Antifungal medication use during early pregnancy and the risk of congenital heart defects in the National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Fungal infections are common among pregnant people. Recent studies suggest positive associations between oral antifungals used to treat fungal infections and congenital heart defects (CHDs).

METHODS

We estimated associations between first trimester antifungal use and 20 major, specific CHDs using data from the National Birth Defects Prevention Study (NBDPS), a multi-site, case-control study that included pregnancies with estimated delivery dates from October 1997 through December 2011. Infants with CHDs ("cases") were ascertained from 10 birth defect surveillance programs. Live born infants without major birth defects ("controls") were randomly selected from birth records or hospital discharge lists. First trimester antifungal use was self-reported via maternal interview. We estimated adjusted odds ratios (AORs) and 95% confidence intervals (CIs) using logistic regression with Firth's penalized likelihood.

RESULTS

First trimester antifungal use was reported by 148/11,653 (1.3%) case and 123/11,427 (1.1%) control participants. We estimated AORs for 12 CHDs; six had AORs >1.5 (tetralogy of Fallot, double outlet right ventricle with transposition of the great arteries [DORV-TGA], atrioventricular septal defect, hypoplastic left heart syndrome, pulmonary atresia, muscular ventricular septal defect), and one (pulmonary valve stenosis) had an AOR <0.7. All CIs included the null, except for DORV-TGA.

CONCLUSIONS

First trimester antifungal use was rare. We observed some positive associations for several specific CHDs in our analysis, although the CIs largely included the null. Results do not support a large increase in risk, but smaller increases in risk for certain CHD cannot be ruled out.

Maternal exposure to zolpidem and risk of specific birth defects

Zolpidem is a non-benzodiazepine agent indicated for treatment of insomnia. While zolpidem crosses the placenta, little is known about its safety in pregnancy. We assessed associations between self-reported zolpidem use 1 month before pregnancy through to the end of the third month ("early pregnancy") and specific birth defects using data from two multi-site case-control studies: National Birth Defects Prevention Study and Slone Epidemiology Center Birth Defects Study. Analysis included 39,711 birth defect cases and 23,035 controls without a birth defect. For defects with ≥ 5 exposed cases, we used logistic regression with Firth's penalised likelihood to estimate adjusted odds ratios and 95% confidence intervals, considering age at delivery, race/ethnicity, education, body mass index, parity, early-pregnancy antipsychotic, anxiolytic, antidepressant use, early-pregnancy opioid use, early-pregnancy smoking, and study as potential covariates. For defects with three-four exposed cases, we estimated crude odds ratios and 95% confidence intervals. Additionally, we explored differences in odds ratios using propensity score-adjustment and conducted a probabilistic bias analysis of exposure misclassification. Overall, 84 (0.2%) cases and 46 (0.2%) controls reported early-pregnancy zolpidem use. Seven defects had sufficient sample size to calculate adjusted odds ratios, which ranged from 0.76 for cleft lip to 2.18 for gastroschisis. Four defects had odds ratios > 1.8. All confidence intervals included the null. Zolpidem use was rare. We could not calculate adjusted odds ratios for most defects and estimates are imprecise. Results do not support a large increase in risk, but smaller increases in risk for certain defects cannot be ruled out.

Antifungal medication use during pregnancy and the risk of selected major birth defects in the National Birth Defects Prevention Study, 1997-2011

PURPOSE

Recent studies suggest increased birth defect risk associated with maternal use of specific oral antifungals. We estimated associations between first-trimester antifungal use and selected non-cardiac birth defects using National Birth Defects Prevention Study (NBDPS) data.

METHODS

Participants with a pregnancy affected by a study-eligible birth defect ("cases") were ascertained from 10 birth defect surveillance programs; participants who delivered livebirths without a major birth defect ("controls") were randomly selected from birth records or hospital discharge lists. First-trimester antifungal use was self-reported via maternal interview. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for birth defects with ≥5 exposed cases using logistic regression. We estimated crude ORs and exact 95% CIs for birth defects with 3-4 exposed cases. Additionally, we conducted a probabilistic bias analysis of exposure misclassification.

RESULTS

Our analysis included 19 624 cases and 11 427 controls; 257 (1.3%) cases and 123 (1.1%) controls reported first-trimester antifungal use. Of those who reported antifungals, 62.6% of cases and 64.2% of controls reported topical antifungals; 10.1% of cases and 4.9% of controls reported oral antifungals. We observed the strongest associations for encephalocele and Dandy-Walker malformation and modestly elevated estimates for several other defects. Bias-adjusted estimates were similar to the main analysis.

CONCLUSION

First-trimester antifungal use was positively associated with several birth defects in our analysis, although CIs were imprecise. Further study is warranted to investigate associations between antifungal use and birth defects, including potential bias due to confounding by indication.

Maternal exposure to heparin products and risk of birth defects in the National Birth Defects Prevention Study

BACKGROUND

Heparin and low-molecular-weight heparin are the preferred anticoagulants during pregnancy as they do not cross the placenta. Although research on the safety of heparin products has been reassuring, previous studies have considered birth defects as a single outcome or by larger organ system and have not examined associations with specific birth defects.

METHODS

We analyzed data from the National Birth Defects Prevention Study, a multisite, population-based case-control study from 1997 to 2011. We used unconditional logistic regression with Firth's penalized likelihood to calculate adjusted odds ratios (ORs) and profile likelihood 95% confidence intervals (CIs) for defects with at least five exposed cases. For defects with 3-4 exposed cases, we estimated crude ORs and exact 95% CIs.

