Heavy prenatal alcohol exposure and increased risk of stillbirth

Abstract

Objective: To investigate the association between heavy prenatal alcohol exposure and stillbirth. Design: Data linkage cohort study. Setting: Western Australia (WA). Population: The exposed cohort included mothers with an alcohol-related diagnosis (International Classification of Diseases, ninth/tenth revisions) recorded in health data sets and all their offspring born in WA (1983–2007). Mothers without an alcohol-related diagnosis and their offspring comprised the comparison cohort. Methods: Exposed and comparison mothers were identified through the WA Data Linkage System. Odds ratios for stillbirth at 20 + weeks of gestation were estimated by logistic regression, stratified by Aboriginal status. Main outcome measures: The proportion of stillbirths at 20 + weeks of gestation is presented per 1000 births, as well as adjusted odds ratios (aOR) and 95% confidence intervals (95% CI), and population-attributable fractions. Results: Increased odds of stillbirth were observed for mothers with an alcohol-related diagnosis at any stage of their life for both non-Aboriginal (aOR 1.36; 95% CI 1.05–1.76) and Aboriginal (aOR 1.33; 95% CI 1.08–1.64) births. When an alcohol diagnosis was recorded during pregnancy, increased odds were observed for non-Aboriginal births (aOR 2.24; 95% CI 1.09–4.60), with the highest odds of Aboriginal stillbirth occurring when an alcohol diagnosis was recorded within 1 year postpregnancy (aOR 2.88; 95% CI 1.75–4.73). The population-attributable fractions indicate that 0.8% of non-Aboriginal and 7.9% of Aboriginal stillbirths are the result of heavy alcohol consumption.Conclusions: Prevention of heavy maternal alcohol use has the potential to reduce stillbirths. The lack of an association between exposure during pregnancy and Aboriginal stillbirth in this study needs further investigation.