National Birth Defects Prevention Network Research Articles

Birth defects surveillance: Working together to advance science

AbstractSince 2000, the National Birth Defects Prevention Network (NBDPN), in collaboration with the US National Center on Birth Defects and Developmental Disabilities at the Centers for Disease Control and Prevention, has provided a special issue of Birth Defects Research focused on advancing the field of birth defects surveillance, epidemiology, and public health practice. The annual NBDPN special issue consists of contributed manuscripts using birth defects surveillance data for epidemiologic research or for improving birth defects surveillance methods. This year, our special issue includes updated national prevalence estimates for selected major birth defects, seven original research papers, and an invited editorial. Several of the accepted manuscripts highlight collaborative efforts between birth defects surveillance systems across the country: through the NBDPN, the National Birth Defects Prevention Study, and the Muscular Dystrophy Surveillance, Tracking, and Research Network. These studies offer examples of the power of pooling data and leveraging resources to conduct high‐quality birth defects research.

Risk of birth defects in pregnant persons with sleep-disordered breathing during pregnancy.

As many as one in four pregnant women may experience sleep-disordered breathing (SDB) during pregnancy. The same sequelae of SDB, such as insulin resistance and inflammation, have been implicated in the development of certain birth defects. This is a secondary analysis of the SDB substudy of the Nulliparous Pregnancy Outcomes Study: Monitoring Mothers-to-Be study, which included 2106 participants who had a sufficiency sleep study at two visits at different time points in pregnancy. SDB was based on a self-administered home sleep apnea test with data scored by trained, blinded research polysomnologists. SDB was defined as an apnea-hypopnea index (AHI) ≥5. The primary outcome of this analysis was any of the 45 non-chromosomal birth defects included in the National Birth Defects Prevention Network Annual Report. In this cohort, the overall rate of birth defects was 3.1%. The prevalence was similar between those without SDB (3.0%) and those with only mid-pregnancy SDB (3.4%), but was higher in those with early-pregnancy SDB (6.7%). After adjusting for maternal age, chronic hypertension, pregestational diabetes, and body mass index (BMI), there were no statistically significant differences in the risk of birth defects by subject SDB status. Further studies to evaluate the effect of prepregnancy and early-pregnancy SDB on the fetus, as well as the risk of specific birth defects and neonatal outcomes in those with an objectively measured diagnosis of SDB, are still needed.

Scientific impact of the National Birth Defects Prevention Network multistate collaborative publications.

Given the lack of a national, population-based birth defects surveillance program in the United States, the National Birth Defects Prevention Network (NBDPN) has facilitated important studies on surveillance, research, and prevention of major birth defects. We sought to summarize NBDPN peer-reviewed publications and their impact. We obtained and reviewed a curated list of 49 NBDPN multistate collaborative publications during 2000-2022, as of December 31, 2022. Each publication was reviewed and classified by type (e.g., risk factor association analysis). Key characteristics of study populations and analytic approaches used, along with publication impact (e.g., number of citations), were tabulated. NBDPN publications focused on prevalence estimates (N = 17), surveillance methods (N = 11), risk factor associations (N = 10), mortality and other outcomes among affected individuals (N = 6), and descriptive epidemiology of various birth defects (N = 5). The most cited publications were those that reported on prevalence estimates for a spectrum of defects and those that assessed changes in neural tube defects (NTD) prevalence following mandatory folic acid fortification in the United States. Results from multistate NBDPN publications have provided critical information not available through other sources, including US prevalence estimates of major birth defects, folic acid fortification and NTD prevention, and improved understanding of defect trends and surveillance efforts. Until a national birth defects surveillance program is established in the United States, NBDPN collaborative publications remain an important resource for investigating birth defects and informing decisions related to health services planning of secondary disabilities prevention and care.

Changes in Spina Bifida Lesion Level After Folic Acid Fortification in the US

Changes in Spina Bifida Lesion Level After Folic Acid Fortification in the US

Prevalence and descriptive epidemiology of Turner syndrome in the United States, 2000-2017: A report from the National Birth Defects Prevention Network.