RESULTS

Of the 42,743 women in our analysis, 117 (0.4%) case and 44 (0.4%) control mothers reported using a heparin product in early pregnancy. The adjusted ORs ranged from 0.9 to 3.9 and were elevated for anorectal atresia (OR = 2.0, 95% CI = 0.8-4.3), longitudinal limb deficiency (3.5, 1.3-7.8), transverse limb deficiency (1.8, 0.6-4.3), atrioventricular septal defect (3.9, 1.4-9.0), and secundum atrial septal defect (2.2, 1.2-3.8).

CONCLUSIONS

We observed elevated associations for some birth defects, although heparin is a rare exposure, which limited our ability to evaluate many associations. Future studies that can explore specific birth defects and adequately control for confounding by indication are needed. Given that women with an indication for heparin products during pregnancy often need to take medication, one must remain mindful of the underlying risk of a birth defect that exists regardless of medication use.

Risk of birth defects by pregestational type 1 or type 2 diabetes: National Birth Defects Prevention Study, 1997-2011

BACKGROUND

Previous studies found consistent associations between pregestational diabetes and birth defects. Given the different biological mechanisms for type 1 (PGD1) and type 2 (PGD2) diabetes, we used National Birth Defects Prevention Study (NBDPS) data to estimate associations by diabetes type.

METHODS

The NBDPS was a study of major birth defects that included pregnancies with estimated delivery dates from October 1997 to December 2011. We compared self-reported PGD1 and PGD2 for 29,024 birth defect cases and 10,898 live-born controls. For case groups with ≥5 exposed cases, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs) for the association between specific defects and each diabetes type. We calculated crude ORs (cORs) and 95% CIs with Firth's penalized likelihood for case groups with 3-4 exposed cases.

RESULTS

Overall, 252 (0.9%) cases and 24 (0.2%) control mothers reported PGD1, and 357 (1.2%) cases and 34 (0.3%) control mothers reported PGD2. PGD1 was associated with 22/26 defects examined and PGD2 was associated with 29/39 defects examined. Adjusted ORs ranged from 1.6 to 70.4 for PGD1 and from 1.6 to 59.9 for PGD2. We observed the strongest aORs for sacral agenesis (PGD1: 70.4, 32.3-147; PGD2: 59.9, 25.4-135). For both PGD1 and PGD2, we observed elevated aORs in every body system we evaluated, including central nervous system, orofacial, eye, genitourinary, gastrointestinal, musculoskeletal, and cardiac defects.

CONCLUSIONS

We observed positive associations between both PGD1 and PGD2 and birth defects across multiple body systems. Future studies should focus on the role of glycemic control in birth defect risk to inform prevention efforts.

Health Care Usage Among Adolescents With Congenital Heart Defects at 5 Sites in the United States, 2011 to 2013

Background

We sought to characterize health care usage for adolescents with congenital heart defects (CHDs) using population‐based multisite surveillance data.

Methods and Results

Adolescents aged 11 to 18 years with ≥1 CHD‐related diagnosis code and residing in 5 US sites were identified in clinical and administrative data sources for the years 2011 to 2013. Sites linked data on all inpatient, emergency department (ED), and outpatient visits. Multivariable log‐binomial regression models including age, sex, unweighted Charlson comorbidity index, CHD severity, cardiology visits, and insurance status, were used to identify associations with inpatient, ED, and outpatient visits. Of 9626 eligible adolescents, 26.4% (n=2543) had severe CHDs and 21.4% had Charlson comorbidity index >0. At least 1 inpatient, ED, or outpatient visit was reported for 21%, 25%, and 96% of cases, respectively. Cardiology visits, cardiac imaging, cardiac procedures, and vascular procedures were reported for 38%, 73%, 10%, and 5% of cases, respectively. Inpatient, ED, and outpatient visits were consistently higher for adolescents with severe CHDs compared with nonsevere CHDs. Adolescents with severe and nonsevere CHDs had higher health care usage compared with the 2011 to 2013 general adolescent US population. Adolescents with severe CHDs versus nonsevere CHDs were twice as likely to have at least 1 inpatient visit when Charlson comorbidity index was low (Charlson comorbidity index =0). Adolescents with CHDs and public insurance, compared with private insurance, were more likely to have inpatient (adjusted prevalence ratio, 1.5 [95% CI, 1.3–1.7]) and ED (adjusted prevalence ratio, 1.6 [95% CI, 1.4–1.7]) visits.

Conclusions

High resource usage by adolescents with CHDs indicates a substantial burden of disease, especially with public insurance, severe CHDs, and more comorbidities.

Interpregnancy interval and prevalence of selected birth defects: A multistate study

BACKGROUND

Both short and long interpregnancy intervals (IPIs) have been associated with adverse birth outcomes. We undertook a multistate study to describe the prevalence of selected birth defects by IPI.

METHODS

We obtained data from nine population-based state birth defects registries for singleton live births in 2000-2009 among mothers with a previous live birth identified through birth certificates. IPI was calculated as the difference between prior birthdate and start of the current pregnancy (conception date). We estimated prevalence of selected defects per 10,000 live births and prevalence ratios (PRs) with 95% confidence intervals (CIs) overall and stratified by maternal age at previous birth and race/ethnicity. Primary analyses focused on short IPI < 6 months and long IPI ≥ 60 months compared to 18-23 months (referent). Sensitivity analyses limited to active-surveillance states and those with<10% missing IPI.

