Classification of isolated versus multiple birth defects: An automated process for population-based registries

Epidemiologic studies of birth defects often conduct separate analyses for cases that have isolated defects (e.g., spina bifida only) and cases that have multiple defects (e.g., spina bifida and a congenital heart defect). However, in some instances, cases with additional defects (e.g., spina bifida and clubfoot) may be more appropriately considered as isolated because the co-occurring defect (clubfoot) is believed to be developmentally related to the defect of interest. Determining which combinations should be considered isolated can be challenging and potentially resource intensive for registries. Thus, we developed automated classification procedures for differentiating between isolated versus multiple defects, while accounting for developmentally related defects, and applied the approach to data from the Texas Birth Defects Registry (1999-2018 deliveries). Among 235,544 nonsyndromic cases in Texas, 89% of cases were classified as having isolated defects, with proportions ranging from 25% to 92% across 43 specific defects analyzed. A large proportion of isolated cases with spina bifida (44%), lower limb reduction defects (44%), and holoprosencephaly (32%) had developmentally related defects. Overall, our findings strongly support the need to account for isolated versus multiple defects in risk factor association analyses and to account for developmentally related defects when doing so, which has implications for interpreting prior studies.

Gastroschisis prevalence patterns in 27 surveillance programs from 24 countries, International Clearinghouse for Birth Defects Surveillance and Research, 1980-2017

BACKGROUND

Gastroschisis is a serious birth defect with midgut prolapse into the amniotic cavity. The objectives of this study were to evaluate the prevalence and time trends of gastroschisis among programs in the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR), focusing on regional variations and maternal age changes in the population.

METHODS

We analyzed data on births from 1980 to 2017 from 27 ICBDSR member programs, representing 24 countries and three regions (Europe+ (includes Iran) , Latin America, North America). Cases were identified using diagnostic codes (i.e., 756.7, 756.71, or Q79.3). We excluded cases of amniotic band syndrome, limb-body wall defect, and ruptured omphalocele. Programs provided annual counts for gastroschisis cases (live births, stillbirths, and legally permitted pregnancy terminations for fetal anomalies) and source population (live births, stillbirths), by maternal age.

RESULTS

Overall, gastroschisis occurred in 1 of every 3268 births (3.06 per 10,000 births; 95% confidence intervals [CI]: 3.01, 3.11), with marked regional variation. European+ prevalence was 1.49 (95%CI: 1.44, 1.55), Latin American 3.80 (95%CI: 3.69, 3.92) and North American 4.32 (95%CI: 4.22, 4.42). A statistically significant increasing time trend was observed among six European+ , four Latin American, and four North American programs. Women <20 years of age had the highest prevalence in all programs except the Slovak Republic.

CONCLUSIONS

Gastroschisis prevalence increased over time in 61% of participating programs, and the highest increase in prevalence was observed among the youngest women. Additional inquiry will help to assess the impact of the changing maternal age proportions in the birth population on gastroschisis prevalence.

Pediatric cancer incidence among individuals with overgrowth syndromes and overgrowth features: A population-based assessment in seven million children

BACKGROUND

Overgrowth syndromes (e.g., Beckwith-Wiedemann) are associated with an increased risk of pediatric cancer, although there are few population-based estimates of risk. There are also limited studies describing associations between other overgrowth features (e.g., hepatosplenomegaly) and pediatric cancer. Therefore, cancer risk among children with these conditions was evaluated with data from a large, diverse population-based registry linkage study.

METHODS

This study includes all live births in Texas during the years 1999-2017. Children with overgrowth features and syndromes were identified from the Texas Birth Defects Registry; children with cancer were identified by linkage to the Texas Cancer Registry. Cox regression models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between each overgrowth syndrome/feature and cancer, which were adjusted for infant sex and maternal age.

RESULTS

In the total birth cohort (n = 6,997,422), 21,207 children were identified as having an overgrowth syndrome or feature. Children with Beckwith-Wiedemann syndrome were 42 times more likely to develop pediatric cancer (95% CI, 24.20-71.83), with hepatoblastoma being the most common, followed by Wilms tumor. The presence of any isolated overgrowth feature was associated with increased cancer risk (HR, 4.70; 95% CI, 3.83-5.77); associations were strongest for hepatosplenomegaly (HR, 23.04; 95% CI, 13.37-39.69) and macroglossia (HR, 11.18; 95% CI, 6.35-19.70).

CONCLUSIONS

This population-based assessment confirmed prior findings that children with either overgrowth syndromes or features were significantly more likely to develop cancer. Overall, this study supports recommendations for cancer surveillance in children with these conditions and may also inform future research into cancer etiology.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

An epidemiologic study of penoscrotal transposition by maternal characteristics using data from the Texas birth defects registry

BACKGROUND

Penoscrotal transposition (PST) is an uncommon urogenital malformation in which the penis is mal-positioned to be inferior to the scrotum. The purpose of this study was to explore PST risk by maternal characteristics and to describe co-occurring congenital abnormalities in the Texas Birth Defects Registry (TBDR).

METHODS

We conducted a population-based descriptive study examining occurrence of PST in the TBDR between 1999 and 2019. The primary outcome variable was PST diagnosis during infancy. Descriptive variables included maternal age, education, and race/ethnicity. Prevalence ratios (PRs) were calculated within each maternal variable category using Poisson regression. Counts and percentages of cases with select co-occurring congenital abnormalities were also calculated.

RESULTS

Overall, 251 infants had PST, providing a prevalence of 0.61/10,000 live male births (95% CI: 0.53-0.68). PST prevalence was significantly lower among infants of mothers who had lower educational attainment (high school), who were younger (<25 vs. 25-34), and who were Hispanic (vs. non-Hispanic White) and was significantly higher among older mothers (35+ vs. 25-39). Hypospadias was the most common co-occurring genitourinary anomaly, affecting close to 70% of cases.

CONCLUSIONS

To our knowledge, this is the first investigation exploring the prevalence of PST in a population-based birth defects registry. Our findings help to understand the risk for PST among select maternal demographic characteristics and may assist in generating hypotheses about the underlying etiology of this condition for future work.

Prevalence of congenital anomalies according to maternal race and ethnicity, Texas, 1999-2018

BACKGROUND

Few studies of congenital anomalies provide prevalence estimates stratified by maternal race/ethnicity. We sought to determine whether the prevalence of a broad spectrum of anomalies varies among offspring of women from different race/ethnic groups.

METHODS

We obtained information on cases with anomalies from the population-based Texas Birth Defects Registry, and denominator data on livebirths among Texas residents during 1999-2018 from the Texas Center for Health Statistics. We estimated the prevalence ratio (PR) and 95% confidence interval (CI) of N = 145 anomalies among offspring of Hispanic and non-Hispanic Black relative to non-Hispanic White women using Poisson regression, adjusting for maternal age, education, body mass index, and previous livebirths. We performed a two-stage analysis with a Bonferroni-adjusted p < 1.7 × 10-4 in the initial screening phase to identify anomalies with statistically significant variation.

RESULTS

There were 7,698,768 livebirths and 1,187,385 anomalies diagnosed in 368,393 cases. The prevalence of any monitored congenital anomaly was similar among offspring of non-Hispanic White (referent), non-Hispanic Black (PR 0.98, CI 0.96-1.00), and Hispanic (PR 0.95, CI 0.93-0.96) women. We observed statistically significant racial/ethnic variation for 42 anomalies. Marked differences were observed when comparing offspring of non-Hispanic Black to non-Hispanic White women with respect to polydactyly (PR 4.38, CI 4.07-4.72), pyloric stenosis (PR 0.34, CI 0.29-0.40), and aortic valve atresia/stenosis (PR 0.51, CI 0.36-0.72).

CONCLUSIONS

Birth prevalence of many major congenital anomalies varies by maternal race and ethnicity. While the reasons for these differences are likely multifactorial, a thorough understanding of racial and ethnic disparities is useful to stimulate etiologic research.

Survival of neonates, infants, and children with birth defects: a population-based study in Texas, 1999-2018

Background

Birth defects are a leading cause of neonatal, infant, and childhood mortality, but recent population-based survival estimates for a spectrum in the U.S. are lacking.

Methods

Using the statewide Texas Birth Defects Registry (1999-2017 births) and vital records linkage to ascertain deaths, we conducted Kaplan-Meier analyses to estimate survival probabilities at 1, 7, and 28 days, and 1, 5, and 10 years. We evaluated survival in the full cohort of infants with any major defect and for 30 specific conditions. One-year survival analyses were stratified by gestational age, birth year, and case classification.

Findings

Among 246,394 live-born infants with any major defect, the estimated survival probabilities were 98.9% at 1 day, 95.0% at 1 year, and 93.9% at 10 years. Ten-year survival varied by condition, ranging from 36.9% for holoprosencephaly to 99.3% for pyloric stenosis. One-year survival was associated with increasing gestational age (e.g., increasing from 46.9% at <28 weeks to 95.8% at ≥37 weeks for spina bifida). One-year survival increased in more recent birth years for several defect categories (e.g., increasing from 86.0% among 1999-2004 births to 93.1% among 2014-2017 births for unilateral renal agenesis/dysgenesis) and was higher among infants with an isolated defect versus those with multiple defects.

Interpretation

This study describes short- and long-term survival outcomes from one of the largest population-based birth defect registries in the world and highlights improved survival over time for several conditions. Our results may lend insight into future healthcare initiatives aimed at reducing mortality in this population.

Funding

This study was funded in part by a Centers for Disease Control and Prevention (CDC) birth defects surveillance cooperative agreement with the Texas Department of State Health Services and Health Resources and Services Administration (HRSA) Block Grant funds.

Associations between birth defects and childhood and adolescent germ cell tumors according to sex, histologic subtype, and site

BACKGROUND

Studies have reported increased rates of birth defects among children with germ cell tumors (GCTs). However, few studies have evaluated associations by sex, type of defect, or tumor characteristics.

METHODS

Birth defect-GCT associations were evaluated among pediatric patients (N = 552) with GCTs enrolled in the Germ Cell Tumor Epidemiology Study and population-based controls (N = 6380) without cancer from the Genetic Overlap Between Anomalies and Cancer in Kids Study. The odds ratio (OR) and 95% confidence interval (CI) of GCTs according to birth defects status were estimated by using unconditional logistic regression. All defects were considered collectively and by genetic and chromosomal syndromes and nonsyndromic defects. Stratification was by sex, tumor histology (yolk sac tumor, teratoma, germinoma, and mixed/other), and location (gonadal, extragonadal, and intracranial).

