% (95% CI: 42.4-44.7%) of births with Down syndrome had a cardiac anomaly and 15.0% (14.2-15.8%) had a non-cardiac anomaly. Female babies with Down syndrome were significantly more likely to have a cardiac anomaly compared to male babies (47.6% compared with 40.4%, P < 0.001) and significantly less likely to have a non-cardiac anomaly (12.9% compared with 16.7%, P < 0.001). The prevalence of cardiac and non-cardiac congenital anomalies in babies with Down syndrome has remained constant, suggesting that population screening for Down syndrome and subsequent terminations has not influenced the prevalence of specific congenital anomalies in these babies.

Perinatal outcome in relation to fetal sex in offspring to mothers with pre-gestational and gestational diabetes--a population-based study

AIM

The objective of the present study was to investigate if perinatal outcome differs with fetal sex in pregnancies with maternal Type 1 diabetes, Type 2 diabetes or gestational diabetes.

METHODS

This was a population-based cohort study, with data from the Medical Birth Registry in Sweden throughout the period 1998-2007. Singleton pregnancies with maternal Type 1 diabetes (n = 4092), Type 2 diabetes (n = 412) and gestational diabetes (n = 8602) were identified based on the International Classification of Diseases, 10th edition code. For comparison, 905 565 pregnancies without diabetes were included. The primary outcome was a composite outcome, consisting of any of the following diagnoses: perinatal mortality rate, major malformation, preterm delivery, acute respiratory disorders and neonatal hypoglycaemia. Logistic regression was used to obtain odds ratios for adverse outcomes in male offspring within the diabetic and reference cohorts, respectively.

RESULTS

In pregnancies with diabetes, maternal characteristics did not differ with fetal sex, except for a higher rate of Caesarean delivery in male offspring of women with Type 1 diabetes. Male infants to mothers with Type 1 diabetes and gestational diabetes had significantly increased odds of respiratory disorders [adjusted odds ratio (confidence interval) Type 1 diabetes: 1.50 (1.12-2.02); gestational diabetes: 1.81 (1.27-2.57)]. Male infants to mothers with gestational diabetes also had significantly increased odds of major malformations [adjusted odds ratio: 1.44 (1.07-1.93)]. In offspring of mothers with Type 2 diabetes, odds ratios of most outcomes were higher in male infants; however, not significantly different from female infants. In pregnancies without diabetes, male infants had significantly higher odds of all adverse outcomes, except perinatal mortality rate.

CONCLUSION

The risk of adverse perinatal outcome in offspring of mothers with Type 1 diabetes and gestational diabetes did not differ by sex, except for a higher risk in male infants for respiratory disorders. The risk of major malformations was also significantly increased in male offspring to mothers with gestational diabetes. In offspring of mothers with Type 2 diabetes, no significant differences between sexes were found.

Congenital malformations of pediatric surgical interest: prevalence, risk factors, and prenatal diagnosis between 2005 and 2012 in the capital city of a developing country. Bogotá, Colombia

BACKGROUND

Congenital anomalies (CAs) cause nearly one third of infant deaths worldwide. Various surveillance systems have been established, such as the Bogota Congenital Malformations Surveillance Program (BCMSP). Some CAs are of special interest to pediatric surgeons: omphalocele, gastroschisis, intestinal and esophageal atresia, anorectal malformations, vascular anomalies, diaphragmatic hernias, hypospadias and cryptorchidism. The aim of this study is to determine the prevalence of such CAs, and identify possible risk factors.

METHODS

Data from the BCMSP were collected between January 2005 and April 2012. CAs were classified in accordance with the ICD-10 and grouped for analysis purposes. Data on CA frequencies were obtained from the BCMSP. Association analyses were performed using the case-control methodology.

RESULTS

282,523 births were registered. 4682 (1.66%) had one or more CAs at birth. The prevalence of CAs requiring pediatric surgery was 1 in 1000. The most frequent CAs were vascular anomalies, hypospadias, and anorectal malformations. Exposure to external factors was significantly associated with selected CAs. 51% of selected birth defects were not diagnosed in prenatal ultrasound.

CONCLUSIONS

This study highlights the importance of evaluating the local prevalence of congenital malformations. We propose the creation of specialized centers in Bogota to manage patients with CAs.

Sex prevalence of major congenital anomalies in the United Kingdom: a national population-based study and international comparison meta-analysis

Background

The aim of this study was to assess sex differences in major congenital anomaly (CA) diagnoses within a national population sample; to examine the influence of sociodemographic and maternal factors on these risks; and to conduct a meta-analysis using estimates from other population-based studies.

