Gastroschisis prevalence in Texas 1999-2003

Short and Medium-term Outcomes of Omphalocele and Gastroschisis: A Survey from a Tertiary Center

OBJECTIVE

 To characterize and compare the outcomes of omphalocele and gastroschisis from birth to 2 years of follow-up in a recent cohort at a tertiary center.

METHODS

 This is a retrospective clinical record review of all patients with gastroschisis and omphalocele admitted to the Neonatal Intensive Care Unit between January 2009 and December 2019.

RESULTS

 There were 38 patients, 13 of whom had omphalocele, and 25 of whom had gastroschisis. Associated anomalies were present in 6 patients (46.2%) with omphalocele and in 10 (41.7%) patients with gastroschisis. Compared with patients with omphalocele, those with gastroschisis had younger mothers (24.7 versus 29.6 years; p = 0.033), were born earlier (36 versus 37 weeks, p = 0.006), had lower birth weight (2365 ± 430.4 versus 2944.2 ± 571.9 g; p = 0.001), and had a longer hospital stay (24 versus 9 days, p = 0.001). The neonatal survival rate was 92.3% for omphalocele and 91.7% for gastroschisis. Thirty-four patients were followed-up over a median of 24 months; 13 patients with gastroschisis (59.1%) and 8 patients with omphalocele (66.7%) had at least one adverse event, mainly umbilical hernia (27.3% vs 41.7%), intestinal obstruction (31.8% vs 8.3%), or additional surgical interventions (27.3% vs 33.3%).

CONCLUSION

 Despite the high proportion of prematurity, low birth weight, and protracted recovery, gastroschisis and omphalocele (without chromosomal abnormalities) may achieve very high survival rates; on the other hand, complications may develop in the first years of life. Thus, a very positive perspective in terms of survival should be transmitted to future parents, but they should also be informed that substantial morbidity may occur in the medium term.

A spatial analysis of birth defects in Texas, 1999-2011

BACKGROUND

The etiologies of major birth defects are still unclear and few spatial analyses have been conducted in the United States. Spatial analyses of individual-level data can help elucidate environmental and social risk factors.

METHODS

We used generalized additive models to analyze 52,955 cases of neural tube defects, congenital heart defects (CHDs), gastroschisis, and orofacial cleft defects, and sampled from 642,399 controls born between 1999 and 2011 in Texas. The effect of geographic location was measured using a bivariable smooth term of geocoded birth address within a logistic regression framework. We calculated and mapped odds ratios (ORs) and 95% confidence intervals (CIs) for birth defects subtypes across Texas, and adjusted for maternal characteristics, environmental indicators, and community-level covariates. We also performed time-stratified spatiotemporal analyses for more prevalent birth defects.

RESULTS

Location was significantly associated with crude odds of all birth defects except hypoplastic left heart syndrome. After adjusting for maternal characteristics, environmental indicators, and community-level factors, ORs in many geographic areas were no longer statistically significant for most defects, especially CHDs. However, areas of significant and insignificant elevated risk remained for defects in all groups in North and South Texas, with ORs for ventricular septal defects increasing over time. Low risk of birth defects was often present in the northern part of East Texas.

CONCLUSION

Significant spatial patterns of birth defects were identified and varied depending on adjustment of different categories of covariates. Further investigation of areas with increased risks may aid in our understanding of birth defects.

Burden and consequence of birth defects in Nepal-evidence from prospective cohort study

Background

Every year an estimated 7.9 million babies are born with birth defect. Of these babies, more than 3 million die and 3.2 million have disability. Improving nationwide information on prevalence of birth defect, risk factor and consequence is required for better resource allocation for prevention, management and rehabilitation. In this study, we assess the prevalence of birth defect, associated risk factors and consequences in Nepal.

Method

This is a prospective cohort study conducted in 12 hospitals of Nepal for 18 months. All the women who delivered in the hospitals during the study period was enrolled. Independent researchers collected data on the social and demographic information using semi-structured questionnaire at the time of discharge and clinical events and birth outcome information from the clinical case note. Data were analyzed on the prevalence and type of birth defect. Logistic regression was done to assess the risk factor and consequences for birth defect.