RESULTS

Birth defects and syndromic defects were more common among GCT cases than controls (6.9% vs. 4.0% and 2.7% vs. 0.2%, respectively; both p < .001). In multivariable models, GCT risk was increased among children with birth defects (OR, 1.7; 95% CI, 1.3-2.4) and syndromic defects (OR, 10.4; 95% CI, 4.9-22.1). When stratified by tumor characteristics, birth defects were associated with yolk sac tumors (OR, 2.7; 95% CI, 1.3-5.0) and mixed/other histologies (OR, 2.1; 95% CI, 1.2-3.5) and both gonadal tumors (OR, 1.7; 95% CI, 1.0-2.7) and extragonadal tumors (OR, 3.8; 95% CI, 2.1-6.5). Nonsyndromic defects specifically were not associated with GCTs. In sex-stratified analyses, associations were observed among males but not females.

CONCLUSIONS

These data suggest that males with syndromic birth defects are at an increased risk of pediatric GCTs, whereas males with nonsyndromic defects and females are not at an increased risk.

PLAIN LANGUAGE SUMMARY

We investigated whether birth defects (such as congenital heart disease or Down syndrome) are linked to childhood germ cell tumors (GCTs), cancers that mainly develop in the ovaries or testes. We studied different types of birth defects (defects that were caused by chromosome changes such as Down syndrome or Klinefelter syndrome and defects that were not) and different types of GCTs. Only chromosome changes such as Down syndrome or Klinefelter syndrome were linked to GCTs. Our study suggests that most children with birth defects are not at an increased risk of GCTs because most birth defects are not caused by chromosome changes.

Prediction of Preterm Birth among Infants with Orofacial Cleft Defects

OBJECTIVE

To develop risk prediction models for preterm birth among infants with orofacial clefts.

DESIGN

Data from the Texas Birth Defects Registry for infants with orofacial clefts born between 1999-2014 were used to develop preterm birth predictive models. Logistic regression was used to consider maternal and infant characteristics, and internal validation of the final model was performed using bootstrapping methods. The area under the curve (AUC) statistic was generated to assess model performance, and separate predictive models were built and validated for infants with cleft lip and cleft palate alone. Several secondary analyses were conducted among subgroups of interest.

SETTING

State-wide, population-based Registry data.

PATIENTS/PARTICIPANTS

6774 infants with orofacial clefts born in Texas between 1999-2014.

MAIN OUTCOME MEASURE(S)

Preterm birth among infants with orofacial clefts.

RESULTS

The final predictive model performed modestly, with an optimism-corrected AUC of 0.67 among all infants with orofacial clefts. The optimism-corrected models for cleft lip (with or without cleft palate) and cleft palate alone had similar predictive capability, with AUCs of 0.66 and 0.67, respectively. Secondary analyses had similar results, but the model among infants with delivery prior to 32 weeks demonstrated higher optimism-corrected predictive capability (AUC = 0.74).

CONCLUSIONS

This study provides a first step towards predicting preterm birth risk among infants with orofacial clefts. Identifying pregnancies affected by orofacial clefts at the highest risk for preterm birth may lead to new avenues for improving outcomes among these infants.

Epidemiology of Nonsyndromic, Orofacial Clefts in Texas: Differences by Cleft Type and Presence of Additional Defects

To describe the current epidemiology of nonsyndromic cleft palate alone (CP) and cleft lip with or without cleft palate (CL ± P) in Texas and examine differences in the characteristics of infants with CP and CL ± P based on the presence/absence of additional defects.

We used data from the Texas Birth Defects Registry, a statewide active birth defect surveillance system, from 1815 cases with CP and 5066 with CL ± P, without a syndrome diagnosis (1999-2014 deliveries). All live births in Texas were used for comparison. Poisson regression was used to calculate crude and adjusted prevalence ratios (aPR) for each characteristic, separately for each cleft subphenotype.

The prevalence of CL ± P and CP in our study was estimated as 8.3 and 3.0 per 10 000 live births, respectively. After adjusting for several characteristics, several factors were associated with CL ± P, CP, or both, including infant sex and maternal race/ethnicity, age, smoking, and diabetes. There were several differences between infants with isolated versus nonisolated clefts. For example, maternal prepregnancy diabetes was associated with an increased prevalence of CL ± P (aPR 7.91, 95% confidence interval [CI]: 5.53, 11.30) and CP (aPR 3.24, 95% CI: 1.43, 7.36), but only when additional defects were present.

Findings from this study provide a contemporary description of the distribution of orofacial clefts in Texas accounting for differences between isolated and nonisolated clefts. They may contribute to increasing our understanding of the etiology of CP and CL ± P.

Exome-wide assessment of isolated biliary atresia: A report from the National Birth Defects Prevention Study using child-parent trios and a case-control design to identify novel rare variants

The etiology of biliary atresia (BA) is unknown, but recent studies suggest a role for rare protein-altering variants (PAVs). Exome sequencing data from the National Birth Defects Prevention Study on 54 child-parent trios, one child-mother duo, and 1513 parents of children with other birth defects were analyzed. Most (91%) cases were isolated BA. We performed (1) a trio-based analysis to identify rare de novo, homozygous, and compound heterozygous PAVs and (2) a case-control analysis using a sequence kernel-based association test to identify genes enriched with rare PAVs. While we replicated previous findings on PKD1L1, our results do not suggest that recurrent de novo PAVs play important roles in BA susceptibility. In fact, our finding in NOTCH2, a disease gene associated with Alagille syndrome, highlights the difficulty in BA diagnosis. Notably, IFRD2 has been implicated in other gastrointestinal conditions and warrants additional study. Overall, our findings strengthen the hypothesis that the etiology of BA is complex.

Patterns of co-occurring birth defects in children with anotia and microtia

Many infants with anotia or microtia (A/M) have co-occurring birth defects, although few receive syndromic diagnoses in the perinatal period. Evaluation of co-occurring birth defects in children with A/M could identify patterns indicative of undiagnosed/unrecognized syndromes. We obtained information on co-occurring birth defects among infants with A/M for delivery years 1999-2014 from the Texas Birth Defects Registry. We calculated observed-to-expected ratios (OER) to identify birth defect combinations that occurred more often than expected by chance. We excluded children diagnosed with genetic or chromosomal syndromes from analyses. Birth defects and syndromes/associations diagnosed ≤1 year of age were considered. We identified 1310 infants with non-syndromic A/M, of whom 38% (N = 492) were diagnosed with co-occurring major defects. Top combinations included: hydrocephalus, ventricular septal defect, and spinal anomalies (OER 58.4); microphthalmia and anomalies of the aorta (OER 55.4); and cleft lip with or without cleft palate and rib or sternum anomalies (OER 32.8). Some combinations observed in our study may represent undiagnosed/atypical presentations of known A/M associations or syndromes, or novel syndromes yet to be described in the literature. Careful evaluation of infants with multiple birth defects including A/M is warranted to identify individuals with potential genetic or chromosomal syndromes.

Contribution of Preterm Birth to Mortality Among Neonates with Birth Defects

OBJECTIVE

To estimate the proportion of neonatal mortality risk attributable to preterm delivery among neonates with birth defects.

STUDY DESIGN

Using a statewide cohort of live born infants from the Texas Birth Defects Registry (1999-2014 deliveries), we estimated the population attributable fraction and 95% CI of neonatal mortality (death <28 days) attributable to prematurity (birth at <37 weeks vs ≥37 weeks) for 31 specific birth defects. To better understand the overall population burden, analyses were repeated for all birth defects combined.

RESULTS

Our analyses included 169 148 neonates with birth defects, of which 40 872 (24.2%) were delivered preterm. The estimated proportion of neonatal mortality attributable to prematurity varied by birth defect, ranging from 12.5% (95% CI: 8.7-16.1) for hypoplastic left heart syndrome to 71.9% (95% CI: 41.1-86.6) for anotia or microtia. Overall, the proportion was 51.7% (95% CI: 49.4-54.0) for all birth defects combined.

CONCLUSIONS

A large proportion of deaths among neonates with birth defects are attributable to preterm delivery. Our results highlight differences in this burden across common birth defects. Our findings may be helpful for prioritizing future work focused on better understanding the etiology of prematurity among neonates with birth defects and the mechanisms by which prematurity contributes to neonatal mortality in this population.

Prevalence and mortality among children with anorectal malformation: A multi-country analysis

PURPOSE

We examined the total prevalence, trends in prevalence, and age-specific mortality among individuals with anorectal malformation (ARM) METHODS: We conducted a retrospective cohort study using data from 24 population- and hospital-based birth defects surveillance programs affiliated with the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) from 18 countries and for births from 1974 to 2014. We estimated pooled and program-specific total prevalence per 10,000 total births. Poisson regression was used to assess time trends in prevalence from 2001 to 2012 when most programs contributed data. We calculated selected age-specific proportions of deaths, stratified by case status RESULTS: The pooled total prevalence of ARM was 3.26 per 10,000 total births (95% Confidence Interval = 3.19, 3.32) for birth years 1974-2014. About 60% of cases were multiple or syndromic. Prevalence of multiple, syndromic, and stillborn cases decreased from 2001 to 2012. The first week mortality proportion was 12.5%, 3.2%, 28.3%, and 18.2% among all, isolated, multiple, and syndromic cases, respectively CONCLUSIONS: ARM is relatively rare, with multiple and syndromic cases showing decreasing prevalence during the study period. Mortality is a concern during the first week of life, and especially among multiple and syndromic cases. Our descriptive epidemiological findings increase our understanding of geographic variation in the prevalence of ARM and can be used to plan needed clinical services. Exploring factors influencing prevalence and mortality among individuals with ARM could inform future studies.

Survival of infants and children born with severe microcephaly, Texas, 1999-2015

BACKGROUND

Severe microcephaly is a brain reduction defect where the delivery head circumference is <3rd percentile for gestational age and sex with subsequent lifelong morbidities. Our objective was to evaluate survival among 2,704 Texas infants with severe microcephaly delivered 1999-2015.

METHODS

Infants with severe microcephaly from the Texas Birth Defects Registry were linked to death certificates and the national death index. Survival estimates, hazard ratios (HR) and confidence intervals (CI) were calculated using the Kaplan-Meier method and Cox proportional hazards models stratified by presence versus absence of co-occurring defects.