The lack of United States population-based data on Turner syndrome limits assessments of prevalence and associated characteristics for this sex chromosome abnormality. Therefore, we collated 2000-2017 data from seven birth defects surveillance programs within the National Birth Defects Prevention Network. We estimated the prevalence of karyotype-confirmed Turner syndrome diagnosed within the first year of life. We also calculated the proportion of cases with commonly ascertained birth defects, assessed associations with maternal and infant characteristics using prevalence ratios (PR) with 95% confidence intervals (CI), and estimated survival probability. The prevalence of Turner syndrome of any pregnancy outcome was 3.2 per 10,000 female live births (95% CI=3.0-3.3, program range: 1.0-10.4), and 1.9 for live birth and stillbirth (≥20 weeks gestation) cases (95% CI=1.8-2.1, program range: 0.2-3.9). Prevalence was lowest among cases born to non-Hispanic Black women compared to non-Hispanic White women (PR=0.5, 95% CI=0.4-0.6). Coarctation of the aorta was the most common defect (11.6% of cases), and across the cohort, individuals without hypoplastic left heart had a five-year survival probability of 94.6%. The findings from this population-based study may inform surveillance practices, prenatal counseling, and diagnosis. We also identified racial and ethnic disparities in prevalence, an observation that warrants further investigation.

Prevalence and Clustering of Congenital Heart Defects Among Boys With Hypospadias

Hypospadias is a common birth defect of the male urinary tract that may be isolated or may co-occur with other structural malformations, including congenital heart defects (CHDs). The risk for co-occurring CHDs among boys with hypospadias remains unknown, which limits screening and genetic testing strategies. To characterize the risk of major CHDs among boys born with hypospadias. This retrospective cohort study used data from population-based birth defect surveillance programs on all male infants born in 11 US states from January 1, 1995, to December 31, 2014. Statistical analysis was performed from September 2, 2020, to March 25, 2022. Hypospadias. Demographic and diagnostic data were obtained from 2 active state-based birth defect surveillance programs for primary analyses, the Texas Birth Defects Registry and the Arkansas Reproductive Health Monitoring System, with validation among 9 additional states in the National Birth Defects Prevention Network (NBDPN). Birth defect diagnoses were identified using the British Pediatric Association coding for hypospadias (exposure) and major CHDs (primary outcomes). Maternal covariates and birth year were also abstracted from the vital records. Poisson regression was used to estimate adjusted prevalence ratios and 95% CIs for major CHDs within Texas and Arkansas and combined using inverse variance-weighted meta-analysis. Findings were validated using the NBDPN. Among 3.7 million pregnancies in Texas and Arkansas, 1485 boys had hypospadias and a co-occurring CHD. Boys with hypospadias were 5.8 times (95% CI, 5.5-6.1) more likely to have a co-occurring CHD compared with boys without hypospadias. Associations were observed for every specific CHD analyzed among boys with hypospadias, occurred outside of chromosomal anomalies, and were validated in the NBDPN. An estimated 7.024% (95% CI, 7.020%-7.028%) of boys with hypospadias in Texas and 5.503% (95% CI, 5.495%-5.511%) of boys with hypospadias in Arkansas have a co-occurring CHD. In addition, hypospadias severity and maternal race and ethnicity were independently associated with the likelihood for hypospadias to co-occur with a CHD; boys in Texas with third-degree (ie, more severe) hypospadias were 2.7 times (95% CI, 2.2-3.4) more likely than boys with first-degree hypospadias to have a co-occurring CHD, with consistent estimates in Arkansas (odds ratio, 2.7; 95% CI, 1.4-5.3), and boys with hypospadias born to Hispanic mothers in Texas were 1.5 times (95% CI, 1.3-1.8) more likely to have a co-occurring CHD than boys with hypospadias born to non-Hispanic White mothers. In this cohort study, boys with hypospadias had a higher prevalence of CHDs than boys without hypospadias. These findings support the need for consideration of additional CHD screening programs for boys born with hypospadias.