Results

Among the total 87,242 livebirths, the prevalence of birth defects was found to be 5.8 per 1000 live births. The commonly occurring birth defects were anencephaly (3.95%), cleft lip (2.77%), cleft lip and palate (6.13%), clubfeet (3.95%), eye abnormalities (3.95%) and meningomyelocele (3.36%). The odds of birth defect was higher among mothers with age < 20 years (adjusted Odds ratio (aOR) 1.64; 95% CI, 1.18–2.28) and disadvantaged ethnicity (aOR 1.78; 95% CI, 1.46–2.18). The odds of birth asphyxia was twice fold higher among babies with birth defect (aOR 1.88; 95% CI, 1.41–2.51) in reference with babies without birth defect. The odds of neonatal infection was twice fold higher among babies with birth defect (aOR 1.82; 95% CI, 1.12–2.96) in reference with babies without birth defect. Babies with birth defect had three-fold risk of pre-discharge mortality (aOR 3.00; 95% CI, 1.93–4.69).

Conclusion

Maternal age younger than 20 years and advantaged ethnicity were risk factors of birth defects. Babies with birth defect have high risk for birth asphyxia, neonatal infection and pre-discharge mortality at birth. Further evaluation on the care provided to babies who have birth defect is warranted.

Funding

Swedish Research Council (VR).

Trends in prevalence and spatiotemporal distribution of gastroschisis in Arkansas, 1998-2015

BACKGROUND

Arkansas (AR) had the highest prevalence of gastroschisis in a recent study including 15 U.S. states. Our objective was to evaluate trends in prevalence and the spatiotemporal distribution of gastroschisis in AR.

METHODS

Infants with gastroschisis, born 1998-2015, were identified from the Arkansas Reproductive Health Monitoring System. Birth record data were used as denominators for calculations. Maternal residence at delivery was geocoded for spatial analyses. Annual prevalence rates (PRs) were calculated. Joinpoint regression analysis was performed to examine trends in gastroschisis and report the annual percent changes (APCs) in PRs. Spatiotemporal analyses identified counties with unusually high PRs of gastroschisis. Poisson regression, including county, year, and county*year indicators, was fit to evaluate the PRs of gastroschisis, while adjusting for county-level maternal variables.

RESULTS

We identified 401 cases of gastroschisis among 694,459 live births. The overall PR of gastroschisis was 5.8/10,000 live births. The prevalence of gastroschisis had a significant APC of +5.3% (p < .0001) between 1998 and 2012, followed by a nonsignificant yearly average decrease of -17% through 2015 (p = 0.2). The Emerging Hot Spot Analysis and SaTScan identified an overlapping five-county cluster from 2006 to 2013. Poisson regression model, including county (inside vs. outside cluster), time (before vs. after 2006), and county*time indicators, was fit to evaluate the PRs of gastroschisis. The model did not confirm the presence of a spatiotemporal cluster, once it adjusted for county-level maternal characteristics (p = .549).

CONCLUSION

Close monitoring of rates of gastroschisis is warranted to determine if the PRs of gastroschisis continue to decline in AR.

Major birth defects in the Brazilian side of the triple border: a population-based cross-sectional study

Background

Major birth defects increase the risk of fetal death and pediatric hospitalization, which also impact on healthcare costs. Sociodemographic factors can drastically affect reproductive health and be used to discriminate the exposure to hidden risk factors. Foz do Iguassu is a Brazilian city located in the triple-border region of Brazil / Paraguay / Argentina with high rates of birth defects. However no study aimed to verify factors associated with this incidence or preventive care is reported. The current work investigated the prevalence of major birth defects and its association with maternal sociodemographic factors in Foz do Iguassu.

Methods

In this population-based cross-sectional study we used data of all live births occurred in Foz do Iguassu from 2012 to 2017. The associated sociodemographic variables such as maternal age, maternal education, maternal race, country of residence, maternal parity and onset of prenatal care were analyzed. Each major birth defect was described according to absolute and relative frequencies, Kruskal-Wallis and logistic regression models were used to evaluate variables associated with selected birth defects.

Results

The most prevalent major birth defects were Cleft Lip and/or Palate (9.5/10,000), gastroschisis (6.93/10,000), spina bifida (5.53/10,000), hydrocephalus (5.53/10,000), hypospadias (4.55/10,000), Down syndrome (4.23/10,000), anencephaly (2.93/10,000), anorectal atresia / stenosis (1.95/10,000), undetermined sex (1.95/10,000), esophageal atresia / stenosis with or without fistula (1.63/10,000) and limb reduction defects (1.30/10,000). Maternal age was associated with gastroschisis and Down syndrome. Only maternal education up to 7 years was statistically associated with major birth defects considering all other sociodemographic variables.