RESULTS

Among 5,147,962 eligible births, 6.3% had short IPI while 19.8% had long IPI. Compared to referent, prevalence with short IPI was elevated for gastroschisis (3.7, CI: 3.0-4.5 vs. 2.0, CI: 1.6-2.4) and with both short and long IPI for tetralogy of Fallot (short: 3.4, 2.8-4.2 long: 3.8, 3.4-4.3 vs. 2.7, 2.3-3.2) and cleft lip ± palate (short: 9.9, 8.8-11.2 long: 9.2, 8.5-9.8 vs. 8.4, 7.6-9.2). Stratified analyses identified additional associations, including elevated prevalence of anencephaly with short IPI in younger mothers and limb defects with long IPI in those ages 25-34 at prior birth. Sensitivity analyses showed similar results.

CONCLUSION

In this population-based study, we observed increased prevalence of several birth defects with short and long IPI.

Maternal exposure to hydroxychloroquine and birth defects

Background

Hydroxychloroquine is a treatment for rheumatic disease and considered safe during pregnancy. Interest in hydroxychloroquine has increased as it is being examined as a potential treatment and prophylaxis for coronavirus disease 2019. Data on the risks of specific birth defects associated with hydroxychloroquine use are sparse.

Methods

Using data from two case–control studies (National Birth Defects Prevention Study and Slone Epidemiology Center Birth Defects Study), we described women who reported hydroxychloroquine use in pregnancy and the presence of specific major birth defects in their offspring. Cases had at least one major birth defect and controls were live‐born healthy infants. Women self‐reported medication use information in the few months before pregnancy through delivery.

Results

In total, 0.06% (19/31,468) of case and 0.04% (5/11,614) of control mothers in National Birth Defects Prevention Study, and 0.04% (11/29,838) of case and 0.05% (7/12,868) of control mothers in Birth Defects Study reported hydroxychloroquine use. Hydroxychloroquine users had complicated medical histories and frequent medication use for a variety of conditions. The observed birth defects among women taking hydroxychloroquine were varied and included nine oral cleft cases; the elevated observed:expected ratios for specific oral cleft phenotypes and for oral clefts overall had 95% confidence intervals that included 1.0.

Conclusion

While teratogens typically produce a specific pattern of birth defects, the observed birth defects among the hydroxychloroquine‐exposed women did not present a clear pattern, suggesting no meaningful evidence for the risk of specific birth defects. The number of exposed cases is small; results should be interpreted cautiously.

Access to cardiac surgery centers for cardiac and non-cardiac hospitalizations in adolescents and adults with congenital heart defects- a descriptive case series study

Background

Individuals with congenital heart defects (CHDs) are recommended to receive all inpatient cardiac and noncardiac care at facilities that can offer specialized care. We describe geographic accessibility to such centers in New York State and determine several factors associated with receiving care there.

Methods

We used inpatient hospitalization data from the Statewide Planning and Research Cooperative System (SPARCS) in New York State 2008–2013. In the absence of specific adult CHD care center designations during our study period, we identified pediatric/adult and adult-only cardiac surgery centers through the Cardiac Surgery Reporting System to estimate age-based specialized care. We calculated one-way drive and public transit time (in minutes) from residential address to centers using R gmapsdistance package and the Google Maps Distance Application Programming Interface (API). We calculated prevalence ratios using modified Poisson regression with model-based standard errors, fit with generalized estimating equations clustered at the hospital level and subclustered at the individual level.

Results

Individuals with CHDs were more likely to seek care at pediatric/adult or adult-only cardiac surgery centers if they had severe CHDs, private health insurance, higher severity of illness at encounter, a surgical procedure, cardiac encounter, and shorter drive time. These findings can be used to increase care receipt (especially for noncardiac care) at pediatric/adult or adult-only cardiac surgery centers, identify areas with limited access, and reduce disparities in access to specialized care among this high-risk population.

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.

Inpatient admissions and costs for adolescents and young adults with congenital heart defects in New York, 2009-2013

OBJECTIVES

Most individuals born with congenital heart defects (CHDs) survive to adulthood, but healthcare utilization patterns for adolescents and adults with CHDs have not been well described. We sought to characterize the healthcare utilization patterns and associated costs for adolescents and young adults with CHDs.

METHODS

We examined 2009-2013 New York State inpatient admissions of individuals ages 11-30 years with ≥1 CHD diagnosis codes recorded during any admission. We conducted multivariate linear regression using generalized estimating equations to examine associations between inpatient costs and sociodemographic and clinical variables.

RESULTS

We identified 5,100 unique individuals with 9,593 corresponding hospitalizations over the study period. Median inpatient cost and length of stay (LOS) were $10,720 and 3.0 days per admission, respectively; 55.1% were emergency admissions. Admission volume increased 48.7% from 2009 (1,538 admissions) to 2013 (2,287 admissions), while total inpatient costs increased 91.8% from 2009 ($27.2 million) to 2013 ($52.2 million). Inpatient admissions and costs rose more sharply over the study period for those with nonsevere CHDs compared to severe CHDs. Characteristics associated with higher costs were longer LOS, severe CHD, cardiac/vascular hospitalization classification, surgical procedures, greater severity of illness, and admission in New York City.

CONCLUSION

This study provides an informative baseline of health care utilization patterns and associated costs among adolescents and young adults with CHDs in New York State. Structured transition programs may aid in keeping this population in appropriate cardiac care as they move to adulthood.