Multijurisdictional Analyses of Birth Defects: Considering the Common Data Model Approach.

Multijurisdictional Analyses of Birth Defects: Considering the Common Data Model Approach.

Epidemiological association of cannabinoid- and drug- exposures and sociodemographic factors with limb reduction defects across USA 1989–2016: A geotemporospatial study

BackgroundReports of major limb defects after prenatal cannabis exposure (PCE) in animals and of human populations in Hawaii, Europe and Australia raise the question of whether the increasing use of cannabis in USA might be spatiotemporally associated with limb reduction rates (LRR) across USA. MethodsCongenital anomaly data was from the National Birth Defects Prevention Network, drug use data was taken from the National Survey of Drug Use and Health (NSDUH), cannabinoid concentration was estimated from Federal seizure data and ethnicity and income data were from the US Census bureau. Geotemporospatial analysis was conducted in R. Results436 LRR datapoints were obtained. LRR was significantly associated with cannabis use and tetrahydrocannabinol (THC) exposure and demonstrated prominent cannabis-use quintile effects. A sharp increase in LRR occurred from the fourth to fifth quintiles of cannabis exposure (mean ± S.E.M 3.78 ± 0.38 to 6.66 ± 0.56/10,000 live births, P = 5.22 × 10−9). In final lagged geospatial models adjusted for ethnicity and income interactive terms including cannabinoids were highly significant and robust to adjustment. States in which cannabis was not legalized had a lower LRR (4.28 v 5.01/10,000 live births, relative risk reduction = −0.15, (95%C.I. −0.25, −0.02), P = 0.021). Internationally 37–63% of cases are estimated to not be born alive. Their inclusion in these analyzes uniformly intensified the identified effects and the significance of the effect of the cannabis legalization paradigm rose from P = 0.0256 to P = 0.0146 to P = 0.0048 with silent factors of 0%, 36% and 63%, respectively. ConclusionTherefore a spatiotemporal and dose-dependent association between several cannabinoids including THC and cannabigerol and LRR is reported, is robust to adjustment, is consistent with pathophysiological and preclinical studies, accords with findings elsewhere, is markedly exacerbated in higher exposure quintiles, is exacerbated by cannabis legalization and evidences dose-related intergenerational sequaelae.

Geotemporospatial and causal inference epidemiological analysis of US survey and overview of cannabis, cannabidiol and cannabinoid genotoxicity in relation to congenital anomalies 2001\u20132015