RESULTS

We identified 496 deaths by age 4 years; most (42.9%) occurred in the neonatal period, and another 39.9% died by 1 year of age. Overall infant survival was 84.8%. Lowest infant survival subgroups included those with chromosomal/syndromic conditions (66.1%), very preterm deliveries (63.9%), or co-occurring critical congenital heart defects (44.0%). Among infants with severe microcephaly and a chromosomal/syndromic co-occurring defect, the risk of death was nearly three-fold higher among those with: proportionate microcephaly (i.e., small baby overall), relative to non-proportionate (HR = 2.84, 95% CI = 2.17-3.71); low-birthweight relative to normal (HR = 2.72, 95% CI = 1.92-3.85); critical congenital heart defects (CCHD) relative to no CCHD (HR = 2.90, 95% CI = 2.20-3.80). Trisomies were a leading underlying cause of death (27.5%).

CONCLUSIONS

Overall, infants with severe microcephaly had high 4-year survival rates which varied by the presence of co-occurring defects. Infants with co-occurring chromosomal/syndromic anomalies have a higher risk of death by age one than those without any co-occurring birth defects.

Connecting children with birth defects to health and social service programs: A collaboration between the Texas Birth Defects Registry and agency social workers

BACKGROUND

Timely referral to services for children born with birth defects can improve health outcomes. Birth defects surveillance registries may be a valuable data source for connecting children to health and social service programs.

METHODS

Population-based, state-wide data from the Texas Birth Defects Registry (TBDR) at the Texas Department of State Health Services (DSHS) were used to connect children 9-18 months old, born with select birth defects with DSHS social workers. The social workers reviewed developmental milestones and referred children and their families to various health and social service programs. We tabulated the proportions of children meeting milestones and referral characteristics by referral program type and type of birth defect.

RESULTS

Social workers reached 67% (909/1,362) of identified families. Over half of children (54%, 488/909) were not meeting the developmental milestones for their age. Social workers provided over 3,000 program referrals, including referring 21% (194/909) of children to Early Childhood Intervention (ECI) and 28% (257/909) to case management.

CONCLUSION

Our results illustrate a method of leveraging a birth defects surveillance system for referral services. Given the large number of referrals made, our findings suggest that birth defects registries can be a valuable source of data for referring children to programs.

Evaluating the proportion of isolated cases among a spectrum of birth defects in a population-based registry

INTRODUCTION

Because the etiology and outcomes of birth defects may differ by the presence vs. absence of co-occurring anomalies, epidemiologic studies often attempt to classify cases into isolated versus non-isolated groupings. This report describes a computer algorithm for such classification and presents results using data from the Texas Birth Defects Registry (TBDR).

METHODS

Each of the 1,041 birth defects coded by the TBDR was classified as chromosomal, syndromic, minor, or "needs review" by a group of three clinical geneticists. A SAS program applied those classifications to each birth defect in a case (child/fetus), and then hierarchically combined them to obtain one summary classification for each case, adding isolated and multiple defect categories. The program was applied to 136,121 cases delivered in 2012-2017.

RESULTS

Of total cases, 49% were classified by the platform as isolated (having only one major birth defect). This varied widely by birth defect; of those examined, the highest proportion classified as isolated was found in pyloric stenosis (87.6%), whereas several cardiovascular malformations had low proportions, including tricuspid valve atresia/stenosis (2.3%).

DISCUSSION

This is one of the first and largest attempts to identify the proportion of isolated cases across a broad spectrum of birth defects, which can inform future epidemiologic and genomic studies of these phenotypes. Our approach is designed for easy modification for use with any birth defects coding system and category definitions, allowing scalability for different studies or birth defects registries, which often do not have resources for individual clinical review of all case records.

Factors associated with nonsyndromic anotia and microtia, Texas, 1999-2014

BACKGROUND

Few risk factors have been identified for nonsyndromic anotia/microtia (A/M).

METHODS

We obtained data on cases and a reference population of all livebirths in Texas for 1999-2014 from the Texas Birth Defects Registry (TBDR) and Texas vital records. We estimated prevalence ratios (PRs) and 95% confidence intervals (CIs) for A/M (any, isolated, nonisolated, unilateral, and bilateral) using Poisson regression. We evaluated trends in prevalence rates using Joinpoint regression.

RESULTS

We identified 1,322 cases, of whom 982 (74.3%) had isolated and 1,175 (88.9%) had unilateral A/M. Prevalence was increased among males (PR: 1.3, 95% CI: 1.2-1.4), offspring of women with less than high school education (PR: 1.3, 95% CI: 1.1-1.5), diabetes (PR: 2.0, 95% CI: 1.6-2.4), or age 30-39 versus 20-29 years (PR: 1.2, 95% CI: 1.0-1.3). The prevalence was decreased among offspring of non-Hispanic Black versus White women (PR: 0.6, 95% CI: 0.4-0.8) but increased among offspring of Hispanic women (PR: 2.9, 95% CI: 2.5-3.4) and non-Hispanic women of other races (PR: 1.7, 95% CI: 1.3-2.3). We observed similar results among cases with isolated and unilateral A/M. Sex disparities were not evident for nonisolated or bilateral phenotypes, nor did birth prevalence differ between offspring of non-Hispanic Black and non-Hispanic White women. Maternal diabetes was more strongly associated with nonisolated (PR: 4.5, 95% CI: 3.2-6.4) and bilateral A/M (PR: 5.0, 95% CI: 3.3-7.7). Crude prevalence rates increased throughout the study period (annual percent change: 1.82).

CONCLUSION

We identified differences in the prevalence of nonsyndromic A/M by maternal race/ethnicity, education, and age, which may be indicators of unidentified social/environmental risk factors.

Identifying syndromes in studies of structural birth defects: Guidance on classification and evaluation of potential impact

Structural birth defects that occur in infants with syndromes may be etiologically distinct from those that occur in infants in whom there is not a recognized pattern of malformations; however, population-based registries often lack the resources to classify syndromic status via case reviews. We developed criteria to systematically identify infants with suspected syndromes, grouped by syndrome type and level of effort required for syndrome classification (e.g., text search). We applied this algorithm to the Texas Birth Defects Registry (TBDR) to describe the proportion of infants with syndromes delivered during 1999-2014. We also developed a bias analysis tool to estimate the potential percent bias resulting from including infants with syndromes in studies of risk factors. Among 207,880 cases with birth defects in the TBDR, 15% had suspected syndromes and 85% were assumed to be nonsyndromic, with a range across defect types from 28.5% (atrioventricular septal defects) to 98.9% (pyloric stenosis). Across hypothetical scenarios varying expected parameters (e.g., nonsyndromic proportion), the inclusion of syndromic cases in analyses resulted in up to 50.0% bias in prevalence ratios. In summary, we present a framework for identifying infants with syndromic conditions; implementation might harmonize syndromic classification across registries and reduce bias in association estimates.

The risks of birth defects and childhood cancer with conception by assisted reproductive technology

STUDY QUESTION

Is there an association between fertility status, method of conception and the risks of birth defects and childhood cancer?

SUMMARY ANSWER

The risk of childhood cancer had two independent components: (i) method of conception and (ii) presence, type and number of birth defects.

WHAT IS KNOWN ALREADY

The rarity of the co-occurrence of birth defects, cancer and ART makes studying their association challenging. Prior studies have indicated that infertility and ART are associated with an increased risk of birth defects or cancer but have been limited by small sample size and inadequate statistical power, failure to adjust for or include plurality, differences in definitions and/or methods of ascertainment, lack of information on ART treatment parameters or study periods spanning decades resulting in a substantial historical bias as ART techniques have improved.

STUDY DESIGN, SIZE, DURATION

This was a population-based cohort study linking ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 1 January 2004 to 31 December 2017 that resulted in live births in 2004-2018 in Massachusetts and North Carolina and live births in 2004-2017 in Texas and New York. A 10:1 sample of non-ART births were chosen within the same time period as the ART birth. Non-ART siblings were identified through the ART mother's information. Children from non-ART births were classified as being born to women who conceived with ovulation induction or IUI (OI/IUI) when there was an indication of infertility treatment on the birth certificate, and the woman did not link to the SART CORS; all others were classified as being naturally conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population included 165 125 ART children, 31 524 non-ART siblings, 12 451 children born to OI/IUI-treated women and 1 353 440 naturally conceived children. All study children were linked to their respective State birth defect registries to identify major defects diagnosed within the first year of life. We classified children with major defects as either chromosomal (i.e. presence of a chromosomal defect with or without any other major defect) or nonchromosomal (i.e. presence of a major defect but having no chromosomal defect), or all major defects (chromosomal and nonchromosomal), and calculated rates per 1000 children. Logistic regression models were used to generate adjusted odds ratios (AORs) and 95% CIs of the risk of birth defects by conception group (OI/IUI, non-ART sibling and ART by oocyte source and embryo state) with naturally conceived children as the reference, adjusted for paternal and maternal ages; maternal race and ethnicity, education, BMI, parity, diabetes, hypertension; and for plurality, infant sex and State and year of birth. All study children were also linked to their respective State cancer registries. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs of cancer by birth defect status (including presence of a defect, type and number of defects), and conception group.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 29 571 singleton children (2.0%) and 3753 twin children (3.5%) had a major birth defect (chromosomal or nonchromosomal). Children conceived with ART from autologous oocytes had increased risks for nonchromosomal defects, including blastogenesis, cardiovascular, gastrointestinal and, for males only, genitourinary defects, with AORs ranging from 1.22 to 1.85; children in the autologous-fresh group also had increased risks for musculoskeletal (AOR 1.28, 95% CI 1.13, 1.45) and orofacial defects (AOR 1.40, 95% CI 1.17, 1.68). Within the donor oocyte group, the children conceived from fresh embryos did not have increased risks in any birth defect category, whereas children conceived from thawed embryos had increased risks for nonchromosomal defects (AOR 1.20, 95% CI 1.03, 1.40) and blastogenesis defects (AOR 1.74, 95% CI 1.14, 2.65). The risk of cancer was increased among ART children in the autologous-fresh group (HR 1.31, 95% CI 1.08, 1.59) and non-ART siblings (1.34, 95% CI 1.02, 1.76). The risk of leukemia was increased among children in the OI/IUI group (HR 2.15, 95% CI 1.04, 4.47) and non-ART siblings (HR 1.63, 95% CI 1.02, 2.61). The risk of central nervous system tumors was increased among ART children in the autologous-fresh group (HR 1.68, 95% CI 1.14, 2.48), donor-fresh group (HR 2.57, 95% CI 1.04, 6.32) and non-ART siblings (HR 1.84, 95% CI 1.12, 3.03). ART children in the autologous-fresh group were also at increased risk for solid tumors (HR 1.39, 95% CI 1.09, 1.77). A total of 127 children had both major birth defects and cancer, of which 53 children (42%) had leukemia. The risk of cancer had two independent components: (i) method of conception (described above) and (ii) presence, type and number of birth defects. The presence of nonchromosomal defects increased the cancer risk, greater for two or more defects versus one defect, for all cancers and each type evaluated. The presence of chromosomal defects was strongly associated with cancer risk (HR 8.70 for all cancers and HR 21.90 for leukemia), further elevated in the presence of both chromosomal and nonchromosomal defects (HR 21.29 for all cancers, HR 64.83 for leukemia and HR 4.71 for embryonal tumors). Among the 83 946 children born from ART in the USA in 2019 compared to their naturally conceived counterparts, these risks translate into an estimated excess of 761 children with major birth defects, 31 children with cancer and 11 children with both major birth defects and cancer.