Maternal Comorbidities and Complications of Delivery in Pregnant Women With Congenital Heart Disease

BACKGROUND

Pregnant women with congenital heart defects (CHDs) may be at increased risk for adverse events during delivery.

OBJECTIVES

This study sought to compare comorbidities and adverse cardiovascular, obstetric, and fetal events during delivery between pregnant women with and without CHDs in the United States.

METHODS

Comorbidities and adverse delivery events in women with and without CHDs were compared in 22,881,691 deliveries identified in the 2008 to 2013 National Inpatient Sample using multivariable logistic regression. Among those with CHDs, associations by CHD severity and presence of pulmonary hypertension (PH) were examined.

RESULTS

There were 17,729 deliveries to women with CHDs (77.5 of 100,000 deliveries). These women had longer lengths of stay and higher total charges than women without CHDs. They had greater odds of comorbidities, including PH (adjusted odds ratio [aOR]: 193.8; 95% confidence interval [CI]: 157.7 to 238.0), congestive heart failure (aOR: 49.1; 95% CI: 37.4 to 64.3), and coronary artery disease (aOR: 31.7; 95% CI: 21.4 to 47.0). Greater odds of adverse events were observed, including heart failure (aOR: 22.6; 95% CI: 20.5 to 37.3), arrhythmias (aOR: 12.4; 95% CI: 11.0 to 14.0), thromboembolic events (aOR: 2.4; 95% CI: 2.0 to 2.9), pre-eclampsia (aOR: 1.5; 95% CI: 1.3 to 1.7), and placenta previa (aOR: 1.5; 95% CI: 1.2 to 1.8). Cesarean section, induction, and operative vaginal delivery were more common, whereas fetal distress was less common. Among adverse events in women with CHDs, PH was associated with heart failure, hypertension in pregnancy, pre-eclampsia, and pre-term delivery; there were no differences in most adverse events by CHD severity.

CONCLUSIONS

Pregnant women with CHDs were more likely to have comorbidities and experience adverse events during delivery. These women require additional monitoring and care.

Maternal surgery and anesthesia during pregnancy and risk of birth defects in the National Birth Defects Prevention Study, 1997-2011

BACKGROUND

There is little recent research on the teratogenicity of maternal anesthesia exposure. We used National Birth Defects Prevention Study data to describe surgical procedures conducted during pregnancy and to estimate the risk of birth defects associated with periconceptional anesthesia exposure.

METHODS

We used logistic regression to assess associations between general and local anesthesia for surgery during the periconceptional period and specific birth defects. We calculated odds ratios and 95% confidence intervals for 25 birth defects with at least five exposed cases (11,501 controls, 24,337 cases), adjusted for maternal race/ethnicity, age, body mass index, periconceptional exposure to X-ray, CT, or radionuclide scans, and study site.

RESULTS

The most commonly reported procedures were dental, dermatologic, and cervical cerclage procedures, regardless of gestational timing. Overall, 226 case and 73 control women reported periconceptional general anesthesia; 230 case and 89 control women reported periconceptional local anesthesia. Women who reported general or local anesthesia were disproportionately non-Hispanic white and were more likely to report periconceptional opioid use and at least one periconceptional X-ray/CT/radionuclide scan. Women who reported general anesthesia were also more likely to report periconceptional injury. We did not observe any significant associations between either type of anesthesia exposure and the birth defects studied. Odds ratios were generally close to null and imprecise.

CONCLUSIONS

Our study population reported a wide range of surgical procedures during pregnancy, requiring both general and local anesthesia. Our findings suggest that periconceptional anesthesia is not strongly associated with the birth defects assessed in this study.

Surveillance of Congenital Heart Defects among Adolescents at Three U.S. Sites

The prevalence, co-morbidities, and healthcare utilization in adolescents with congenital heart defects (CHDs) is not well understood. Adolescents (11 to 19 years old) with a healthcare encounter between January 1, 2008 (January 1, 2009 for MA) and December 31, 2010 with a CHD diagnosis code were identified from multiple administrative data sources compiled at 3 US sites: Emory University, Atlanta, Georgia (EU); Massachusetts Department of Public Health (MA); and New York State Department of Health (NY). The estimated prevalence for any CHD was 4.77 (EU), 17.29 (MA), and 4.22 (NY) and for severe CHDs was 1.34 (EU), 3.04 (MA), and 0.88 (NY) per 1,000 adolescents. Private or commercial insurance was the most common insurance type for EU and NY, and Medicaid for MA. Inpatient encounters were more frequent in severe CHDs. Cardiac co-morbidities included rhythm and conduction disorders at 20% (EU), 46% (MA), and 9% (NY) as well as heart failure at 3% (EU), 15% (MA), and 2% (NY). Leading noncardiac co-morbidities were respiratory/pulmonary (22% EU, 34% MA, 16% NY), infectious disease (17% EU, 22% MA, 20% NY), non-CHD birth defects (12% EU, 23% MA, 14% NY), gastrointestinal (10% EU, 28% MA, 13% NY), musculoskeletal (10% EU, 32% MA, 11% NY), and mental health (9% EU, 30% MA, 11% NY). In conclusion, this study used a novel approach of uniform CHD definition and variable selection across administrative data sources in 3 sites for the first population-based CHD surveillance of adolescents in the United States. High resource utilization and co-morbidities illustrate ongoing significant burden of disease in this vulnerable population.