BackgroundCannabinoids including cannabidiol have recognized genotoxic activities but their significance has not been studied broadly epidemiologically across the teratological spectrum. We examined these issues including contextual space-time relationships and formal causal inferential analysis in USA.MethodsState congenital anomaly (CA) rate (CAR) data was taken from the annual reports of the National Birth Defects Prevention Network 2001–2005 to 2011–2015. Substance abuse rates were from the National Survey of Drug Use and Health a nationally representative longitudinal survey of the non-institutionalized US population with 74.1% response rate. Drugs examined were cigarettes, monthly and binge alcohol, monthly cannabis and analgesic and cocaine abuse. Early termination of pregnancy for abortion (ETOPFA) rates were taken from the published literature. Cannabinoid concentrations were from Drug Enforcement Agency. Ethnicity and income data were from the US Census Bureau. Inverse probability weighted (IPW) regressions and geotemporospatial regressions conducted for selected CAs.ResultsData on 18,328,529 births from an aggregated population of 2,377,483,589 for mid-year analyses 2005–2013 comprehending 12,611 CARs for 62 CAs was assembled and ETOPFA-corrected (ETOPFACAR) where appropriate. E-Values for ETOPFACARs by substance trends were elevated for THC (40 CAs), cannabis (35 CAs), tobacco (11 CAs), cannabidiol (8 CAs), monthly alcohol (5 CAs) and binge alcohol (2 CAs) with minimum E-Values descending from 16.55, 1.55x107, 555.10, 7.53x1019, 9.30 and 32.98. Cardiovascular, gastrointestinal, chromosomal, limb reductions, urinary, face and body wall CAs particularly affected. Highest v. lowest substance use quintile CAR prevalence ratios 2.84 (95%C.I. 2.44, 3.31), 4.85 (4.08, 5.77) and 1.92 (1.63, 2.27) and attributable fraction in exposed 0.28 (0.27, 0.28), 0.57 (0.51, 0.62) and 0.47 (0.38, 0.55) for tobacco, cannabis and cannabidiol. Small intestinal stenosis or atresia and obstructive genitourinary defect were studied in detail in lagged IPW pseudo-randomized causal regressions and spatiotemporal models confirmed the causal role of cannabinoids. Spatiotemporal predictive modelling demonstrated strongly sigmoidal non-linear cannabidiol dose-response power-function relationships (P = 2.83x10−60 and 1.61x10−71 respectively).ConclusionsData implicate cannabinoids including cannabidiol in a diverse spectrum of heritable CAs. Sigmoidal non-linear dose-response relationships are of grave concern.These transgenerational genotoxic, epigenotoxic, chromosomal-toxic putatively causal teratogenic effects strongly indicate tight restrictions on community cannabinoid penetration.

Issue Information

Birth Defects ResearchVolume 114, Issue 2 p. 29-32 ISSUE INFORMATIONFree Access Issue Information First published: 27 January 2022 https://doi.org/10.1002/bdr2.1906AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume114, Issue2Special Issue: National Birth Defects Prevention Network (NBDPN)January 15, 2022Pages 29-32 RelatedInformation

Epidemiological overview of multidimensional chromosomal and genome toxicity of cannabis exposure in congenital anomalies and cancer development

Cannabis and cannabinoids are implicated in multiple genotoxic, epigenotoxic and chromosomal-toxic mechanisms and interact with several morphogenic pathways, likely underpinning previous reports of links between cannabis and congenital anomalies and heritable tumours. However the effects of cannabinoid genotoxicity have not been assessed on whole populations and formal consideration of effects as a broadly acting genotoxin remain unexplored. Our study addressed these knowledge gaps in USA datasets. Cancer data from CDC, drug exposure data from National Survey of Drug Use and Health 2003–2017 and congenital anomaly data from National Birth Defects Prevention Network were used. We show that cannabis, THC cannabigerol and cannabichromene exposure fulfill causal criteria towards first Principal Components of both: (A) Down syndrome, Trisomies 18 and 13, Turner syndrome, Deletion 22q11.2, and (B) thyroid, liver, breast and pancreatic cancers and acute myeloid leukaemia, have mostly medium to large effect sizes, are robust to adjustment for ethnicity, other drugs and income in inverse probability-weighted models, show prominent non-linear effects, have 55/56 e-Values > 1.25, and are exacerbated by cannabis liberalization (P = 9.67 × 10–43, 2.66 × 10–15). The results confirm experimental studies showing that cannabinoids are an important cause of community-wide genotoxicity impacting both birth defect and cancer epidemiology at the chromosomal hundred-megabase level.

A Comprehensive Review of Intestinal Atresias

A Comprehensive Review of Intestinal Atresias

Prevalence of birth defects among infants with neonatal abstinence syndrome in Illinois, 2015-2016.

