Association between maternal periconceptional alcohol consumption and neural tube defects: Findings from the National Birth Defects Prevention Study, 1997-2011.

BACKGROUND: Neural tube defects (NTD)s are common birth defects with a multifactorial etiology. Findings from human studies examining environmental (non-inherited) exposures tend to be inconclusive. In particular, although animal studies of alcohol exposure and NTDs support its teratogenic potential, human studies are equivocal. Using data from the National Birth Defects Prevention Study (NBDPS), associations between maternal periconceptional (1 month before through 1 month after conception) alcohol consumption and NTDs in offspring were examined. METHODS: NTD cases and unaffected live born singleton controls with expected dates of delivery from October 1997-December 2011 were enrolled in the NBDPS. Interview reports of alcohol consumption (quantity, frequency, variability, type) from 1,922 case and 11,251 control mothers were analyzed. Crude and adjusted odds ratios (aOR)s and 95% confidence intervals (CI)s for alcohol consumption and all NTDs combined and selected subtypes (spina bifida, anencephaly, encephalocele) were estimated using unconditional logistic regression analysis. RESULTS: Among mothers in the NBDPS, 28% of NTD case and 35% of control mothers reported any periconceptional alcohol consumption. For each measure of alcohol consumption, inverse associations were observed for all NTDs combined (aORs = 0.6-1.0). Results for NTD subtypes tended to be similar, but CIs for spina bifida and encephalocele were more likely to include the null. CONCLUSIONS: These findings suggest a lack of positive associations between maternal periconceptional alcohol consumption and NTDs. Future studies should continue to evaluate the association between maternal alcohol consumption and NTDs in offspring accounting for methodological limitations such as potential misclassification from self-reported alcohol consumption.

Age at onset of first signs or symptoms predicts age at loss of ambulation in Duchenne and Becker Muscular Dystrophy: Data from the MD STARnet.

PURPOSE: We investigated the prognostic utility of onset age at first signs and symptoms (SS) to predict onset age at loss of ambulation (LOA) for childhood-onset Duchenne and Becker Muscular Dystrophies (DBMD). METHODS: Our cohort comprised male cases with DBMD ascertained by the population-based Muscular Dystrophy Surveillance, Tracking, and Research Network (MD STARnet). Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models for associations between onset ages of first SS and LOA. Covariates controlled for were corticosteroid use, family history of DBMD, birth year, race/ethnicity, and MD STARnet site. Onset age at first SS was considered as a continuous and as a categorical variable. RESULTS: A one-year increase in onset age at first SS was significantly associated with a 10% reduction in annual risk of LOA (HR = 0.90, CI = 0.87-0.94). Treating onset age at first SS as a categorical variable yielded a similar association (≥ 5 years: referent; ≥ 3 to < 5 years: HR = 1.36, CI = 1.02-1.81; 18 months to < 3 years: HR = 1.72, CI = 1.31-2.26; < 18 months: HR = 1.52, CI = 1.14-2.02). CONCLUSIONS: Earlier onset age at first SS is associated with earlier onset age at LOA and may have clinical utility in differentiating childhood-onset Duchenne and Becker muscular dystrophies.

Maternal periconceptional alcohol consumption and congenital heart defects.

BACKGROUND: Congenital heart defects (CHDs) are the leading cause of infant death from birth defects. Animal studies suggest in utero alcohol exposure is a teratogen for cardiogenesis; however, results from epidemiologic studies are mixed. METHODS: Data from the National Birth Defects Prevention Study were used to estimate associations between CHDs and case (n = 7076) and control (n = 7972) mother reports of periconceptional (1 month before pregnancy through the first trimester) alcohol consumption with expected delivery dates during 1997 to 2007. CHDs were examined by category (conotruncal, septal, left ventricular outflow tract obstruction, and right ventricular outflow tract obstruction, heterotaxy with CHD) and subtype (e.g., tetralogy of Fallot [TOF]). Alcohol measures examined were any consumption, maximum average drinks per month, binge drinking, and alcohol type. Adjusted odds ratios and 95% confidence intervals were estimated using unconditional logistic regression analysis. RESULTS: Increased risks, albeit marginally statistically significant, were observed for TOF and each maternal alcohol measure examined and for right ventricular outflow tract obstruction and heterotaxy with CHD and consumption of distilled spirits. Significantly reduced risks were observed for several CHD categories (septal defects, left ventricular outflow tract obstruction, and right ventricular outflow tract obstruction) and some corresponding subtypes with different alcohol measures. Significant risks were not observed for the other CHDs examined. CONCLUSION: Analysis of this large, well-defined study sample did not show statistically significant increased risks between measures of maternal alcohol consumption and most CHDs examined. These findings may reflect, in part, limitations with retrospective exposure assessment or unmeasured confounders. Additional studies with continued improvement in measurement of alcohol consumption are recommended.