Maternal Hypertension, Antihypertensive Medication Use, and Small for Gestational Age Births in the National Birth Defects Prevention Study, 1997-2011

Background Small for gestational age (SGA) birth is associated with poor long-term health outcomes. It is unclear whether maternal antihypertensive medication increases risk of SGA independently of maternal hypertension. Methods We analyzed associations between maternal hypertension and antihypertensive medication use and SGA among non-malformed singleton controls in the National Birth Defects Prevention Study. We defined SGA as birthweight < 10th percentile for a given gestational age, sex, race/ethnicity, and parity. We included 1045 SGA and 10,019 non-SGA births. We used logistic regression to calculate adjusted odds ratios (AORs) and 95% confidence intervals (CIs). We assessed interaction between hypertension, antihypertensive use, and maternal race/ethnicity and age. Results Overall, 122 (11.7%) SGA and 892 (8.9%) non-SGA mothers reported hypertension and 21 (2.0%) SGA and 154 (1.5%) non-SGA mothers reported antihypertensive use. The most commonly reported medications were centrally-acting antiadrenergics, β-blockers, calcium channel blockers, and diuretics. Compared to normotensive pregnancies, maternal hypertension, regardless of treatment (AOR, 1.49 [95% CI, 1.20, 1.86]), and untreated maternal hypertension [AOR, 1.46 (95% CI, 1.15, 1.86)] were associated with SGA. We observed a positive, but not significant, association between antihypertensive use and SGA. SGA risk varied by maternal race/ethnicity, being highest among Hispanic mothers, and age, being highest among mothers ≥ 35 years, but statistical tests for interaction were not significant. Conclusions Consistent with the literature, our findings suggest that maternal hypertension slightly increases SGA risk. We did not observe an appreciably increased SGA risk associated with antihypertensive medication use beyond that of the underlying maternal hypertension.

Maternal antihypertensive medication use and selected birth defects in the National Birth Defects Prevention Study

BACKGROUND

There are limited data on the relationship between antihypertensive medication use in early pregnancy and risk of birth defects.

METHODS

Using data from the National Birth Defects Prevention Study, we examined associations between specific antihypertensive medication classes and 28 noncardiac birth defects. We analyzed self-reported data on 17,038 case and 11,477 control pregnancies with estimated delivery dates during 1997-2011. We used multivariable logistic regression to estimate odds ratios (ORs) and 95% confidence intervals, adjusted for maternal age, race/ethnicity, body mass index, parity, pregestational diabetes, and study site, for associations between individual birth defects and antihypertensive medication use during the first trimester of pregnancy. We compared risk among women reporting early pregnancy antihypertensive medication use to normotensive women.

RESULTS

Hypertensive women who reported early pregnancy antihypertensive medication use were more likely to be at least 35 years old, non-Hispanic Black, obese, multiparous, and to report pregestational diabetes than normotensive women. Compared to normotensive women, early pregnancy antihypertensive medication use was associated with increased risk of small intestinal atresia (adjusted OR 2.4, 95% CI 1.2-4.7) and anencephaly (adjusted OR 1.9, 95% CI 1.0-3.5). Risk of these defects was not specific to any particular medication class.

CONCLUSIONS

Maternal antihypertensive medication use was not associated with the majority of birth defects we analyzed, but was associated with an increased risk for some birth defects. Because we cannot entirely rule out confounding by the underlying hypertension and most ORs were based on small numbers, the increased risks observed should be interpreted with caution.

Women's periconceptional diet and risk of biliary atresia in offspring

INTRODUCTION

We examined the association of biliary atresia with maternal dietary intake, using National Birth Defects Prevention Study (NBDPS) data from 152 cases and 11,112 nonmalformed controls born 1997-2011.

METHODS

NBDPS is a multisite, population-based case-control study. Exposure data were from maternal telephone interviews, which included a food frequency questionnaire. Odds ratios (OR) and 95% confidence intervals (CI) were generated from logistic regression models that included nutritional factors as continuous variables and were adjusted for energy intake only or energy intake plus covariates (maternal race-ethnicity, education, age, prepregnancy body mass index, vitamin/mineral supplement intake, conception during summer). Models included a quadratic term for the nutrient if p < 0.10. ORs reflect odds of having biliary atresia for nutrient values at the 75th compared to 25th percentile values of each nutrient, based on distributions among controls.

RESULTS

ORs for which the 95% CI excluded 1.00 were energy-adjusted ORs for calcium (0.63), protein (0.65), riboflavin (0.71), and diet quality index (0.69), and fully adjusted ORs for calcium (0.68) and vitamin E (0.72). ORs that were fully adjusted for covariates tended to be closer to 1.0 than ORs adjusted only for energy intake. ORs for the other studied nutrients had 95% CIs that included 1.00.

CONCLUSIONS

NBDPS is the first study to include detailed information on maternal dietary intake and risk of biliary atresia. Our results suggest reduced risks associated with some nutrients, which may provide etiologic clues but should be interpreted with caution given the small number of cases and novelty of the investigation.

Proximity to Pediatric Cardiac Surgical Care among Adolescents with Congenital Heart Defects in 11 New York Counties

BACKGROUND

Many individuals with congenital heart defects (CHDs) discontinue cardiac care in adolescence, putting them at risk of adverse health outcomes. Because geographic barriers may contribute to cessation of care, we sought to characterize geographic access to comprehensive cardiac care among adolescents with CHDs.