Opioid use has reached historically high levels across the United States and infants exposed during pregnancy are at risk of developing a drug withdrawal syndrome called neonatal abstinence syndrome (NAS). The prevalence of birth defects among Illinois infants exhibiting NAS has not been estimated. We linked birth certificate data for Illinois-resident infants born in Illinois in 2015 or 2016 to previously collected NAS and Adverse Pregnancy Outcome Reporting System birth defect data. We examined the prevalence of selected specific birth defects and of newborn infants with one or more of the National Birth Defects Prevention Network's (NBDPN) birth defects, comparing infants with and without NAS. We used logistic regression to estimate the odds ratio for having one or more NBDPN birth defects in infants with and without NAS, after adjusting for other risk factors. Of 302,043 Illinois-resident births, 899 (3.0/1,000 live births) had NAS, and 4,250 (140.7/10,000 live births) had one or more NBDPN birth defect. Infants with an NBDPN birth defect were 1.9 (95% CI [1.3, 2.9]) times more likely to have developed NAS at delivery, and specifically, there was a higher prevalence of ventricular septal defect, club foot, and oral cleft, among infants with NAS when compared to those born without. Elevated prevalence rates and odds ratios add to the growing evidence of an association between NAS and birth defects. Other studies have found similar associations between opioid exposure and the birth defects identified in this analysis.

Capture rate of congenital heart defects in the Pediatric Health Information System database.

Congenital heart defects (CHD) are common and are a frequent subject of research using large administrative databases such as the Pediatric Health Information System (PHIS) database. The capture rate of CHD within PHIS, however, has not been described. The PHIS database includes inpatient encounters from over 52 tertiary care pediatric hospitals across the United States. We identified all patients less than 1 year of age with a cardiac defect in PHIS from 2010 to 2014 and compared these results with national prevalence estimates based on the National Birth Defects Prevention Network annual report, which served as the gold standard. The capture rate of CHD in PHIS ranged from 30 to 95% depending on the spectrum of severity and heterogeneity of the cardiac defect. The capture rate was higher for critical CHD (CCHD) at 66%, and all lesions with 70% or greater capture rate (interrupted aortic arch, truncus arteriosus, single ventricle, total anomalous pulmonary venous return, double outlet right ventricle, and hypoplastic left heart syndrome) fell within the CCHD category. Just over half of the predicted CHD patients were identified using the PHIS database. Although there is a high capture rate for CHD that require early hospitalization, there is a low capture rate for defects with a wider spectrum of disease presentation. These attributes of the PHIS database should be used to frame previous and future research using PHIS to study CHD.

Abstract PR03: Sex ratio disparities and the risk of childhood cancer: Evaluating the mediating effect of birth defects among 15,000 childhood cancer cases

