Maternal periconceptional alcohol consumption and risk for conotruncal heart defects.

BACKGROUND

In this study we investigated whether the risk of delivering infants with conotruncal heart defects was increased among mothers who consumed alcohol during the periconceptional period (i.e., 1 month before conception to 3 months after conception).

METHODS

Data were obtained from a population-based case-control study of California births from 1987-1988. Information concerning alcohol consumption was obtained via telephone interviews with mothers of 207 (87% of eligibles) case infants and 481 (76%) nonmalformed control infants.

RESULTS

Bivariate results indicated that relative to nonconsumers, women who consumed alcohol less than once a week had a 1.3-fold increased risk of delivering infants with a conotruncal heart defect (95% confidence interval (CI) 1.0, 1.9), and women who consumed alcohol once a week or more had a 1.9-fold increased risk (95% CI 1.0, 3.4). The risks associated with consuming five or more drinks per drinking occasion were 1.6 (95% CI 0.8, 3.2) for less than once a week, and 2.4 for once a week or more (95% CI 0.6, 9.7). The results for the phenotypic subgroups were similar to those for all cases. Adjustment for potential covariates resulted in somewhat weaker, but still elevated, risks.

CONCLUSIONS

This study found that the risk of conotruncal heart defects in offspring was moderately elevated among women who consumed alcoholic beverages during the periconceptional period, and that risk was higher with increased frequency of drinking or increased number of drinks consumed per occasion. Most of the risk estimates were imprecise, and chance could not be ruled out as an explanation for the observed findings.