METHODS

Using a population-based, 11-county surveillance system of CHDs in New York, we characterized proximity to the nearest pediatric cardiac surgical care center among adolescents aged 11 to 19 years with CHDs. Residential addresses were extracted from surveillance records documenting 2008 to 2010 healthcare encounters. Addresses were geocoded using ArcGIS and the New York State Street and Address Maintenance Program, a statewide address point database. One-way drive and public transit time from residence to nearest center were calculated using R packages gmapsdistance and rgeos with the Google Maps Distance Matrix application programming interface. A marginal model was constructed to identify predictors associated with one-way travel time.

RESULTS

We identified 2522 adolescents with 3058 corresponding residential addresses and 12 pediatric cardiac surgical care centers. The median drive time from residence to nearest center was 18.3 min, and drive time was 30 min or less for 2475 (80.9%) addresses. Predicted drive time was longest for rural western addresses in high poverty census tracts (68.7 min). Public transit was available for most residences in urban areas but for few in rural areas.

CONCLUSION

We identified areas with geographic barriers to surgical care. Future research is needed to determine how these barriers influence continuity of care among adolescents with CHDs. Birth Defects Research 109:1494-1503, 2017.© 2017 Wiley Periodicals, Inc.

Paternal and joint parental occupational pesticide exposure and spina bifida in the National Birth Defects Prevention Study, 1997 to 2002

BACKGROUND

Because of persistent concerns over the association between pesticides and spina bifida, we examined the role of paternal and combined parental occupational pesticide exposures in spina bifida in offspring using data from a large population-based study of birth defects.

METHODS

Occupational information from fathers of 291 spina bifida cases and 2745 unaffected live born control infants with estimated dates of delivery from 1997 to 2002 were collected by means of maternal report. Two expert industrial hygienists estimated exposure intensity and frequency to insecticides, herbicides, and fungicides. Multivariable logistic regression models were used to estimate adjusted odds ratios (aOR) and 95% confidence intervals (CI) for exposure to any pesticide and to any class of pesticide (yes/no; and by median), and exposure to combinations of pesticides (yes/no) and risk of spina bifida. Adjusted odds ratios were also estimated by parent exposed to pesticides (neither, mother only, father only, both parents).

RESULTS

Joint parental occupational pesticide exposure was positively associated with spina bifida (aOR, 1.5; 95% CI, 0.9-2.4) when compared with infants with neither maternal nor paternal exposures; a similar association was not observed when only one parent was exposed. There was a suggested positive association between combined paternal insecticide and fungicide exposures and spina bifida (aOR, 1.5; 95% CI, 0.8-2.8), however, nearly all other aORs were close to unity.

CONCLUSION

Overall, there was little evidence paternal occupational pesticide exposure was associated with spina bifida. However, the small numbers make it difficult to precisely evaluate the role of pesticide classes, individually and in combination. Birth Defects Research (Part A) 106:963-971, 2016. © 2016 Wiley Periodicals, Inc.

Maternal autoimmune disease and birth defects in the National Birth Defects Prevention Study

BACKGROUND

Little is known about the association between maternal autoimmune disease or its treatment and the risk of birth defects. We examined these associations using data from the National Birth Defects Prevention Study, a multi-site, population-based, case-control study.

METHODS

Analyses included 25,116 case and 9897 unaffected control infants with estimated delivery dates between 1997 and 2009. Information on autoimmune disease, medication use, and other pregnancy exposures was collected by means of telephone interview. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated for birth defects with five or more exposed cases; crude ORs and exact 95% CIs were estimated for birth defects with three to four exposed cases.

RESULTS

Autoimmune disease was reported by 373 mothers (279 case and 94 control mothers). The majority of birth defects evaluated were not associated with autoimmune disease; however, a statistically significant association between maternal autoimmune disease and encephalocele was observed (OR, 4.64; 95% CI, 1.95-11.04). Eighty-two mothers with autoimmune disease used an immune modifying/suppressing medication during pregnancy; this was associated with encephalocele (OR, 7.26; 95% CI, 1.37-24.61) and atrial septal defects (OR, 3.01; 95% CI, 1.16-7.80).

CONCLUSION

Our findings suggest maternal autoimmune disease and treatment are not associated with the majority of birth defects, but may be associated with some defects, particularly encephalocele. Given the low prevalence of individual autoimmune diseases and the rare use of specific medications, we were unable to examine associations of specific autoimmune diseases and medications with birth defects. Other studies are needed to confirm these findings. Birth Defects Research (Part A) 106:950-962, 2016. © 2016 Wiley Periodicals, Inc.

Maternal Antihypertensive Medication Use and Congenital Heart Defects: Updated Results From the National Birth Defects Prevention Study

Previous NBDPS (National Birth Defects Prevention Study) findings from 1997 to 2003 suggested that maternal antihypertensive use was associated with congenital heart defects (CHDs). We re-examined associations between specific antihypertensive medication classes and specific CHDs with additional NBDPS data from 2004 to 2011. After excluding mothers missing hypertension information or who reported pregestational diabetes mellitus, a multiple birth, or antihypertensive use but no hypertension, we compared self-reported maternal exposure data on 10 625 CHD cases and 11 137 nonmalformed controls. We calculated adjusted odds ratios [95% confidence intervals] to estimate the risk of specific CHDs associated with antihypertensive use during the month before conception through the third month of pregnancy, controlling for maternal age, race/ethnicity, body mass index, first trimester cigarette smoking, and NBDPS site. Overall, 164 (1.5%) case mothers and 102 (0.9%) control mothers reported early pregnancy antihypertensive use for their hypertension. We observed increased risk of 4 CHD phenotypes, regardless of antihypertensive medication class reported: coarctation of the aorta (2.50 [1.52-4.11]), pulmonary valve stenosis (2.19 [1.44-3.34]), perimembranous ventricular septal defect (1.90 [1.09-3.31]), and secundum atrial septal defect (1.94 [1.36-2.79]). The associations for these phenotypes were statistically significant for mothers who reported β-blocker use or renin-angiotensin system blocker use; estimates for other antihypertensive medication classes were generally based on fewer exposed cases and were less stable but remained elevated. Our results support and expand on earlier NBDPS findings that antihypertensive medication use may be associated with increased risk of specific CHDs, although we cannot completely rule out confounding by underlying disease characteristics.