Conclusion

Cleft Lip and/or Palate and Gastroschisis prevalence were higher than those found in the literature. This findings may suggest a distinct epidemiological behavior regarding major birth defects in the region. The work opens new perspectives for birth defects risk factors in the triple-border.

Population-based birth defects data in the United States, 2012-2016: A focus on abdominal wall defects

BACKGROUND/OBJECTIVES

In this report, the National Birth Defects Prevention Network (NBDPN) examines and compares gastroschisis and omphalocele for a recent 5-year birth cohort using data from 30 population-based birth defect surveillance programs in the United States.

METHODS

As a special call for data for the 2019 NBDPN Annual Report, state programs reported expanded data on gastroschisis and omphalocele for birth years 2012-2016. We estimated the overall prevalence (per 10,000 live births) and 95% confidence intervals (CI) for each defect as well as by maternal race/ethnicity, maternal age, infant sex, and case ascertainment methodology utilized by the program (active vs. passive). We also compared distribution of cases by maternal and infant factors and presence/absence of other birth defects.

RESULTS

The overall prevalence estimates (per 10,000 live births) were 4.3 (95% CI: 4.1-4.4) for gastroschisis and 2.1 (95% CI: 2.0-2.2) for omphalocele. Gastroschisis was more frequent among young mothers (<25 years) and omphalocele more common among older mothers (>40 years). Mothers of infants with gastroschisis were more likely to be underweight/normal weight prior to pregnancy and mothers of infants with omphalocele more likely to be overweight/obese. Omphalocele was twice as likely as gastroschisis to co-occur with other birth defects.

CONCLUSIONS

This report highlights important differences between gastroschisis and omphalocele. These differences indicate the importance of distinguishing between these defects in epidemiologic assessments. The report also provides additional data on co-occurrence of gastroschisis and omphalocele with other birth defects. This information can provide a basis for future research to better understand these defects.

Bioinformatic Analysis of Gene Variants from Gastroschisis Recurrence Identifies Multiple Novel Pathogenetic Pathways: Implication for the Closure of the Ventral Body Wall

We investigated whether likely pathogenic variants co-segregating with gastroschisis through a family-based approach using bioinformatic analyses were implicated in body wall closure. Gene Ontology (GO)/Panther functional enrichment and protein-protein interaction analysis by String identified several biological networks of highly connected genes in UGT1A3, UGT1A4, UGT1A5, UGT1A6, UGT1A7, UGT1A8, UGT1A9, UGT1A10, AOX1, NOTCH1, HIST1H2BB, RPS3, THBS1, ADCY9, and FGFR4. SVS–PhoRank identified a dominant model in OR10G4 (also as heterozygous de novo), ITIH3, PLEKHG4B, SLC9A3, ITGA2, AOX1, and ALPP, including a recessive model in UGT1A7, UGT1A6, PER2, PTPRD, and UGT1A3. A heterozygous compound model was observed in CDYL, KDM5A, RASGRP1, MYBPC2, PDE4DIP, F5, OBSCN, and UGT1A. These genes were implicated in pathogenetic pathways involving the following GO related categories: xenobiotic, regulation of metabolic process, regulation of cell adhesion, regulation of gene expression, inflammatory response, regulation of vascular development, keratinization, left-right symmetry, epigenetic, ubiquitination, and regulation of protein synthesis. Multiple background modifiers interacting with disease-relevant pathways may regulate gastroschisis susceptibility. Based in our findings and considering the plausibility of the biological pattern of mechanisms and gene network modeling, we suggest that the gastroschisis developmental process may be the consequence of several well-orchestrated biological and molecular mechanisms which could be interacting with gastroschisis predispositions within the first ten weeks of development.

Developing and implementing an interventional bundle to reduce mortality from gastroschisis in low-resource settings