Abstract Background: There is a persistent yet unexplained disparity in the sex ratio among childhood cancer cases, whereby males are more likely to develop several cancers. These patterns are also seen for most birth defects, which are strongly associated with the risk of childhood cancer. We conducted a mediation analysis to estimate whether birth defect status mediates the association between sex and childhood cancer risk. Methods: We linked data from birth, birth defects, and cancer registries to obtain a population-based birth cohort including births from 1992-2013 in Arkansas, Michigan, North Carolina, and Texas. We obtained birth defects diagnoses, including chromosomal and nonchromosomal defects, from statewide, population-based birth defects registries. We focused on “major” defects as defined by the National Birth Defects Prevention Network and the National Birth Defects Prevention Study. Cancer diagnoses that occurred prior to age 18 years were obtained from state cancer registries. We obtained data on child’s sex, birth weight, gestational age, maternal race/ethnicity, maternal age, and plurality from birth records. We conducted counterfactual mediation analysis to estimate the direct and indirect effects of sex on risk of childhood cancer, modeling sex as the exposure, birth defect status as the mediator, and cancer type as the outcome. State, maternal race/ethnicity (white, black, other), maternal age (continuous), and plurality (singleton vs. multiple) were considered potential mediator-outcome confounders. Due to lower success rates of linkage to birth records among adolescent cancer cases, we conducted a sensitivity analysis limiting to cancers diagnosed at age < 5 years. Results: Our dataset included 10,181,074 children (5,208,379 males; 4,972,695 females), including 15,110 with cancer diagnoses (8044 males; 7066 females), 539,567 children with birth defects diagnoses (320,666 males; 218,901 females), and 2,124 co-occurring cases (children with both cancer and one or more birth defect diagnosis: 1,186 males; 938 females). We observed mediation of the association between sex and childhood cancer overall by birth defect status (proportion mediated [PM]: 38%). In analyses of specific cancer types, we observed variation of the estimated proportion mediated among several cancers, including hepatoblastoma (PM: 33%), neuroblastoma (PM: 35%), non-Hodgkin lymphoma (PM: 6%), and soft tissue sarcomas (PM: 25%). In analysis of children age < 5 years at cancer diagnosis, we observed similar results. Conclusions: Our results suggest that birth defects mediate a significant proportion of the overall relationship between sex and childhood cancer. While approximately 60% of the male excess in childhood cancer cases remains unexplained, these findings add to our understanding of the causal pathway of male sex as a risk factor for childhood cancer. Additional studies are under way to characterize the biology underlying these observations. This abstract is also being presented as Poster A66. Citation Format: Erin L. Marcotte, Jeremy M. Schraw, Tania A. Desrosiers, Wendy N. Nembhard, Peter H. Langlois, Mark A. Canfield, Robert E. Meyer, Sharon E. Plon, Philip Lupo. Sex ratio disparities and the risk of childhood cancer: Evaluating the mediating effect of birth defects among 15,000 childhood cancer cases [abstract]. In: Proceedings of the AACR Special Conference on the Advances in Pediatric Cancer Research; 2019 Sep 17-20; Montreal, QC, Canada. Philadelphia (PA): AACR; Cancer Res 2020;80(14 Suppl):Abstract nr PR03.

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

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. 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. 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. 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.

National population-based estimates for major birth defects, 2010-2014.

Using the National Birth Defects Prevention Network (NBDPN) annual data report, U.S. national prevalence estimates for major birth defects are developed based on birth cohort 2010-2014. Data from 39 U.S. population-based birth defects surveillance programs (16 active case-finding, 10 passive case-finding with case confirmation, and 13 passive without case confirmation) were used to calculate pooled prevalence estimates for major defects by case-finding approach. Fourteen active case-finding programs including at least live birth and stillbirth pregnancy outcomes monitoring approximately one million births annually were used to develop national prevalence estimates, adjusted for maternal race/ethnicity (for all conditions examined) and maternal age (trisomies and gastroschisis). These calculations used a similar methodology to the previous estimates to examine changes over time. The adjusted national birth prevalence estimates per 10,000 live births ranged from 0.62 for interrupted aortic arch to 16.87 for clubfoot, and 19.93 for the 12 critical congenital heart defects combined. While the birth prevalence of most birth defects studied remained relatively stable over 15 years, an increasing prevalence was observed for gastroschisis and Down syndrome. Additionally, the prevalence for atrioventricular septal defect, tetralogy of Fallot, omphalocele, and trisomy 18 increased in this period compared to the previous periods. Active case-finding programs generally had higher prevalence rates for most defects examined, most notably for anencephaly, anophthalmia/microphthalmia, trisomy 13, and trisomy 18. National estimates of birth defects prevalence provide data for monitoring trends and understanding the impact of these conditions. Increasing prevalence rates observed for selected conditions warrant further examination.

Exploring classification of birth defects severity in national hospital discharge databases compared to an active surveillance program.