Birth defects in infants born to employees of a microelectronics and business machine manufacturing facility

BACKGROUND

Concerns about solvent releases from a microelectronics/business machine manufacturing facility in upstate New York led to interest in the health of former workers, including this investigation of birth defects in children of male and female employees.

METHODS

Children born 1983 to 2001 to facility employees were enumerated and matched to New York State's Congenital Malformations Registry. Reported structural birth defects were compared with numbers expected from state rates (excluding New York City), generating standardized prevalence ratios (SPRs). Exposure assessors classified employees as ever/never potentially exposed at the facility to metals, chlorinated hydrocarbons, and other hydrocarbons during windows critical to organogenesis (female workers) or spermatogenesis (male workers). Among workers, adjusted prevalence ratios were generated to evaluate associations between potential exposures and specific birth defects.

RESULTS

External comparisons for structural defects were at expectation for infants of male workers (SPR = 1.01; 95% confidence interval [CI], 0.77-1.29; n = 60) and lower for births to female workers (SPR = 0.84; 95% CI, 0.50-1.33; n = 18). Among full-term infants of male workers, ventricular septal defects (VSDs) were somewhat elevated compared with the general population (SPR = 1.58; 95% CI, 0.99-2.39; n = 22). Within the cohort, potential paternal metal exposure was associated with increased VSD risk (adjusted prevalence ratio = 2.70; 95% CI, = 1.09-6.67; n = 7).

CONCLUSION

While overall SPRs were near expectation, paternal exposure to metals (primarily lead) appeared to be associated with increased VSD risk in infants. Take-home of occupational exposures, nonoccupational exposures, and chance could not be ruled out as causes. Case numbers for many defects were small, limiting assessment of the role of occupational exposures. Birth Defects Research (Part A) 106:696-707, 2016. © 2016 Wiley Periodicals, Inc.

Maternal asthma medication use during pregnancy and risk of congenital heart defects

BACKGROUND

Asthma affects 4% to 8% of pregnant women and studies suggest maternal asthma, particularly when uncontrolled, may be associated with adverse reproductive outcomes.

METHODS

We examined self-reported asthma medication use and the risk of congenital heart defects (CHD) in the National Birth Defects Prevention Study, a multi-center, population-based case-control study of selected major structural defects. We evaluated maternal use of bronchodilators and anti-inflammatories during the periconceptional period (1 month before conception through the first 3 pregnancy months) among 7638 infants with CHDs and 8106 nonmalformed controls with estimated delivery dates from 1997 to 2007. We used logistic regression to estimate odds ratios and 95% confidence intervals for 20 types of CHDs.

RESULTS

Among asthma medications reported during the periconceptional period among controls, albuterol accounted for 85.1% of all bronchodilator use, and fluticasone, prednisone, and montelukast accounted for 46.1%, 15.6%, and 14.9% of anti-inflammatory use, respectively. Of the women who reported bronchodilators during the periconceptional period, 71.1% reported use throughout pregnancy and only 29.4% reported concurrent use of an anti-inflammatory. We observed one statistically significant association between maternal bronchodilator use only and anomalous pulmonary venous return (odds ratio 2.3, 95% confidence interval 1.1-4.8) among numerous comparisons.

CONCLUSION

We did not observe statistically significant associations between the reported use of asthma medications during pregnancy and most specific types of CHDs. Despite limitations in our inability to evaluate asthma status and severity, our study suggests that maternal asthma medication use does not substantially, if at all, increase the risk of CHDs.

Extreme winter temperature and birth defects: a population-based case-control study

BACKGROUND/OBJECTIVE

We examined the relationship between extreme winter temperatures and birth defects to determine whether pregnant women might be vulnerable to the weather extremes expected with climate change.

METHODS

In this population-based, case-control study, we linked the New York State Congenital Malformations Registry to birth certificates (1992-2006). Cases were defined as live births with birth defects, and controls were selected from a 10% random sample of live births. We assigned meteorological data based on maternal birth residence and summarized universal apparent temperature across gestational weeks 3-8 (embryogenesis). We defined an extreme cold day as a day with mean temperature below the 10th percentile of the regional winter temperature distribution and a cold spell as 3 consecutive extreme cold days. We averaged temperature for each week of the first trimester to identify susceptible periods. We estimated adjusted odds ratios (ORs) and 95% confidence intervals (CIs) with multivariable logistic regression for 30 birth defects groups.

RESULTS

Among 13,044 cases and 59,884 controls with at least 1 week of embryogenesis in winter, coarctation of the aorta was associated with a 1°C decrease in mean universal apparent temperature (OR 1.06, 95% CI 1.02-1.11), cold spell (OR 1.61, 95% CI 1.11-2.34), and number of extreme cold days. We observed reduced odds of hypoplastic left heart syndrome and dislocated hip for some cold indicators.