Background: Gastroschisis is associated with less than 4% mortality in high-income countries and over 90% mortality in many tertiary paediatric surgery centres across sub-Saharan Africa (SSA). The aim of this trial is to develop, implement and prospectively evaluate an interventional bundle to reduce mortality from gastroschisis in seven tertiary paediatric surgery centres across SSA. Methods: A hybrid type-2 effectiveness-implementation, pre-post study design will be utilised. Using current literature an evidence-based, low-technology interventional bundle has been developed. A systematic review, qualitative study and Delphi process will provide further evidence to optimise the interventional bundle and implementation strategy. The interventional bundle has core components, which will remain consistent across all sites, and adaptable components, which will be determined through in-country co-development meetings. Pre- and post-intervention data will be collected on clinical, service delivery and implementation outcomes for 2-years at each site. The primary clinical outcome will be all-cause, in-hospital mortality. Secondary outcomes include the occurrence of a major complication, length of hospital stay and time to full enteral feeds. Service delivery outcomes include time to hospital and primary intervention, and adherence to the pre-hospital and in-hospital protocols.  Implementation outcomes are acceptability, adoption, appropriateness, feasibility, fidelity, coverage, cost and sustainability. Pre- and post-intervention clinical outcomes will be compared using Chi-squared analysis, unpaired t-test and/or Mann-Whitney U test. Time-series analysis will be undertaken using Statistical Process Control to identify significant trends and shifts in outcome overtime. Multivariate logistic regression analysis will be used to identify clinical and implementation factors affecting outcome with adjustment for confounders. Outcome: This will be the first multi-centre interventional study to our knowledge aimed at reducing mortality from gastroschisis in low-resource settings. If successful, detailed evaluation of both the clinical and implementation components of the study will allow sustainability in the study sites and further scale-up. Registration: ClinicalTrials.gov Identifier NCT03724214.

Improving outcomes for neonates with gastroschisis in low-income and middle-income countries: a systematic review protocol

INTRODUCTION

There is a significant disparity in outcomes for neonates with gastroschisis in high-income countries (HICs) compared with low-income and middle-income countries (LMICs). Many LMICs report mortality rates between 75% and 100% compared with <4% in HICs.

AIM

To undertake a systematic review identifying postnatal interventions associated with improved outcomes for gastroschisis in LMICs.

METHODS AND ANALYSIS

Three search strings will be combined: (1) neonates; (2) gastroschisis and other gastrointestinal congenital anomalies requiring similar surgical care; (3) LMICs. Databases to be searched include MEDLINE, EMBASE, Scopus, Web of Science, ProQuest Dissertations and Thesis Global, and the Cochrane Library. Grey literature will be identified through Open-Grey, ClinicalTrials.gov, WHO International Clinical Trials Registry and ISRCTN registry (Springer Nature). Additional studies will be sought from reference lists of included studies. Study screening, selection, data extraction and assessment of methodological quality will be undertaken by two reviewers independently and team consensus sought on discrepancies. The primary outcome of interest is mortality. Secondary outcomes include complications, requirement for ventilation, parenteral nutrition duration and length of hospital stay. Tertiary outcomes include service delivery and implementation outcomes. The methodology of the studies will be appraised. Descriptive statistics and outcomes will be summarised and discussed.

ETHICS AND DISSEMINATION

Ethical approval is not required since no new data are being collected. Dissemination will be via open access publication in a peer-reviewed medical journal and distribution among global health, global surgery and children's surgical collaborations and international conferences.

CONCLUSION

This study will systematically review literature focused on postnatal interventions to improve outcomes from gastroschisis in LMICs. Findings can be used to help inform quality improvement projects in low-resource settings for patients with gastroschisis. In the first instance, results will be used to inform a Wellcome Trust-funded multicentre clinical interventional study aimed at improving outcomes for gastroschisis across sub-Saharan Africa.

PROSPERO REGISTRATION NUMBER

CRD42018095349.

Care of infants with gastroschisis in low-resource settings

There is great global disparity in the outcome of infants born with gastroschisis. Mortality approaches 100% in many low income countries. Barriers to better outcomes include lack of antenatal diagnosis, deficient pre-hospital care, ineffective neonatal resuscitation and venous access, limited intensive care facilities, poor access to the operating theatre and safe neonatal anesthesia, and lack of neonatal parenteral nutrition. However, lessons can be learned from the evolution in management of gastroschisis in high-income countries, generic efforts to improve neonatal survival in low- and middle-income countries as well as specific gastroschisis management initiatives in low-resource settings. Micro and meso-level interventions include educational outreach programs, and pre and in hospital management protocols that focus on resuscitation and include the delay or avoidance of early neonatal anesthesia by using a preformed silo or equivalent. Furthermore, multidisciplinary team training, nurse empowerment, and the intentional involvement of mothers in monitoring and care provision may contribute to improving survival. Macro level interventions include the incorporation of ultrasound into World Health Organisation antenatal care guidelines to improve antenatal detection and the establishment of the infrastructure to enable parenteral nutrition provision for neonates in low- and middle-income countries. On a global level, gastroschisis has been suggested as a bellwether condition for evaluating access to and outcomes of neonatal surgical care provision.