LIMITATIONS, REASONS FOR CAUTION

In the SART CORS database, it was not possible to differentiate method of embryo freezing (slow freezing versus vitrification), and data on ICSI were only available in the fresh embryo ART group. In the OI/IUI group, it was not possible to differentiate type of non-ART treatment utilized, and in both the ART and OI/IUI groups, data were unavailable on duration of infertility. Since OI/IUI is underreported on the birth certificate, some OI/IUI children were likely included among the naturally conceived children, which will decrease the difference between all the groups and the naturally conceived children.

WIDER IMPLICATIONS OF THE FINDINGS

The use of ART is associated with increased risks of major nonchromosomal birth defects. The presence of birth defects is associated with greater risks for cancer, which adds to the baseline risk in the ART group. Although this study does not show causality, these findings indicate that children conceived with ART, non-ART siblings, and all children with birth defects should be monitored more closely for the subsequent development of cancer.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by grant R01 HD084377 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development, or the National Institutes of Health, nor any of the State Departments of Health which contributed data. M.L.E. reports consultancy for Ro, Hannah, Dadi, Sandstone and Underdog; presidency of SSMR; and SMRU board member. The remaining authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Factors associated with Medicaid participation among infants born with birth defects in Texas, 2010-2014

BACKGROUND

Birth defects are major contributors to healthcare resource use, disability, and mortality, particularly during the perinatal period. As the nation's public insurance program for low-income individuals, Medicaid funds a large proportion of healthcare costs associated with birth defects. Here, we explore birth defect-related factors associated with Medicaid participation in the first year of life.

METHODS

Infants born with birth defects between 2010 and 2014 were linked from the Texas Birth Defects Registry to the state's Medicaid claims database. Variation in Medicaid participation was examined by individual birth defect and by birth defect characteristics. The associations between covariates and Medicaid participation are described using percentages and adjusted prevalence ratios (APR).

RESULTS

Of the 107,968 infants included in this study, 55,172 (51.1%) participated in Medicaid. Medicaid participation ranged from 12.1% for anencephaly to 77.8% for total anomalous pulmonary venous connection. An indicator of defect severity was associated with an increased likelihood of participation (APR = 1.22, 95% CI: 1.20-1.23). Medicaid participation was 60.8% for individuals with multiple major defects, compared with 45.4% for those without (APR = 1.24, 95% CI: 1.22-1.25). Among individual birth defects, Medicaid participation was almost universally higher for those co-occurring with other major defects.

CONCLUSIONS

We detected large variations in Medicaid participation by individual birth defect. Infants participating in Medicaid tended to have more severe defects and were more likely to have multiple major defects. Medicaid claims databases can serve as valuable sources of data for surveillance efforts and observational studies, but care should be taken when generalizing findings.

Associations between maternal reports of periconceptional fever from miscellaneous causes and structural birth defects

BACKGROUND

Associations between birth defects and fevers attributed to colds, influenza, and urinary tract infections (UTIs) have been observed in previous studies. Our aim was to study associations between birth defects and fevers attributed to other causes.

METHODS

We analyzed data from 34,862 participants in the National Birth Defects Prevention Study, a multistate case-control study of major structural birth defects. Using multivariable logistic regression, we assessed the association between maternal report of fever during early pregnancy due to causes other than colds, influenza, or UTI and 36 categories of birth defects.

RESULTS

Maternal reports of fever due to other causes were associated with significantly elevated odds ratios ranging from 1.93 to 10.60 for 8 of 36 birth defects, primarily involving the spine, limbs, and heart (spina bifida, intestinal atresia, intercalary limb deficiency, transverse limb deficiency, congenital heart defect with heterotaxy, tetralogy of Fallot, pulmonary atresia and atrial septal defect, not otherwise specified).

CONCLUSION

Our data suggests fever itself or other physiologic changes associated with many infections are associated with some birth defects. Women who are pregnant or planning to become pregnant may want to consider speaking with their healthcare provider about the best ways to avoid infections that may cause fever and for guidance on how to treat fevers during pregnancy.

The Epidemiology of Biliary Atresia: Exploring the Role of Developmental Factors on Birth Prevalence

OBJECTIVE

To identify key epidemiologic factors relevant to fetal development that are associated with biliary atresia.

STUDY DESIGN

This population-based registry study examined infants born in Texas between 1999 and 2014. Epidemiologic data relevant to fetal development were compared between cases of biliary atresia identified in the Texas Birth Defects Registry (n = 305) vs all live births (n = 4 689 920), and Poisson regression was used to calculate prevalence ratios (PRs) and 95% CIs.

RESULTS

The prevalence of biliary atresia over the study period was 0.65 per 10 000 live births. Biliary atresia was positively associated with female sex (adjusted PR, 1.68; 95% CI, 1.33-2.12), delivery before 32-37 weeks of gestation (adjusted PR, 1.64; 95% CI, 1.18-2.29), delivery before 32 weeks of gestation (adjusted PR, 3.85; 95% CI, 2.38-6.22), and non-Hispanic Black vs non-Hispanic White maternal race/ethnicity (adjusted PR, 1.54, 95% CI, 1.06-2.24), while biliary atresia was inversely associated with season of conception in the fall relative to spring (adjusted PR, 0.62; 95% CI, 0.45-0.86). In addition, biliary atresia was associated with maternal diabetes (adjusted PR, 2.34; 95% CI, 1.57-3.48), with a stronger association with pregestational diabetes compared with gestational diabetes. In subgroup analyses, these associations were present in isolated biliary atresia cases that do not have any additional birth defects.

CONCLUSIONS

Biliary atresia is associated with multiple factors related to fetal development, including pregestational maternal diabetes, female sex, and preterm birth. These associations also were observed in isolated cases of biliary atresia without other malformations or laterality defects. Our results are consistent with early life events influencing the pathogenesis of biliary atresia, and support further studies investigating in utero events to better understand etiology and time of onset.

Prevalence and Clustering of Congenital Heart Defects Among Boys With Hypospadias

IMPORTANCE

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.

OBJECTIVE

To characterize the risk of major CHDs among boys born with hypospadias.

DESIGN, SETTING, AND PARTICIPANTS

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.

EXPOSURE

Hypospadias.

MAIN OUTCOMES AND MEASURES

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.

RESULTS

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.

CONCLUSIONS AND RELEVANCE

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.

Abstract 1998: A population-based assessment of cancer risk in children with recurrent multiple congenital anomalies

Purpose: There is emerging evidence that children with multiple congenital anomalies have a higher risk of developing cancer compared to unaffected children. However, there have been few population-based estimates of cancer risk among children with well-described patterns of recurrent multiple congenital anomalies (MCAs). VACTERL association is one such pattern that is defined by the presence of ≥3 of the following in the absence of a genetic diagnosis: vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal, and limb anomalies. VACTERL occurs in approximately 5% of children with Fanconi anemia (FA), a known cancer predisposition syndrome. In spite of this, there are no population-based estimates of cancer risk in children with VACTERL. Therefore, we investigated if VACTERL confers an elevated risk of pediatric cancer by examining a birth cohort of &gt;7 million children from three U.S. states (Texas, North Carolina, and Oklahoma) for the period 1997-2013.

Methods: Demographic and diagnostic data from birth certificates, birth defects registries, and cancer registries were linked in each state and pooled for analysis. For this analysis, children with chromosomal anomalies were excluded. We used Cox proportional hazards models to evaluate the risk of cancer before 19 years of age in three birth defect groups: (1) VACTERL; (2) ≥3 major anomalies but not VACTERL; and (3) 1 to 2 major anomalies. A hazard ratio (HR) and 95% confidence interval (CI) was calculated in each group for: (1) overall cancer risk and (2) risk of embryonal tumors (e.g., neuroblastoma, medulloblastoma, hepatoblastoma) based on reported associations between birth defects and these pediatric cancers.

Results: In our cohort of 7,767,786 births, we identified: 2,090 children (0.02%) with VACTERL; 32,558 children with ≥3 non-VACTERL defects; and 201,871 children with 1 to 2 defects. Respectively, these three groups had 10, 167, and 684 cases of cancer. Compared to children without birth defects, children with VACTERL (HR=3.9, 95% CI: 2.1 - 7.2), ≥3 non-VACTERL defects (4.2, 3.6 - 4.9), and 1 to 2 defects (2.7, 2.5 - 2.9), were all more likely to develop cancer. Risk was higher for embryonal tumors among children with VACTERL (10.4, 4.7 - 23.1) than for those with ≥3 non-VACTERL defects (5.6, 4.2 - 7.4) or 1 to 2 defects (3.9, 3.4 - 4.5).

Conclusion: In this population-based assessment, we demonstrated that children with VACTERL were more likely than other groups to develop cancer, particularly embryonal tumors, although the absolute cancer risk was &lt;1%. Surprisingly, acute myeloid leukemia, a common malignancy among individuals with FA, was not diagnosed in any of the children with VACTERL, suggesting these associations are distinct from FA. These findings demonstrate that VACTERL subtypes and other recurrent MCAs may represent novel cancer predisposition syndromes.

Citation Format: Alexander Renwick, Jeremy M. Schraw, Tania A. Desrosiers, Amanda E. Janitz, Michael E. Scheurer, Mark A. Canfield, Peter H. Langlois, Angela E. Scheuerle, Sharon E. Plon, Philip J. Lupo. A population-based assessment of cancer risk in children with recurrent multiple congenital anomalies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1998.

A Multicountry Analysis of Prevalence and Mortality among Neonates and Children with Bladder Exstrophy

OBJECTIVE

 Bladder exstrophy (BE) is a rare but severe birth defect affecting the lower abdominal wall and genitourinary system. The objective of the study is to examine the total prevalence, trends in prevalence, and age-specific mortality among individuals with BE.