Methods

We conducted a population-based study in a United Kingdom research database of prospectively collected primary care data (The Health Improvement Network) including children born 1990 to 2009 (n = 794,169) and identified major CA diagnoses using EUROCAT (European Surveillance of Congenital Anomalies) classification. Prevalence ratios (PR) were used to estimate the risk of CA in males compared with females for any CA, system-specific subgroups and specific CA diagnoses. In a subpopulation of children whose medical records were linked to their mothers', we assessed the effect of adjusting for sociodemographic and maternal factors on sex odds ratios. PRs were pooled with measures from previously published studies.

Results

The prevalence of any CA was 307/10,000 in males (95% CI, 302–313) and 243/10,000 in females (95% CI, 238–248). Overall the risk of any CA was 26% greater in males (PR (male: female) 1.26, 95% CI, 1.23–1.30) however there was considerable variation across specific diagnoses. The magnitude and direction of risk did not change for any specific CA upon adjustment for sociodemographic and maternal factors. Our PRs were highly consistent with those from previous studies.

Conclusion

The overall risk of CA is greater in males than females, although this masked substantial variation by specific diagnoses. Sociodemographic and maternal factors do not appear to affect these risks. Birth Defects Research (Part A) 100:79–91, 2014. © 2014 Wiley Periodicals, Inc.

Improved antenatal detection of congenital anomalies in women with pre-gestational diabetes: population-based cohort study

AIMS

To compare antenatal detection of congenital anomaly in women with and without pre-gestational diabetes and their pregnancy outcomes in a regional cohort study.

METHODS

Data from a total of 7148 singleton pregnancies with a congenital anomaly delivered between 1 January 1996 and 31 December 2008 were extracted from the Northern Diabetes in Pregnancy and Northern Congenital Abnormality Surveys. Antenatal ultrasound detection rates of congenital anomaly in pregnancies complicated by major non-chromosomal congenital anomaly and resulting in live birth, stillbirth, late miscarriage (20-23 weeks of gestation) or termination of pregnancy for a congenital anomaly, were compared between women with and without diabetes (120 and 7028, respectively).

RESULTS

A significantly higher rate of antenatal detection of congenital anomalies was observed in women with diabetes compared with women without diabetes (50.8 vs. 38.6%, respectively; relative risk 1.32; 95% CI 1.10-1.57; P = 0.003). Cardiovascular anomalies were the only group with a significantly higher antenatal detection rate in women with diabetes (31.8 vs. 10.4%; relative risk 3.05; 95% CI 1.95-4.76; P < 0.00001). This difference remained after excluding cases of ventricular septal defect (52.2 vs. 16.3%; relative risk 3.20; 95% CI 2.13-4.80; P < 0.0001). Among women with diabetes, male fetal sex was the only factor associated with a higher antenatal detection rate. There were no differences in the rates of termination of pregnancy, late miscarriage, stillbirth or infant death between groups.

CONCLUSIONS

Antenatal detection of cardiovascular anomalies was higher in women with diabetes, suggesting that recommendations for enhanced cardiovascular scanning may improve detection. Greater awareness of the increased risk of anomalies in other organ systems is needed.

Identification of novel candidate gene loci and increased sex chromosome aneuploidy among infants with conotruncal heart defects

Congenital heart defects (CHDs) are common malformations, affecting four to eight per 1,000 total births. Conotruncal defects are an important pathogenetic subset of CHDs, comprising nearly 20% of the total. Although both environmental and genetic factors are known to contribute to the occurrence of conotruncal defects, the causes remain unknown for most. To identify novel candidate genes/loci, we used array comparative genomic hybridization to detect chromosomal microdeletions/duplications. From a population base of 974,579 total births born during 1999-2004, we screened 389 California infants born with tetralogy of Fallot or d-transposition of the great arteries. We found that 1.7% (5/288) of males with a conotruncal defect had sex chromosome aneuploidy, a sevenfold increased frequency (relative risk = 7.0; 95% confidence interval 2.9-16.9). We identified eight chromosomal microdeletions/duplications for conotruncal defects. From these duplications and deletions, we found five high priority candidate genes (GATA4, CRKL, BMPR1A, SNAI2, and ZFHX4). This is the initial report that sex chromosome aneuploidy is associated with conotruncal defects among boys. These chromosomal microduplications/deletions provide evidence that GATA4, SNAI2, and CRKL are highly dosage sensitive genes involved in outflow tract development. Genome wide screening for copy number variation can be productive for identifying novel genes/loci contributing to non-syndromic common malformations.

Mutations in Lyar and p53 are synergistically lethal in female mice

BACKGROUND

Ly-1 antibody reactive clone (LYAR) is a nucleolar zinc finger protein that has been implicated in cell growth, self-renewal of embryonic stem cells, and medulloblastoma. To test whether LYAR is critical for cell growth and development, we generated Lyar mutant mice.