Trends in incidence and outcomes of gastroschisis in the United States: analysis of the national inpatient sample 2010-2014

PURPOSE

Gastroschisis is a severe congenital anomaly associated with a significant morbidity and mortality. There are limited temporal trend data on incidence, mortality, length of stay, and hospital cost of gastroschisis. Our aim was to study these temporal trends using the National Inpatient Sample (NIS).

METHODS

We identified all neonatal admissions with a diagnosis of gastroschisis within the NIS from 2010 through 2014. We limited admission age to ≤ 28 days and excluded all those transferred to other hospitals. We estimated gastroschisis incidence, mortality, length of hospital stay, and cost of hospitalization. For continuous variables, trends were analyzed using survey regression. Cochrane-Armitage trend test was used to analyze trends for categorical variables. P < 0.05 was considered as significant.

RESULTS

The incidence of gastroschisis increased from 4.5 to 4.9/10,000 live births from 2010 through 2014 (P = 0.01). Overall mortality was 3.5%, median length of stay was 35 days (95% CI 26-55 days), and median cost of hospitalization was $75,859 (95% CI $50,231-$122,000). After adjusting for covariates, there was no statistically significant change in mortality (OR = 1.13; 95% CI 0.87-1.48), LOS (β = - 2.1 ± 3.5; 95% CI - 9.0 to 4.8) and hospital cost (β = - 2.137 ± 10.813; 95% CI - 23,331 to 19,056) with each calendar year increase on multivariate logistic regression analysis.

CONCLUSION

The incidence of neonates with gastroschisis increased between 2010 and 2014. Incidence was highest in the West. No difference in mortality and resource utilization was observed.

Evaluation of Early Onset Sepsis, Complete Blood Count, and Antibiotic Use in Gastroschisis

OBJECTIVE

Gastroschisis is a congenital defect in which the abdominal viscera herniate through the abdominal wall. In this population, antibiotics are often initiated immediately following delivery; however, this may be unnecessary as infections typically develop as a consequence of chronic issues in gastroschisis. The objective of this study was to evaluate the incidence of culture positive early onset sepsis, the reliability of the immature to mature neutrophil count (I:T) ratio as an infectious biomarker, and antibiotic use in infants with gastroschisis.

STUDY DESIGN

This retrospective chart review analyzed clinical data from 103 infants with gastroschisis and 103 weight-matched controls that were evaluated for early onset infection.

RESULTS

Compared with the control group, there was a significantly increased percentage of infants with an I:T ratio > 0.2 in the gastroschisis group (43% vs. 12%, p < 0.001) and an increased percentage of infants exposed to greater than 5 days of antibiotics regardless of their I:T ratio (75% vs. 6%, p < 0.001). There were no episodes of culture positive early onset sepsis in either group.

CONCLUSION

Our results indicate that I:T ratio is not a reliable marker of infection in gastroschisis, and suggest that empiric septic evaluation and antibiotic use, immediately following delivery in gastroschisis infants, may be unnecessary.

Decreasing prevalence and time trend of gastroschisis in 14 cities of Liaoning Province: 2006-2015

To identify trends in the prevalence of gastroschisis on the basis of a large population-based observation study with cases identified by the Liaoning Birth Defects Registry including 14 cities over the course of a 10-year period. Data were obtained from the aforementioned registry which was maintained by the Liaoning Women and Children's Health Hospital, a comprehensive care institution as well as being responsible for the women's and children's health care guidance in this province. Gastroschisis prevalence, percent change, annual percent change (APC), and contribution rates of each city were calculated. We observed 747 cases of gastroschisis among 3,248,954 live births, for a prevalence of 2.30 per 10,000 births. The gastroschisis prevalence significantly decreased by 12.63% per year in Liaoning Province. Although the decreasing trends were observed in all these 14 cities, significant results were only observed in Shenyang (APC = -16.31%), Tieling (APC = -20.23%), and Chaoyang (APC = -13.50%). Notably, Tieling, Shenyang, and Yingkou were the three major cities which contributed almost 37.17% of the decreasing trend of gastroschisis in Liaoning Province. In conclusion, our findings demonstrate that the prevalence of gastroschisis has been decreasing during the recent decade among 14 cities in Liaoning Province.