STUDY DESIGN

 We conducted a retrospective cohort study. Data were analyzed from 20 birth defects surveillance programs, members of the International Clearinghouse for Birth Defects Surveillance and Research in 16 countries. Live births, stillbirths, and elective terminations of pregnancy for fetal anomaly (ETOPFA) diagnosed with BE from 1974 to 2014. Pooled and program-specific prevalence of BE per 100,000 total births was calculated. The 95% confidence intervals (CI) for prevalence were estimated using Poisson approximation of binomial distribution. Time trends in prevalence of BE from 2000 to 2014 were examined using Poisson regression. Proportion of deaths among BE cases was calculated on the day of birth, day 2 to 6, day 7 to 27, day 28 to 364, 1 to 4 years, and ≥5 years. Mortality analysis was stratified by isolated, multiple, and syndromic case status.

RESULTS

 The pooled total prevalence of BE was 2.58 per 100,000 total births (95% CI = 2.40, 2.78) for study years 1974 to 2014. Prevalence varied over time with a decreasing trend from 2000 to 2014. The first-week mortality proportion was 3.5, 17.3, and 14.6% among isolated, multiple, and syndromic BE cases, respectively. The majority of first-week mortality occurred on the first day of life among isolated, multiple, and syndromic BE cases. The proportion of first-week deaths was higher among cases reported from programs in Latin America where ETOPFA services were not available.

CONCLUSIONS

 Prevalence of BE varied by program and showed a decreasing trend from 2000 to -2014. Mortality is a concern among multiple and syndromic cases, and a high proportion of deaths among cases occurred during the first week of life.

KEY POINTS

· Total prevalence of BE was 2.58 per 100,000 births.. · Prevalence decreased from 2000 to 2014.. · The first-week mortality was 9.3%..

Analysis of early neonatal case fatality rate among newborns with congenital hydrocephalus, a 2000-2014 multi-country registry-based study

BACKGROUND

Congenital hydrocephalus (CH) comprises a heterogeneous group of birth anomalies with a wide-ranging prevalence across geographic regions and registry type. The aim of the present study was to analyze the early neonatal case fatality rate (CFR) and total birth prevalence of newborns diagnosed with CH.

METHODS

Data were provided by 25 registries from four continents participating in the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) on births ascertained between 2000 and 2014. Two CH rates were calculated using a Poisson distribution: early neonatal CFR (death within 7 days) per 100 liveborn CH cases (CFR) and total birth prevalence rate (BPR) per 10,000 births (including live births and stillbirths) (BPR). Heterogeneity between registries was calculated using a meta-analysis approach with random effects. Temporal trends in CFR and BPR within registries were evaluated through Poisson regression modeling.

RESULTS

A total of 13,112 CH cases among 19,293,280 total births were analyzed. The early neonatal CFR was 5.9 per 100 liveborn cases, 95% confidence interval (CI): 5.4-6.8. The CFR among syndromic cases was 2.7 times (95% CI: 2.2-3.3) higher than among non-syndromic cases (10.4% [95% CI: 9.3-11.7] and 4.4% [95% CI: 3.7-5.2], respectively). The total BPR was 6.8 per 10,000 births (95% CI: 6.7-6.9). Stratified by elective termination of pregnancy for fetal anomalies (ETOPFA), region and system, higher CFR were observed alongside higher BPR rates. The early neonatal CFR and total BPR did not show temporal variation, with the exception of a CFR decrease in one registry.

CONCLUSIONS

Findings of early neonatal CFR and total BPR were highly heterogeneous among registries participating in ICBDSR. Most registries with higher CFR also had higher BPR. Differences were attributable to type of registry (hospital-based vs. population-based), ETOPFA (allowed yes or no) and geographical regions. These findings contribute to the understanding of regional differences of CH occurrence and early neonatal deaths.

Association between maternal smoking and survival among infants with trisomy 21

BACKGROUND

Trisomy 21 (T21) is common, with affected infants having an increased risk of infant mortality (5.9-7.1%). Maternal smoking is associated with infant mortality in the general population, and we evaluated if similar associations were present among infants with T21.

METHODS

We identified infants with T21 from the Texas Birth Defects Registry, and maternal smoking and infant vital status were obtained from linked birth and death certificate data, respectively. Cox proportional hazards regression models were used to calculate hazard ratios between maternal smoking and death between 0 to ≤ 364 days, 28-364 days, and 0-27 days.

RESULTS

We found a significant association between maternal smoking and death between 0 to ≤ 364 (unadjusted HR 1.72, 95% CI 1.07, 2.77), which was no longer statistically significant after adjustment for covariates (adjusted HR 1.55, 95% CI 0.94, 2.56). A similar pattern was observed for death between 28-364 days (adjusted HR: 1.68, 95% CI 0.93, 3.03), whereas the association for 0-27 days (adjusted HR: 1.30, 95% CI 0.51, 3.29) was not statistically significant before and after adjustment.

CONCLUSIONS

The observed magnitudes of associations were similar to previous estimates among the general population. Further work considering the role of other maternal and infant risk factors and social determinants of health is necessary to better understand the observed results.

Birth Defect Co-Occurrence Patterns Among Infants With Cleft Lip and/or Palate

OBJECTIVE

To investigate 2- to 5-way patterns of defects co-occurring with orofacial clefts using data from a population-based registry.

DESIGN

We used data from the Texas Birth Defects Registry for deliveries between 1999 and 2014 to Texas residents, including 1884 cases with cleft palate (CP) and 5289 cases with cleft lip with or without cleft palate (CL±P) without a known syndrome. We identified patterns of defects co-occurring with CP and with CL±P observed more frequently than would be expected if these defects occurred independently. We calculated adjusted observed-to-expected (O/E) ratios to account for the known tendency of birth defects to cluster nonspecifically.

RESULTS

Among infants without a syndrome, 23% with CP and 21% with CL±P had at least 1 additional congenital anomaly. Several combinations of defects were observed much more often than expected. For example, the combination of CL±P, congenital hydrocephaly, anophthalmia, and other nose anomalies had an O/E ratio of 605. For both CP and CL±P, co-occurrence patterns with the highest O/E ratios involved craniofacial and brain abnormalities, and many included the skeletal, cardiovascular, and renal systems.

CONCLUSIONS

The patterns of defects we observed co-occurring with clefts more often than expected may help improve our understanding of the relationships between multiple defects. Further work to better understand some of the top defect combinations could reveal new phenotypic subgroups and increase our knowledge of the developmental mechanisms that underlie the respective defects.

Sixth grade academic achievement among children conceived with IVF: a population-based study in Texas, USA

PURPOSE

To compare academic achievement in reading and mathematics at the end of sixth grade and progress from third to sixth grade by children conceived with in vitro fertilization (IVF) to those conceived naturally.

METHODS

This was a retrospective population-based cohort study of IVF-conceived singleton and twin children who took the 3rd grade and 6th grade public school standardized reading and mathematics testing in Texas.

RESULTS

There were 6623 children with reading scores in both the third and sixth grades and 6374 children with mathematics scores in both the third and sixth grades. Mean (± SE) scaled test scores for IVF and control singleton children for reading were 1544.6 ± 3.4 and 1527.7 ± 1.9, respectively, in third grade and 1701.2 ± 3.6 and 1681.0 ± 2.0, respectively, in sixth grade; for mathematics, the scores were 1564.4 ± 3.7 and 1548.9 ± 2.1, respectively, in third grade and 1774.0 ± 4.2 and 1752.0 ± 2.3, respectively, in sixth grade. In multivariate models, singleton IVF children scored significantly higher than control children in reading and mathematics, averaging 17.7 ± 4.0 points and 20.1 ± 4.1 points higher, respectively, in reading in third and sixth grades and 17.8 ± 4.4 points and 25.0 ± 4.8 points higher, respectively, in mathematics in third and sixth grades.

CONCLUSIONS

Children conceived with IVF and aged 8-9 years and aged 10-12 years performed as well on third and sixth grade reading and mathematics assessments as their counterparts conceived naturally.

Risks of nonchromosomal birth defects, small-for-gestational age birthweight, and prematurity with in vitro fertilization: effect of number of embryos transferred and plurality at conception versus at birth

PURPOSE

Excess embryos transferred (ET) (> plurality at birth) and fetal heartbeats (FHB) at 6 weeks' gestation are associated with reductions in birthweight and gestation, but prior studies have been limited by small sample sizes and limited IVF data. This analysis evaluated associations between excess ET, excess FHB, and adverse perinatal outcomes, including the risk of nonchromosomal birth defects.

METHODS

Live births conceived via IVF from Massachusetts, New York, North Carolina, and Texas included 138,435 children born 2004-2013 (Texas), 2004-2016 (Massachusetts and North Carolina), and 2004-2017 (New York) were classified by ET and FHB. Major birth defects were reported by statewide registries within the first year of life. Logistic regression was used to estimate adjusted odds ratios (AORs) and 95% CIs of the risks of a major nonchromosomal birth defect, small-for-gestational age birthweight (SGA), low birthweight (LBW), and preterm birth (≤36 weeks), by excess ET, and excess ET + excess FHB, by plurality at birth (singletons and twins).

RESULTS

In singletons with [2 ET, FHB =1] and [≥3 ET, FHB=1], risks [AOR (95% CI)] were increased, respectively, for major nonchromosomal birth defects [1.13 (1.00-1.27) and 1.18 (1.00-1.38)], SGA [1.10 (1.03-1.17) and 1.15 (1.05-1.26)], LBW [1.09 (1.02-1.13) and 1.17 (1.07-1.27)], and preterm birth [1.06 (1.00-1.12) and 1.14 (1.06-1.23)]. With excess ET + excess FHB, risks of all adverse outcomes except major nonchromosomal birth defects increased further for both singletons and twins.

CONCLUSION

Excess embryos transferred are associated with increased risks for nonchromosomal birth defects, reduced birthweight, and prematurity in IVF-conceived births.