Next steps for birth defects research and prevention: The birth defects study to evaluate pregnancy exposures (BD-STEPS).

BACKGROUND: The Birth Defects Study To Evaluate Pregnancy exposureS (BD-STEPS) is a population-based, multi-Center case-control study of modifiable risk factors for selected birth defects in the United States. BD-STEPS is the second major research effort of the Centers for Birth Defects Research and Prevention, which extends and expands the initial research effort, the National Birth Defects Prevention Study (NBDPS). METHODS: BD-STEPS focuses on 17 categories of structural birth defects selected based on severity, prevalence, consistent ascertainment, and previous findings that warrant additional research. Cases are identified through existing birth defects surveillance programs; controls are from vital records or birth hospital logs from the same catchment area. BD-STEPS uses a standardized computer-assisted telephone interview to collect information from case and control mothers on topics including demographics, health conditions, and medication use. Following the maternal interview, selected Centers request permission to sample residual newborn screening blood spots from state repositories for genetic analyses. New components planned for BD-STEPS include linkages with external datasets and use of online questionnaires to collect in-depth information on selected exposures. RESULTS: BD-STEPS extends NBDPS by continuing to collect data on many exposures that were assessed in NBDPS, allowing data from both studies to be combined and providing an unprecedented sample size to analyze rare exposures. BD-STEPS expands upon NBDPS by collecting more detailed information on existing exposures as well as new exposures. CONCLUSION: The goal of BD-STEPS is to provide women and healthcare providers with information they need to make decisions to promote the healthiest pregnancy possible.

Genitourinary health in a population-based cohort of males with Duchenne and Becker Muscular dystrophies.

INTRODUCTION: Genitourinary (GU) health among patients with Duchenne and Becker muscular dystrophies (DBMD) has not been explored using population-based data. METHODS: Medical records of 918 males ascertained by the Muscular Dystrophy Surveillance, Tracking, and Research Network were reviewed for documentation of GU-related hospitalizations and prescribed medications. Percentages of males who received these medical interventions were calculated, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for associations with sociodemographics (study site, race/ethnicity), symptoms (early- vs. late-onset, ambulation status, scoliosis), and treatments (respiratory support, steroids). RESULTS: Among the 918 males, 81 (9%) had a GU condition, with voiding dysfunction (n = 40), GU tract infection (n = 19), and kidney/ureter calculus (n = 9) most frequently seen. The Kaplan-Meier curve produced a cumulative probability of 27%. Cox regression showed GU conditions were more common when males were non-ambulatory (HR 2.7, 95% CI 1.3-5.6). CONCLUSIONS: Our findings highlight the need for increased awareness of GU health and multidisciplinary care of DBMD patients.

Maternal periconceptional alcohol consumption and congenital limb deficiencies.

BACKGROUND: Women of childbearing age report high rates of alcohol consumption, which may result in alcohol exposure during early pregnancy. Epidemiological research on congenital limb deficiencies (LDs) and periconceptional exposure to alcohol is inconclusive. METHODS: Data from the National Birth Defects Prevention Study (NBDPS) were examined for associations between LDs and patterns of maternal periconceptional (1 month before conception through the first trimester) alcohol consumption among LD case (n = 906) and unaffected control (n = 8352) pregnancies with expected delivery dates from 10/1997 through 12/2007. Adjusted odds ratios (aORs) and 95% confidence intervals were estimated from unconditional logistic regression analysis for all LDs combined, specific LD subtypes (preaxial/terminal transverse), and LD anatomic groups (upper/lower limbs); interactions with folic acid (FA) supplementation were tested. RESULTS: When compared with nondrinkers, inverse associations were found between all LDs combined, preaxial, and upper LDs and any reported periconceptional alcohol consumption (aORs ranged from 0.56-0.83), drinking without binging (aORs: 0.53-0.75), and binge drinking (≥4 drinks/occasion) (aORs: 0.64-0.94); however, none of the binge drinking aORs were statistically significant. Stratification by alcohol type showed inverse associations between all LDs combined, preaxial, transverse, and upper and lower LDs for drinking without binging of wine only (aORs: 0.39-0.67) and between all LDs combined and upper LDs for drinking without binging of combinations of alcohol (aORs: 0.63-0.87). FA did not modify observed associations. CONCLUSION: Maternal periconceptional alcohol consumption did not emerge as a teratogen for selected LDs in the NBDPS. Future studies should evaluate additional rare LDs among more highly exposed populations.