Spatial analysis of gastroschisis in Massachusetts and Texas

PURPOSE

Previous research has suggested gastroschisis, a congenital malformation, may be linked to environmental or infectious factors and cases can occur in clusters. The objective of this study was to identify geographic areas of elevated gastroschisis risk.

METHODS

Cases of gastroschisis were identified from birth defect registries in Massachusetts and Texas. Random samples of live births were selected as controls. Generalized additive models were used to create a continuous map surface of odds ratios (ORs) by smoothing over latitude and longitude. Maternal age, race/ethnicity, education, cigarette smoking, and insurance status (MA only) were assessed for confounding. We used permutation tests to identify statistically significant areas of increased risk.

RESULTS

An area of increased risk was identified in North Central Massachusetts but was not significant after adjustment (P value = .07; OR = 2.0). In Texas, two statistically significant areas of increased risk were identified after adjustment (P value = .02; OR = 1.3 and 1.2). Texas had sufficient data to assess the combination of space and time, which identified an increased risk in 2003 and 2004.

CONCLUSIONS

This study suggests there were areas of elevated gastroschisis risk in Massachusetts and Texas, which cannot be explained by the risk factors we assessed. Additional exploration of underlying artifactual, environmental, infectious, or behavioral factors may further our understanding of gastroschisis.

Maternal parity and the risk of congenital heart defects in offspring: a dose-response meta-analysis of epidemiological observational studies

Background

Epidemiological studies have reported conflicting results regarding maternal parity and the risk of congenital heart defects (CHDs). However, a meta-analysis of the association between maternal parity and CHDs in offspring has not been conducted.

Methods

We searched MEDLINE and EMBASE for articles catalogued between their inception and March 8, 2014; we identified relevant published studies that assessed the association between maternal parity and CHD risk. Two authors independently assessed the eligibility of the retrieved articles and extracted data from them. Study-specific relative risk estimates were pooled by random-effects or fixed-effects models. From the 11272 references, a total of 16 case-control studies and 3 cohort studies were enrolled in this meta-analysis.

Results

The overall relative risk of CHD in parous versus nulliparous women was 1.01 (95% CI, 0.97–1.06; Q = 32.34; P = 0.006; I² = 53.6%). Furthermore, we observed a significant association between the highest versus lowest parity number, with an overall RR = 1.20 (95% CI, 1.10–1.31; (Q = 74.61, P<0.001, I² = 82.6%). A dose–response analysis also indicated a positive effect of maternal parity on CHD risk, and the overall increase in relative risk per one live birth was 1.06 (95% CI, 1.02–1.09); Q = 68.09; P<0.001; I² = 80.9%). We conducted stratified and meta-regression analyses to identify the origin of the heterogeneity among studies. A Galbraith plot was created to graphically assess the sources of heterogeneity.

Conclusion

In summary, this meta-analysis provided a robust estimate of the positive association between maternal parity and risk of CHD.

Maternal residential atrazine exposure and gastroschisis by maternal age

Previous literature has suggested a link between maternal exposure to atrazine (the most commonly used herbicide in the US) and risk for gastroschisis (a birth defect that involves incomplete closure of the abdominal wall). Our objective was to evaluate the relationship between maternal atrazine exposure and gastroschisis risk by maternal age. We analyzed data for 1,161 cases with isolated gastroschisis and 8,390 controls delivered in Texas from 1999 through 2008. We estimated atrazine exposure based on maternal county of residence and data from the United States Geological Survey. Logistic regression was conducted among all subjects, and separately among offspring of women <25 and ≥25 years. Risk for gastroschisis in offspring was significantly increased for women ≥25 years with high levels of residential atrazine exposure compared to low (adjusted odds ratio: 1.97, 95 % confidence interval 1.19-3.26). This association was not observed among women <25 years. Our results provide additional insight into the suspected relationship of gastroschisis with atrazine. This relationship appears to be different in older versus younger mothers, providing further evidence that the etiology of gastroschisis may vary based on maternal age.

The association between race/ethnicity and major birth defects in the United States, 1999-2007

OBJECTIVES

We investigated the relationship between race/ethnicity and 27 major birth defects.

METHODS

We pooled data from 12 population-based birth defects surveillance systems in the United States that included 13.5 million live births (1 of 3 of US births) from 1999 to 2007. Using Poisson regression, we calculated prevalence estimates for each birth defect and 13 racial/ethnic groupings, along with crude and adjusted prevalence ratios (aPRs). Non-Hispanic Whites served as the referent group.