METHODS

Mice carrying the mutant Lyar(gt) allele were generated from embryonic stem cells that contained a gene-trap insertion in the Lyar gene. Phenotypic analyses were performed on Lyar mutant mice and mouse embryonic fibroblasts. Lyar(gt/gt) mice were crossed to mice lacking the p53 tumor suppressor protein and Lyar/p53 compound mutants scored for external abnormalities.

RESULTS

Lyar(gt/gt) homozygotes are viable, fertile, and indistinguishable from wild type littermates. However, the growth of Lyar(+/gt) and Lyar(gt/gt) mouse embryonic fibroblasts (MEFs) was impaired, coincident with an increase in the steady-state level of p53 and a key p53 effector of growth arrest, p21, suggesting that a cellular stress response is triggered in the absence of a wild type level of LYAR. Remarkably, the majority of Lyar(+/gt) and Lyar(gt/gt) female mice lacking p53 mice failed to survive. The neural tube defect (NTD) exencephaly was observed in ≈26% and ≈61% of female Lyar(+/gt;) p53(-/-) and Lyar(gt/gt;) p53(-/-) embryos, respectively.

CONCLUSIONS

Lyar/p53 mutant mice represent a new digenic model of NTDs. Furthermore, these studies identify Lyar as a novel candidate gene for a role in human NTDs. These results provide new data to support the idea that loss of a p53-mediated developmental checkpoint may increase the risk of NTDs owing to some germline mutations.

Hypothesis: the female excess in cranial neural tube defects reflects an epigenetic drag of the inactivating X chromosome on the molecular mechanisms of neural fold elevation

Females have long been known to be in excess among cranial neural tube defect (NTD) cases. Up to two thirds of human anencephalics and mouse exencephalics from various genetic causes are female, but the cause of this female excess is unknown. It appears not to be attributable to gonadal hormones, developmental delay in females, or preferential death of affected males. Recent studies of the Trp53 mouse mutant showed that exencephaly susceptibility depends on the presence of two X chromosomes, not the absence of the Y. Over a decade ago, we hypothesized that the relevant difference between female and male mammalian embryos at the time of cranial neural tube closure is the fact that females methylate most of the DNA in the large inactive X chromosome after every cell division, reducing the methylation available for other needs in female cells. Recently, the Whitelaw laboratory identified several proteins in mice (Momme D genes) involved in epigenetic silencing and methylation and shared in the silencing of transgenes, retrotransposons, and the inactive-X, and suggested that the inactive-X acts as a "sink" for epigenetic silencing proteins. The "inactive-X sink" hypothesis can be used to suggest expected changes in sex ratio in cranial NTDs in response to various genetic or environmental alterations. We recommend that observation of sex ratio become a standard component of all NTD studies. We suggest that the female excess among cranial NTDs is an epigenetic phenomenon whose molecular investigation will produce insight into the mechanisms underlying NTDs.

Peri-conception hyperglycaemia and nephropathy are associated with risk of congenital anomaly in women with pre-existing diabetes: a population-based cohort study

AIMS: The aim of this study was to quantify the risk of major congenital anomaly, and to assess the influence of peri-conception HbA(1c) and other clinical and socio-demographic factors on the risk of congenital anomaly occurrence in offspring of women with type 1 and type 2 diabetes diagnosed before pregnancy. METHODS: This was a population-based cohort study using linked data from registers of congenital anomaly and diabetes in pregnancy. A total of 401,149 singleton pregnancies (1,677 in women with diabetes) between 1996 and 2008 resulting in live birth, fetal death at ≥20 weeks' gestation or termination of pregnancy for fetal anomaly were included. RESULTS: The rate of non-chromosomal major congenital anomaly in women with diabetes was 71.6 per 1,000 pregnancies (95% CI 59.6, 84.9), a relative risk of 3.8 (95% CI 3.2, 4.5) compared with women without diabetes. There was a three- to sixfold increased risk across all common anomaly groups. In a multivariate analysis, peri-conception glycaemic control (adjusted OR [aOR] 1.3 [95% CI 1.2, 1.4] per 1% [11 mmol/mol] linear increase in HbA(1c) above 6.3% [45 mmol/mol]) and pre-existing nephropathy (aOR 2.5 [95% CI 1.1, 5.3]) were significant independent predictors of congenital anomaly. Associations with gestation at booking (aOR 1.1 [95% CI 1.0, 1.1]) and parity (aOR 1.6 [95% CI 1.0, 2. 5]) were not significant. Unadjusted risk was higher for women from deprived areas or who did not take folate. Type and duration of diabetes, ethnicity, age, BMI, preconception care, smoking and fetal sex were not associated with congenital anomaly risk. CONCLUSIONS: Peri-conception glycaemia is the most important modifiable risk factor for congenital anomaly in women with diabetes. The association with nephropathy merits further study.