To explore the extent to which the severity of birth defects could be differentiated using severity of illness (SOI) and risk of mortality (ROM) measures available in national discharge databases. Data from the 2012-14 National Inpatient Sample (NIS) was used to identify hospitalizations with one or more major birth defects reported annually to the National Birth Defects Prevention Network using the International Classification of Diseases, Ninth Edition, Clinical Modification (ICD-9-CM) diagnosis codes. Each hospitalization also contained a 4-level SOI and 4-level ROM classification measure. For each birth defect and for each individual birth defect-related ICD-9-CM code, we calculated mean and median SOI and ROM, the proportion of hospitalizations in each level of SOI and ROM, the inpatient mortality rate, and level of agreement between various existing or derived severity proxies in the NIS and the Texas Birth Defects Registry (TBDR). Mean SOI ranged from 1.5 (cleft lip alone) to 3.7 (single ventricle), and mean ROM ranged from 1.1 (cleft lip alone) to 3.9 (anencephaly). As a group, critical congenital heart defects had the highest average number of co-occurring defects, mean SOI, and ROM, whereas orofacial and genitourinary defects had the lowest SOI and ROM. We found strong levels of agreement between TBDR severity classifications and NIS severity classifications defined using Level 3 or 4 SOI or ROM Level 3 or 4. This preliminary investigation demonstrated how severity indices of birth defects could be differentiated and compared to a severity algorithm of an existing surveillance program.

Status of population‐based birth defects surveillance programs before and after the Zika public health response in the United States

The 2016 Zika public health response in the United States highlighted the need for birth defect surveillance (BDS) programs to collect population-based data on birth defects potentially related to Zika as rapidly as possible through enhanced case ascertainment and reporting. The National Birth Defects Prevention Network (NBDPN) assessed BDS program activities in the United States before and after the Zika response. The NBDPN surveyed 54 BDS programs regarding activities before and after the Zika response, lessons learned, and programmatic needs. Follow-up emails were sent and phone calls were held for programs with incomplete or no response to the online survey. Survey data were cleaned and tallied, and responses to open-ended questions were placed into best-fit categories. A 100% response rate was achieved. Of the 54 programs surveyed, 42 reported participation in the Zika public health response that included BDS activities. Programs faced challenges in expanding their surveillance effort given the response requirements but reported mitigating factors such as establishing and enhancing partnerships and program experience with surveillance and clinical activities. Beyond funding, reported program needs included training, surveillance tools/resources, and availability of clinical experts. Existing BDS programs with experience implementing active case-finding and case verification were able to adapt their surveillance efforts rapidly to collect and report data necessary for the Zika response. Program sustainability for BDS remains challenging; thus, continued support, training, and resource development are important to ensure that the infrastructure built during the Zika response is available for the next public health response.

Population-based birth defects data in the United States, 2010-2014: A focus on gastrointestinal defects.

Gastrointestinal defects are a phenotypically and etiologically diverse group of malformations. Despite their combined prevalence and clinical impact, little is known about the epidemiology of these birth defects. Therefore, the objective of the 2017 National Birth Defects Prevention Network (NBDPN) data brief was to better describe the occurrence of gastrointestinal defects. As part of the 2017 NBDPN annual report, 28 state programs provided additional data on gastrointestinal defects for the period 2010-2014. Counts and prevalence estimates (per 10,000 live births) were calculated overall and by demographic characteristics for (1) biliary atresia; (2) esophageal atresia/tracheoesophageal fistula; (3) rectal and large intestinal atresia/stenosis; and (4) small intestinal atresia/stenosis. Additionally, we explored the frequency of these malformations co-occurring with other structural birth defects. Pooling data from all participating registries, the prevalence estimates were: 0.7 per 10,000 live births for biliary atresia (713 cases); 2.3 per 10,000 live births for esophageal atresia/tracheoesophageal fistula (2,472 cases); 4.2 per 10,000 live births for rectal and large intestinal atresia/stenosis (4,334 cases); and 3.4 per 10,000 live births for small intestinal atresia/stenosis (3,388 cases). Findings related to co-occurring birth defects were especially notable for esophageal atresia/tracheoesophageal fistula, rectal and large intestinal atresia/stenosis, and small intestinal atresia/stenosis, where the median percentage of non-isolated cases was 53.9%, 45.5%, and 50.6%, respectively. These population-based prevalence estimates confirm some previous studies, and provide a foundation for future epidemiologic studies of gastrointestinal defects. Exploring the genetic and environmental determinants of these malformations may yield new clues into their etiologies.