RESULTS

American Indians/Alaska Natives had a significantly higher and 50% or greater prevalence for 7 conditions (aPR = 3.97; 95% confidence interval [CI] = 2.89, 5.44 for anotia or microtia); aPRs of 1.5 to 2.1 for cleft lip, trisomy 18, and encephalocele, and lower, upper, and any limb deficiency). Cubans and Asians, especially Chinese and Asian Indians, had either significantly lower or similar prevalences of these defects compared with non-Hispanic Whites, with the exception of anotia or microtia among Chinese (aPR = 2.08; 95% CI = 1.30, 3.33) and Filipinos (aPR = 1.90; 95% CI = 1.10, 3.30) and tetralogy of Fallot among Vietnamese (aPR = 1.60; 95% CI = 1.11, 2.32).

CONCLUSIONS

This is the largest population-based study to our knowledge to systematically examine the prevalence of a range of major birth defects across many racial/ethnic groups, including Asian and Hispanic subgroups. The relatively high prevalence of birth defects in American Indians/Alaska Natives warrants further attention.

Association between maternal age and birth defects of unknown etiology: United States, 1997-2007

BACKGROUND

Birth defects affect 3% of babies born, and are one of the leading causes of infant mortality. Both younger and older maternal age may pose increased risks for certain birth defects. This study assessed the relationship between maternal age at the estimated delivery date and the risk for birth defects.

METHODS

Data were obtained from the National Birth Defects Prevention Study, a population-based case-control study including mothers across 10 states. Maternal age was stratified into six categories: <20, 20 to 24, 25 to 29, 30 to 34, 35 to 39, and ≥40 years, and also analyzed as a continuous variable. Logistic regression models adjusted formaternal race/ethnicity, education, body mass index (BMI), folic acid use, smoking, gravidity, and parental age difference were used to estimate adjusted odds ratios (aORs) and 95% confidence intervals (CIs).

RESULTS

For maternal age <20 years, associations with total anomalous pulmonary venous return (aOR, 2.3; 95% CI, 1.3-4.0), amniotic band sequence (aOR, 2.4; 95% CI, 1.5-3.8), and gastroschisis (aOR, 6.1; 95% CI, 4.8-8.0) were observed. For the ≥40 year age group, associations with several cardiac defects, esophageal atresia (aOR, 2.9; 95% CI, 1.7-4.9), hypospadias (aOR, 2.0; 95% CI, 1.4-3.0), and craniosynostosis (aOR, 1.6; 95% CI, 1.1-2.4) were observed. Results using maternal age as a continuous variable were consistent with those that used categorized maternal age.

CONCLUSION

Elucidating risk factors specific to women ateither extreme of maternal age may offer prevention opportunities. All women should be made aware of prevention opportunities, such as folic acid supplementation, to reduce the occurrence of birth defects.

Is maternal parity an independent risk factor for birth defects?

BACKGROUND

Although associations between maternal parity and birth defects have been observed previously, few studies have focused on the possibility that parity is an independent risk factor for birth defects. We investigated the relation between levels of parity and a range of birth defects, adjusting each defect group for the same covariates.

METHODS

We included infants who had an estimated delivery date between 1997 and 2007 and participated in the National Birth Defects Prevention Study, a multisite case-control study. Cases included infants or fetuses belonging to 38 phenotypes of birth defects (n = 17,908), and controls included infants who were unaffected by a major birth defect (n = 7173). Odds ratios (ORs) were adjusted for 12 covariates using logistic regression.

RESULTS

Compared with primiparous mothers, nulliparous mothers were more likely to have infants with amniotic band sequence, hydrocephaly, esophageal atresia, hypospadias, limb reduction deficiencies, diaphragmatic hernia, omphalocele, gastroschisis, tetralogy of Fallot, and septal cardiac defects, with significant ORs (1.2 to 2.3). Compared with primiparous mothers, multiparous mothers had a significantly increased risk of omphalocele, with an OR of 1.5, but had significantly decreased risk of hypospadias and limb reduction deficiencies, with ORs of 0.77 and 0.77.

CONCLUSIONS

Nulliparity was associated with an increased risk of specific phenotypes of birth defects. Most of the phenotypes associated with nulliparity in this study were consistent with those identified by previous studies. Research into biologic or environmental factors that are associated with nulliparity may be helpful in explaining some or all of these associations.