Patterns of congenital anomalies among individuals with trisomy 13 in Texas

Few population-based studies have analyzed patterns of co-occurring birth defects among those with trisomy 13. We evaluated the frequency of all possible combinations of any one, two, three, or four additional co-occurring birth defects among 736 individuals with trisomy 13 using data from the Texas Birth Defects Registry for deliveries during 1999-2014. We calculated the observed-to-expected ratio for each combination, adjusting for the known tendency for birth defects to cluster non-specifically. To address potential ascertainment differences among live births and non-live births, we repeated analyses specifically among live births. The combination of defects with the largest observed-to-expected ratio was microcephalus, reduction deformities of brain (e.g., holoprosencephaly), anomalies of nose, and polydactyly. As expected, most of the highest 30 observed-to-expected ratios involved combinations with documented features of trisomy 13, including defects of the scalp (e.g., aplasia cutis) and heart. Results were similar among sensitivity analyses restricted to live births. Our findings may help further delineate the phenotypic spectrum for trisomy 13 and may inform future research related to improving screening and counseling for the condition.

Survival of infants born with esophageal atresia among 24 international birth defects surveillance programs

BACKGROUND

Esophageal atresia (EA) affects around 2.3-2.6 per 10,000 births world-wide. Infants born with this condition require surgical correction soon after birth. Most survival studies of infants with EA are locally or regionally based. We aimed to describe survival across multiple world regions.

METHODS

We included infants diagnosed with EA between 1980 and 2015 from 24 birth defects surveillance programs that are members of the International Clearinghouse for Birth Defects Surveillance and Research. We calculated survival as the proportion of liveborn infants alive at 1 month, 1- and 5-years, among all infants with EA, those with isolated EA, those with EA and additional anomalies or EA and a chromosomal anomaly or genetic syndrome. We also investigated trends in survival over the decades, 1980s-2010s.

RESULTS

We included 6,466 liveborn infants with EA. Survival was 89.4% (95% CI 88.1-90.5) at 1-month, 84.5% (95% CI 83.0-85.9) at 1-year and 82.7% (95% CI 81.2-84.2) at 5-years. One-month survival for infants with isolated EA (97.1%) was higher than for infants with additional anomalies (89.7%) or infants with chromosomal or genetic syndrome diagnoses (57.3%) with little change at 1- and 5-years. Survival at 1 month improved from the 1980s to the 2010s, by 6.5% for infants with isolated EA and by 21.5% for infants with EA and additional anomalies.

CONCLUSIONS

Almost all infants with isolated EA survived to 5 years. Mortality was higher for infants with EA and an additional anomaly, including chromosomal or genetic syndromes. Survival improved from the 1980s, particularly for those with additional anomalies.

Maternal Hypertension-Related Genotypes and Congenital Heart Defects

BACKGROUND

Maternal hypertension has been associated with congenital heart defect occurrence in several studies. We assessed whether maternal genotypes associated with this condition were also associated with congenital heart defect occurrence.

METHODS

We used data from the National Birth Defects Prevention Study to identify non-Hispanic white (NHW) and Hispanic women with (cases) and without (controls) a pregnancy in which a select simple, isolated heart defect was present between 1999 and 2011. We genotyped 29 hypertension-related single nucleotide polymorphisms (SNPs). We conducted logistic regression analyses separately by race/ethnicity to assess the relationship between the presence of any congenital heart defect and each SNP and an overall blood pressure genetic risk score (GRS). All analyses were then repeated to assess 4 separate congenital heart defect subtypes.

RESULTS

Four hypertension-related variants were associated with congenital heart defects among NHW women (N = 1,568 with affected pregnancies). For example, 1 intronic variant in ARHGAP2, rs633185, was associated with conotruncal defects (odds ratio [OR]: 1.3, 95% confidence interval [CI]: 1.1-1.6). Additionally, 2 variants were associated with congenital heart defects among Hispanic women (N = 489 with affected pregnancies). The GRS had a significant association with septal defects (OR: 2.1, 95% CI: 1.2-3.5) among NHW women.

CONCLUSIONS

We replicated a previously reported association between rs633185 and conotruncal defects. Although additional hypertension-related SNPs were also associated with congenital heart defects, more work is needed to better understand the relationship between genetic risk for maternal hypertension and congenital heart defects occurrence.

Causes of neonatal and postneonatal death among infants with birth defects in Texas

BACKGROUND

The proportion of deaths attributed to various causes has not been quantified among infants with birth defects. We sought to describe the causes of neonatal and postneonatal death among infants in the Texas Birth Defects Registry.

METHODS

We calculated frequencies and percentages for both underlying causes and all causes (underlying or contributing) of neonatal (0-27 days) and postneonatal (28-364 days) death listed on death certificates among infants born alive with birth defects and delivered in Texas during 1999-2013 (n = 8,389 deaths). Analyses were repeated separately for infants with isolated, multiple, and syndromic defects.

RESULTS

After birth defects, the most frequently listed causes of neonatal death were preterm/low birth weight (10%), circulatory system diseases (8%), and sepsis (5%). The leading postneonatal causes of death beyond birth defects were circulatory system diseases (32%), sepsis (11%), and renal failure (7%).

CONCLUSIONS

Improved understanding of the causes of mortality among infants with birth defects may help identify priorities for postnatal care. Our results suggest that potentially modifiable causes of death (e.g., circulatory system diseases, sepsis) contribute substantially to mortality in this population. Prioritizing continued improvements in prevention, diagnosis, and management of preventable conditions may reduce mortality among infants born with birth defects.

Patterns of co-occurring birth defects among infants with hypospadias

INTRODUCTION

Hypospadias, one of the most common male genital birth defects, occurs in 1 out of every 200 male births in the United States and is increasing in prevalence globally.

OBJECTIVE

This study aimed to characterize the combinations of birth defects that co-occur with hypospadias more often than expected by chance, while accounting for the complex clustering patterns of congenital defects.

STUDY DESIGN

We analyzed cases with hypospadias and at least one additional co-occurring defect from the Texas Birth Defect Registry born between 1999 and 2014. For each combination, we calculated adjusted observed-to-expected (O/E) ratios, using Co-Occurring Defect Analysis (CODA).

RESULTS

Among 16,442 cases with hypospadias and without known syndromes, 2,084 (12.7%) had at least one additional defect. Many of the birth defect combinations within the highest adjusted O/E ratios included cardiac, musculoskeletal, and additional urogenital defects. For example, a top combination with an adjusted O/E of 139.0 included renal agenesis and dysgenesis, reduction defects of the upper limb, and other anomalies of upper limb (including shoulder girdle). High adjusted O/E ratios were also observed in combinations that included defects outside of the urogenital developmental field. For instance, the combination with the highest O/E ratio included buphthalmos, and congenital cataract and lens anomalies (adjusted O/E ratio: 192.9). Similar results were obtained when we restricted our analyses to cases with second- or third-degree hypospadias.

DISCUSSION

Many combinations in the top results were expected (e.g., multiple urogenital defects); however, some combinations with seemingly unrelated patterns of defects may suggest the presence of some etiologic mechanisms yet to be identified.

CONCLUSION

In summary, this study described patterns of co-occurring defect combinations with hypospadias that can inform further study and may provide insights for screening and diagnostic practices.

The risk of birth defects with conception by ART

STUDY QUESTION

What is the association between ART conception and treatment parameters and the risk of birth defects?

SUMMARY ANSWER

Compared to naturally conceived singleton infants, the risk of a major nonchromosomal defect among ART singletons conceived with autologous oocytes and fresh embryos without use of ICSI was increased by 18%, with increases of 42% and 30% for use of ICSI with and without male factor diagnosis, respectively.

WHAT IS KNOWN ALREADY

Prior studies have indicated that infertility and ART are associated with an increased risk of birth defects but have been limited by small sample size and inadequate statistical power, failure to differentiate results by plurality, differences in birth defect definitions and methods of ascertainment, lack of information on ART treatment parameters or study periods spanning decades resulting in a substantial historical bias as ART techniques have improved.

STUDY DESIGN, SIZE, DURATION

This was a population-based cohort study linking ART cycles reported to the Society for Assisted Reproductive Technology Clinic Outcome Reporting System (SART CORS) from 1 January 2004 to 31 December 2015 that resulted in live births from 1 September 2004 to 31 December 2016 in Massachusetts and North Carolina and from 1 September 2004 to 31 December 2015 for Texas and New York: these were large and ethnically diverse States, with birth defect registries utilizing the same case definitions and data collected, and with high numbers of ART births annually. A 10:1 sample of non-ART births were chosen within the same time period as the ART birth. Naturally conceived ART siblings were identified through the mother's information. Non-ART children were classified as being born to women who conceived with ovulation induction (OI)/IUI when there was an indication of infertility treatment on the birth certificate, but the woman did not link to the SART CORS; all others were classified as being naturally conceived.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population included 135 051 ART children (78 362 singletons and 56 689 twins), 23 647 naturally conceived ART siblings (22 301 singletons and 1346 twins) and 9396 children born to women treated with OI/IUI (6597 singletons and 2799 twins) and 1 067 922 naturally conceived children (1 037 757 singletons and 30 165 twins). All study children were linked to their respective State birth defect registries to identify major defects diagnosed within the first year of life. We classified children with major defects as either chromosomal (i.e. presence of a chromosomal defect with or without any other major defect) or nonchromosomal (i.e. presence of a major defect but having no chromosomal defect), or all major defects (chromosomal and nonchromosomal). Logistic regression models were used to generate adjusted odds ratios (AORs) and 95% CI to evaluate the risk of birth defects due to conception with ART (using autologous oocytes and fresh embryos), and with and without the use of ICSI in the absence or presence of male factor infertility, with naturally conceived children as the reference. Analyses within the ART group were stratified by combinations of oocyte source (autologous, donor) and embryo state (fresh, thawed), with births from autologous oocytes and fresh embryos as the reference. Analyses limited to fresh embryos were stratified by oocyte source (autologous, donor) and the use of ICSI. Triplets and higher-order multiples were excluded.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 21 998 singleton children (1.9%) and 3037 twin children (3.3%) had a major birth defect. Compared to naturally conceived children, ART singletons (conceived from autologous oocytes, fresh embryos without the use of ICSI) had increased risks of a major nonchromosomal birth defect (AOR 1.18, 95% 1.05, 1.32), cardiovascular defects (AOR 1.20, 95% CI 1.03, 1.40), and any birth defect (AOR 1.18, 95% CI 1.09, 1.27). Compared to naturally conceived children, ART singletons conceived (from autologous oocytes, fresh embryos) with the use of ICSI, the risks were increased for a major nonchromosomal birth defect (AOR 1.30, 95% CI 1.16, 1.45 without male factor diagnosis; AOR 1.42, 95% CI 1.28, 1.57 with male factor diagnosis); blastogenesis defects (AOR 1.49, 95% CI 1.08, 2.05 without male factor; AOR 1.56, 95% CI 1.17, 2.08 with male factor); cardiovascular defects (AOR 1.28, 95% CI 1.10,1.48 without male factor; AOR 1.45, 95% CI 1.27, 1.66 with male factor); in addition, the risk for musculoskeletal defects was increased (AOR 1.34, 95% CI 1.01, 1.78 without male factor) and the risk for genitourinary defects in male infants was increased (AOR 1.33, 95% CI 1.08, 1.65 with male factor). Comparisons within ART singleton births conceived from autologous oocytes and fresh embryos indicated that the use of ICSI was associated with increased risks of a major nonchromosomal birth defect (AOR 1.18, 95% CI 1.03, 1.35), blastogenesis defects (AOR 1.65, 95% CI 1.08, 2.51), gastrointestinal defects (AOR 2.21, 95% CI 1.28, 3.82) and any defect (AOR 1.11, 95% CI 1.01, 1.22). Compared to naturally conceived children, ART singleton siblings had increased risks of musculoskeletal defects (AOR 1.32, 95% CI 1.04, 1.67) and any defect (AOR 1.15, 95% CI 1.08, 1.23). ART twins (conceived with autologous oocytes, fresh embryos, without ICSI) were at increased risk of chromosomal defects (AOR 1.89, 95% CI 1.10, 3.24) and ART twin siblings were at increased risk of any defect (AOR 1.26, 95% CI 1.01, 1.57). The 18% increased risk of a major nonchromosomal birth defect in singleton infants conceived with ART without ICSI (∼36% of ART births), the 30% increased risk with ICSI without male factor (∼33% of ART births), and the 42% increased risk with ICSI and male factor (∼31% of ART births) translates into an estimated excess of 386 major birth defects among the 68 908 singleton children born by ART in 2017.