CONCLUSIONS

Most birth defects were not associated with cold indicators; however, we found positive associations between cold indicators and coarctation of the aorta in the biologically-relevant developmental window which warrants replication.

Maternal butalbital use and selected defects in the national birth defects prevention study

BACKGROUND

Butalbital is a barbiturate contained in combination products with caffeine and an analgesic prescribed for the treatment of migraine and tension-type headaches. Controversy exists as to whether butalbital should continue to be prescribed in the United States because of the potential for abuse, overuse headache, and withdrawal syndromes. Butalbital crosses the placenta but there is limited information about potential teratogenicity.

OBJECTIVE

To evaluate associations between butalbital and a wide range of specific birth defects.

METHODS

The National Birth Defects Prevention Study is an ongoing, case-control study of nonsyndromic, major birth defects conducted in 10 states. The detailed case classification and large number of cases in the National Birth Defects Prevention Study allowed us to examine the association between maternal self-reported butalbital use and specific birth defects. We conducted an analysis of 8373 unaffected controls and 21,090 case infants with estimated dates of delivery between 1997 and 2007; included were birth defects with 250 or more cases. An exploratory analysis examined groups with 100 to 249 cases.

RESULTS

Seventy-three case mothers and 15 control mothers reported periconceptional butalbital use. Of 30 specific defect groups evaluated, adjusted odds ratios for maternal periconceptional butalbital use were statistically significant for 3 congenital heart defects: tetralogy of Fallot (adjusted odds ratio = 3.04; 95% confidence interval = 1.07-8.62), pulmonary valve stenosis (adjusted odds ratio = 5.73; 95% confidence interval = 2.25-14.62), and secundum-type atrial septal defect (adjusted odds ratio = 3.06; 95% confidence interval = 1.07-8.79). In the exploratory analysis, an elevated odds ratio was detected for 1 congenital heart defect, single ventricle.

CONCLUSIONS

We observed relationships between maternal periconceptional butalbital use and certain congenital heart defects. These associations have not been reported before, and some may be spurious. Butalbital use was rare and despite the large size of the National Birth Defects Prevention Study, the number of exposed case and control infants was small. However, if confirmed in additional studies, our findings will be useful in weighing the risks and benefits of butalbital for the treatment of migraine and tension-type headaches.

Excessive heat and respiratory hospitalizations in New York State: estimating current and future public health burden related to climate change

BACKGROUND

Although many climate-sensitive environmental exposures are related to mortality and morbidity, there is a paucity of estimates of the public health burden attributable to climate change.

OBJECTIVE

We estimated the excess current and future public health impacts related to respiratory hospitalizations attributable to extreme heat in summer in New York State (NYS) overall, its geographic regions, and across different demographic strata.

METHODS

On the basis of threshold temperature and percent risk changes identified from our study in NYS, we estimated recent and future attributable risks related to extreme heat due to climate change using the global climate model with various climate scenarios. We estimated effects of extreme high apparent temperature in summer on respiratory admissions, days hospitalized, direct hospitalization costs, and lost productivity from days hospitalized after adjusting for inflation.

RESULTS

The estimated respiratory disease burden attributable to extreme heat at baseline (1991-2004) in NYS was 100 hospital admissions, US$644,069 in direct hospitalization costs, and 616 days of hospitalization per year. Projections for 2080-2099 based on three different climate scenarios ranged from 206-607 excess hospital admissions, US$26-$76 million in hospitalization costs, and 1,299-3,744 days of hospitalization per year. Estimated impacts varied by geographic region and population demographics.

CONCLUSIONS

We estimated that excess respiratory admissions in NYS due to excessive heat would be 2 to 6 times higher in 2080-2099 than in 1991-2004. When combined with other heat-associated diseases and mortality, the potential public health burden associated with global warming could be substantial.

A population-based case-control study of extreme summer temperature and birth defects

BACKGROUND

Although hyperthermia is a recognized animal teratogen and maternal fever has been associated with birth defects in humans, data on the relationship between high environmental temperatures and birth defects are limited.

OBJECTIVE

To determine whether pregnancies are potentially vulnerable to the weather extremes anticipated with climate change, we evaluated the relationship between extreme summer temperature and the occurrence of birth defects.

METHODS

We performed a population-based case-control study by linking the New York State Congenital Malformations Registry to birth certificates for the years 1992-2006. We selected nonmalformed infants from a 10% random sample of live births as controls. We assigned meteorologic data based on maternal residence at birth, summarized universal apparent temperature (UAT; degrees Fahrenheit) across the critical period of embryogenesis, and estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) with multivariable logistic regression, controlling for confounders available on the birth certificate.

RESULTS

Among 6,422 cases and 59,328 controls that shared at least 1 week of the critical period in summer, a 5-degree increase in mean daily minimum UAT was significantly associated with congenital cataracts (aOR = 1.51; 95% CI: 1.14, 1.99). Congenital cataracts were significantly associated with all ambient temperature indicators as well: heat wave, number of heat waves, and number of days above the 90th percentile. Inconsistent associations with a subset of temperature indicators were observed for renal agenesis/hypoplasia (positive) and anophthalmia/microphthalmia and gastroschisis (negative).

CONCLUSIONS

We found positive and consistent associations between multiple heat indicators during the relevant developmental window and congenital cataracts which should be confirmed with other data sources.