LIMITATIONS, REASONS FOR CAUTION

In the SART CORS database, it was not possible to differentiate method of embryo freezing (slow freezing vs vitrification), and data on ICSI was only available in the fresh embryo ART group. In the OI/IUI group, it was not possible to differentiate type of non-ART treatment utilized, and in both the ART and OI/IUI groups, data were unavailable on duration of infertility.

WIDER IMPLICATIONS OF THE FINDINGS

The use of ART is associated with increased risks of a major nonchromosomal birth defect, cardiovascular defect and any defect in singleton children, and chromosomal defects in twins; the use of ICSI further increases this risk, the most with male factor infertility. These findings support the judicious use of ICSI only when medically indicated. The relative contribution of ART treatment parameters versus the biology of the subfertile couple to this increased risk remains unclear and warrants further study.

STUDY FUNDING/COMPETING INTEREST(S)

This project was supported by grant R01 HD084377 from the National Institute of Child Health and Human Development. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institute of Child Health and Human Development, or the National Institutes of Health, nor any of the State Departments of Health which contributed data. E.W. is a contract vendor for SART; all other authors report no conflicts.

TRIAL REGISTRATION NUMBER

N/A.

A Comprehensive Assessment of Co-occurring Birth Defects among Infants with Non-Syndromic Anophthalmia or Microphthalmia

PURPOSE

Infants with anophthalmia or microphthalmia frequently have co-occurring birth defects. Nonetheless, there have been few investigations of birth defect patterns among these children. Such studies may identify novel multiple malformation syndromes, which could inform future research into the developmental processes that lead to anophthalmia/microphthalmia and assist physicians in determining whether further testing is appropriate.

METHODS

This study includes cases with anophthalmia/microphthalmia identified by the Texas Birth Defects Registry from 1999 to 2014 without clinical or chromosomal diagnoses of recognized syndromes. We calculated adjusted observed-to-expected ratios for two - through five-way birth defect combinations involving anophthalmia/microphthalmia to estimate whether these combinations co-occur more often than would be expected if they were independent. We report combinations observed in ≥5 cases.

RESULTS

We identified 653 eligible cases with anophthalmia/microphthalmia (514 [79%] with co-occurring birth defects), and 111 birth defect combinations, of which 44 were two-way combinations, 61 were three-way combinations, six were four-way combinations and none were five-way combinations. Combinations with the largest observed-to-expected ratios were those involving central nervous system (CNS) defects, head/neck defects, and orofacial clefts. We also observed multiple combinations involving cardiovascular and musculoskeletal defects.

CONCLUSION

Consistent with previous reports, we observed that a large proportion of children diagnosed with anophthalmia/microphthalmia have co-occurring birth defects. While some of these defects may be part of a sequence involving anophthalmia/microphthalmia (e.g., CNS defects), other combinations could point to as yet undescribed susceptibility patterns (e.g., musculoskeletal defects). Data from population-based birth defect registries may be useful for accelerating the discovery of previously uncharacterized malformation syndromes.

Prevalence and mortality in children with congenital diaphragmatic hernia: a multicountry study

PURPOSE

This study determined the prevalence, mortality, and time trends of children with congenital diaphragmatic hernia (CDH).

METHODS

Twenty-five hospital- and population-based surveillance programs in 19 International Clearinghouse for Birth Defects Surveillance and Research member countries provided birth defects mortality data between 1974 and 2015. CDH cases included live births, stillbirths, or elective termination of pregnancy for fetal anomalies. Prevalence, cumulative mortality rates, and 95% confidence intervals (CIs) were calculated using Poisson regression and a Kaplan-Meier product-limit method. Joinpoint regression analyses were conducted to assess time trends.

RESULTS

The prevalence of CDH was 2.6 per 10,000 total births (95% CI: 2.5-2.7), slightly increasing between 2001 and 2012 (average annual percent change = 0.5%; 95% CI:-0.6 to 1.6). The total percent mortality of CDH was 37.7%, with hospital-based registries having more deaths among live births than population-based registries (45.1% vs. 33.8%). Mortality rates decreased over time (average annual percent change = -2.4%; 95% CI: -3.8 to 1.1). Most deaths due to CDH occurred among 2- to 6-day-old infants for both registry types (36.3%, hospital-based; 12.1%, population-based).

CONCLUSIONS

The mortality of CDH has decreased over time. Mortality remains high during the first week and varied by registry type.

Male Sex and the Risk of Childhood Cancer: The Mediating Effect of Birth Defects

Background

There is a persistent, unexplained disparity in sex ratio among childhood cancer cases, whereby males are more likely to develop most cancers. This male predominance is also seen for most birth defects, which are strongly associated with risk of childhood cancer. We conducted mediation analysis to estimate whether the increased risk of cancer among males is partially explained by birth defect status.

Methods

We used a population-based birth cohort with linked data from birth certificates, birth defects registries, and cancer registries from Arkansas, Michigan, North Carolina, and Texas. We conducted counterfactual mediation analysis to estimate the natural direct and indirect effects of sex on cancer risk, modeling birth defect status as mediator. State; birth year; plurality; and maternal race and ethnicity, age, and education were considered confounders. We conducted separate analyses limited to cancers diagnosed younger than 1 year of age.

Results

Our dataset included 10 181 074 children: 15 110 diagnosed with cancer, 539 567 diagnosed with birth defects, and 2124 co-occurring cases. Birth defect status mediated 38% of the association between sex and cancer overall. The proportion mediated varied by cancer type, including acute myeloid leukemia (93%), neuroblastoma (35%), and non-Hodgkin lymphoma (6%). Among children younger than 1 year of age at cancer diagnosis, the proportion mediated was substantially higher (82%).

Conclusions

Our results suggest that birth defects mediate a statistically significant proportion of the relationship between sex and childhood cancer. The proportion mediated varied by cancer type and diagnosis age. These findings improve our understanding of the causal pathway underlying male sex as a risk factor for childhood cancer.

Risk factors and time trends for isolated craniosynostosis

BACKGROUND

We sought to investigate associations between maternal/infant characteristics and isolated craniosynostosis as well as its subtypes sagittal, metopic, and coronal synostosis, and assess trends in the prevalence of these conditions.

METHODS

We identified cases in the Texas Birth Defects Registry from 1999 to 2014. We used Poisson regression to identify associations between maternal/infant characteristics and craniosynostosis. We used joinpoint regression and unadjusted Poisson regression to evaluate temporal trends. Finally, we computed adjusted Poisson models to evaluate whether temporal trends were evident after accounting for changes in the population distributions of maternal/infant characteristics over time.

RESULTS

Relative to all live births in the general population, cases were more frequently male or preterm. Mothers of cases were more frequently non-Hispanic white and more frequently obese. Non-Hispanic black or Hispanic maternal race/ethnicity was associated with a lower prevalence of all craniosynostosis subtypes. Previous live births were associated with sagittal synostosis; residence on the U.S.-Mexico border was associated with sagittal and coronal synostosis. The prevalence of any isolated craniosynostosis increased (average annual percent change estimated from joinpoint regression [AAPC]: 2.9%), as did the prevalences of sagittal (AAPC: 3.3%) and metopic synostosis (AAPC: 5.4%). In crude Poisson models, the same temporal trends were observed, however these were attenuated after adjusting for maternal/infant characteristics.

CONCLUSIONS

Prevalence of isolated craniosynostosis increased from 1999 to 2014. The largest AAPC was observed for metopic synostosis. Changes in the population distribution of associated maternal/infant characteristics may explain these trends.

A multi-country study of prevalence and early childhood mortality among children with omphalocele

BACKGROUND

Omphalocele is the second most common abdominal birth defect and often occurs with other structural and genetic defects. The objective of this study was to determine omphalocele prevalence, time trends, and mortality during early childhood, by geographical region, and the presence of associated anomalies.

METHODS

We conducted a retrospective study with 23 birth defect surveillance systems in 18 countries who are members of the International Clearinghouse for Birth Defects Surveillance and Research that submitted data on cases ascertained from 2000 through 2012, approximately 16 million pregnancies were surveyed that resulted in live births, stillbirths, or elective terminations of pregnancy for fetal anomalies (ETOPFA) and cases with omphalocele were included. Overall prevalence and mortality rates for specific ages were calculated (day of birth, neonatal, infant, and early childhood). We used Kaplan-Meier estimates with 95% confidence intervals (CI) to calculate cumulative mortality and joinpoint regression for time trend analyses.

RESULTS

The prevalence of omphalocele was 2.6 per 10,000 births (95% CI: 2.5, 2.7) and showed no temporal change from 2000-2012 (average annual percent change = -0.19%, p = .52). The overall mortality rate was 32.1% (95% CI: 30.2, 34.0). Most deaths occurred during the neonatal period and among children with multiple anomalies or syndromic omphalocele. Prevalence and mortality varied by registry type (e.g., hospital- vs. population-based) and inclusion or exclusion of ETOPFA.

CONCLUSIONS

The prevalence of omphalocele showed no temporal change from 2000-2012. Approximately one-third of children with omphalocele did not survive early childhood with most deaths occurring in the neonatal period.

Assessment of Birth Defects and Cancer Risk in Children Conceived via In Vitro Fertilization in the US

IMPORTANCE

Children with birth defects have a greater risk of developing cancer, but this association has not yet been evaluated in children conceived with in vitro fertilization (IVF).

OBJECTIVE

To assess whether the association between birth defects and cancer is greater in children conceived via IVF compared with children conceived naturally.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of live births, birth defects, and cancer from Massachusetts, New York, North Carolina, and Texas included 1 000 639 children born to fertile women and 52 776 children conceived via IVF (using autologous oocytes and fresh embryos) during 2004-2016 in Massachusetts and North Carolina, 2004-2015 in New York, and 2004-2013 in Texas. Children were followed up for an average of 5.7 years (6 008 985 total person-years of exposure). Data analysis was conducted from April 1 to August 31, 2020.

EXPOSURES

Conception by IVF for state residents who gave birth to liveborn singletons during the study period. Birth defect diagnoses recorded by statewide registries.

MAIN OUTCOMES AND MEASURES

Cancer diagnosis as recorded by state cancer registries. Cox proportional hazards regression models were used to estimate hazard ratios (HRs) and 95% CIs for birth defect-cancer associations separately in fertile and IVF groups.

RESULTS

A total of 1 000 639 children (51.3% boys; 69.7% White; and 38.3% born between 2009-2012) were in the fertile group and 52 776 were in the IVF group (51.3% boys; 81.3% White; and 39.6% born between 2009-2012). Compared with children without birth defects, cancer risks were higher among children with a major birth defect in the fertile group (hazard ratio [HR], 3.15; 95% CI, 2.40-4.14) and IVF group (HR, 6.90; 95% CI, 3.73-12.74). The HR of cancer among children with a major nonchromosomal defect was 2.07 (95% CI, 1.47-2.91) among children in the fertile group and 4.04 (95% CI, 1.86-8.77) among children in the IVF group. The HR of cancer among children with a chromosomal defect was 15.45 (95% CI, 10.00-23.86) in the fertile group and 38.91 (95% CI, 15.56-97.33) in the IVF group.

CONCLUSIONS AND RELEVANCE

This study found that among children with birth defects, those conceived via IVF were at greater risk of developing cancer compared with children conceived naturally.

Birth defects that co-occur with non-syndromic gastroschisis and omphalocele

Gastroschisis and omphalocele are the two most common abdominal wall birth defects, and epidemiologic characteristics and frequency of occurrence as part of a syndromic condition suggest distinct etiologies between the two defects. We assessed complex patterns of defect co-occurrence with these defects separately using the Texas Birth Defects Registry. We used co-occurring defect analysis (CODA) to compute adjusted observed-to-expected (O/E) ratios for all observed birth defect patterns. There were 2,998 non-syndromic (i.e., no documented syndrome diagnosis identified) cases with gastroschisis and 789 (26%) of these had additional co-occurring defects. There were 720 non-syndromic cases with omphalocele, and 404 (56%) had additional co-occurring defects. Among the top 30 adjusted O/E ratios for gastroschisis, most of the co-occurring defects were related to the gastrointestinal system, though cardiovascular and kidney anomalies were also present. Several of the top 30 combinations co-occurring with omphalocele appeared suggestive of OEIS (omphalocele, exstrophy of cloaca, imperforate anus, spinal defects) complex. After the exclusion of additional cases with features suggestive of OEIS in a post-hoc sensitivity analysis, the top combinations involving defects associated with OEIS (e.g., spina bifida) were no longer present. The remaining top combinations involving omphalocele included cardiovascular, gastrointestinal, and urogenital defects. In summary, we identified complex patterns of defects that co-occurred more frequently than expected with gastroschisis and omphalocele using a novel software platform. Better understanding differences in the patterns between gastroschisis and omphalocele could lead to additional etiologic insights.

The association between newborn screening analytes as measured on a second screen and childhood autism in a Texas Medicaid population

Autism (or autism spectrum disorder [ASD]) is an often disabling childhood neurologic condition of mostly unknown cause. We previously explored whether there was an association of ASD with any analyte measured in the first newborn screening blood test. Here we explore the second screen. Our matched case-control study examined data on 3-5 year-old patients with any ASD diagnosis in the Texas Medicaid system in 2010-2012. Subjects were linked to their 2007-2009 newborn screening blood test data, which included values for 36 analytes or analyte ratios. Data were available for 3,005 cases and 6,212 controls. The most compelling associations were evident for fatty acid oxidation analytes octanoylcarnitine (C8) and octanoylcarnitine/acetylcarnitine (C8/C2). Their adjusted odds ratios comparing 10th versus first analyte deciles were between 1.42 and 1.54 in total births, term births, and males. C8 was consistent with first screen results. Adipylcarnitine (C6DC), an organic acid analyte, showed opposite results in the two screens. Several other analytes exhibiting significant associations in the first screen did not in the second. Our results provide evidence that abnormal newborn blood levels of some carnitines may be associated with risk of later ASD, possibly related to their involvement with mitochondrial function in the developing brain.

Cancer diagnostic profile in children with structural birth defects: An assessment in 15,000 childhood cancer cases

BACKGROUND

Birth defects are established risk factors for childhood cancer. Nonetheless, cancer epidemiology in children with birth defects is not well characterized.

METHODS

Using data from population-based registries in 4 US states, this study compared children with cancer but no birth defects (n = 13,111) with children with cancer and 1 or more nonsyndromic birth defects (n = 1616). The objective was to evaluate cancer diagnostic characteristics, including tumor type, age at diagnosis, and stage at diagnosis.

RESULTS

Compared with the general population of children with cancer, children with birth defects were diagnosed with more embryonal tumors (26.6% vs 18.7%; q < 0.001), including neuroblastoma (12.5% vs 8.2%; q < 0.001) and hepatoblastoma (5.0% vs 1.3%; q < 0.001), but fewer hematologic malignancies, including acute lymphoblastic leukemia (12.4% vs 24.4%; q < 0.001). In age-stratified analyses, differences in tumor type were evident among children younger than 1 year and children 1 to 4 years old, but they were attenuated among children 5 years of age or older. The age at diagnosis was younger in children with birth defects for most cancers, including leukemia, lymphoma, astrocytoma, medulloblastoma, ependymoma, embryonal tumors, and germ cell tumors (all q < 0.05).

CONCLUSIONS

The results indicate possible etiologic heterogeneity in children with birth defects, have implications for future surveillance efforts, and raise the possibility of differential cancer ascertainment in children with birth defects.

LAY SUMMARY

Scientific studies suggest that children with birth defects are at increased risk for cancer. However, these studies have not been able to determine whether important tumor characteristics, such as the type of tumor diagnosed, the age at which the tumor is diagnosed, and the degree to which the tumor has spread at the time of diagnosis, are different for children with birth defects and children without birth defects. This study attempts to answer these important questions. By doing so, it may help scientists and physicians to understand the causes of cancer in children with birth defects and diagnose cancer at earlier stages when it is more treatable.

Third grade academic achievement among children conceived with the use of in vitro fertilization: a population-based study in Texas

OBJECTIVE

To evaluate if there are differences in standardized testing results at the end of third grade between children conceived with the use of in vitro fertilization (IVF) and those conceived spontaneously.

DESIGN

Retrospective population-based cohort.

SETTING

Texas public school system.

PATIENT(S)

Singleton and twin children 8-9 years of age who took the third-grade public school standardized testing in Texas from 2012 to 2018.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Standardized testing in reading and mathematics.

RESULT(S)

After exclusions, there were 6,970 IVF and 12,690 non-IVF children with reading scores and 6,973 IVF and 12,729 non-IVF children with mathematics scores. IVF children scored significantly higher in reading (singletons: 1,543 ± 2 vs. 1,525 ± 1; twins: 1,534 ± 2 vs. 1,504 ± 5 [mean ± SE]), and mathematics (singletons: 1,566 ± 2 vs. 1,550 ± 1; twins: 1,557 ± 2 vs. 1,529 ± 5). Children of mothers ≥30 years of age scored consistently higher than children of mothers 18-29 years of age. The differences were of similar magnitude between IVF and control children for older ages, but not significant for IVF. Within the IVF group, there were no significant differences between children born from fresh versus froze-thawed embryos.

CONCLUSION(S)

Children of ages 8-9 years who were conceived with the use of IVF performed as well on third-grade reading and math assessments as their counterparts who were conceived spontaneously. We also found consistent racial and ethnic differences, gender differences, and beneficial effects of older maternal age. Because we were not able to adjust adequately for socioeconomic status and other confounding factors, which may explain some of the observed differences, we conclude that there is no negative effect of IVF conception on academic achievement in third grade.

Acculturation and selected birth defects among non-Hispanic Blacks in a population-based case-control study

BACKGROUND

There are noted birth defects prevalence differences between race/ethnicity groups. For instance, non-Hispanic (NH) Black mothers are more likely to have an infant with encephalocele, although less likely to have an infant with anotia/microtia compared to NH Whites. When stratifying by nativity and years lived within the United States, additional variations become apparent.

METHODS

Data from the National Birth Defects Prevention Study were used to calculate descriptive statistics and estimate crude/adjusted odds ratios (aORs) and 95% confidence intervals (95%CIs) among NH Blacks with one of 30 major defects and non-malformed controls. Total case/controls were as follows: U.S.- (2,773/1101); Foreign- (343/151); African-born (161/64). Study participants were also examined by number of years lived in the U.S. (≤5 vs. 6+ years).

RESULTS

Compared to U.S.-born, foreign-born NH Black controls tended to be older, had more years of education, and were more likely to have a higher household income. They also had fewer previous livebirths and were less likely to be obese. In the adjusted analyses, two defect groups were significantly attenuated: limb deficiencies, aORs/95%CIs = (0.44 [0.20-0.97]) and septal defects (0.69 [0.48-0.99]). After stratifying by years lived in the United States, the risk for hydrocephaly (2.43 [1.03-5.74]) became apparent among those having lived 6+ years in the United States. When restricting to African-born mothers, none of the findings were statistically significant.

CONCLUSIONS

Foreign-born NH Blacks were at a reduced risk for a few selected defects. Results were consistent after restricting to African-born mothers and did not change considerably when stratifying by years lived in the United States.