BACKGROUND: Controversies still exist regarding the existence of a 'safe' level of alcohol intake during pregnancy. The aim of this study was to assess the risk of fetal death (spontaneous abortion and stillbirth) according to maternal alcohol consumption in a large Danish pregnancy cohort.
METHODS: A cohort study carried out within the framework of the Danish National Birth Cohort. A total of the 92 719 participants enrolled in the Danish National Birth Cohort who provided information about lifestyle during first trimester of pregnancy were included in the study. Information about average weekly consumption of alcohol during pregnancy, smoking, coffee drinking, occupational status and reproductive history were obtained by means of computer-assisted telephone interviews. Pregnancy outcomes (spontaneous abortion, stillbirth, live birth and other pregnancy outcome) and gestational age at end of pregnancy were obtained through register linkage with the Civil Registration System and the National Discharge Registry. Data were analysed using Cox regression models, taking the varying gestational age at recruitment and time-dependent co-variables into account.
RESULTS: Fifty-five per cent of the participants abstained from alcohol drinking during pregnancy and only 2.2% reported four or more drinks per week. The adjusted hazard ratios for fetal death in first trimester were 1.66 [95% confidence interval (CI) 1.43-1.92] and 2.82 (95% CI 2.27-3.49) for women who reported 2-3½ drinks per week and 4 or more drinks per week, respectively, and 1.57 (95% CI 1.30-1.90) and 1.73 (95% CI 1.24-2.41) for fetal death during pregnancy weeks 13-16. No increased risk was found for fetal death after 16 weeks of pregnancy.
CONCLUSIONS: Even low amounts of alcohol consumption during early pregnancy increased the risk of spontaneous abortion substantially. The results indicate that the fetus is particularly susceptible to alcohol exposure early in pregnancy.
BACKGROUND: The safety of small amounts of alcohol drinking and occasional binge-level drinking during pregnancy remains unsettled. We examined the association of maternal average alcohol intake and binge drinking (>or=5 drinks per sitting) with infant mortality, both in the neonatal and postneonatal period.
METHODS: Participants were 79,216 mothers who were enrolled in the Danish National Birth Cohort in 1996-2002, gave birth to a live-born singleton, and provided information while they were pregnant on alcohol consumption during pregnancy. Information on infant mortality and causes of death was obtained from national registries and medical records.
RESULTS: During the first year of life, 279 children (0.35%) died, 204 during the neonatal period. Infant mortality was not associated with alcohol drinking, even at a consumption level of either 4+ drinks per week or 3+ occasions of binge drinking. Postneonatal mortality was associated with an intake of 4+ drinks per week (hazard ratio = 3.56 [95% confidence interval = 1.15-8.43]) and with 3+ binge episodes (2.69 [1.27-5.69]). When restricting analyses to term births, both infant mortality and postneonatal mortality were associated with a weekly average intake of 4+ drinks or 3+ binge episodes.
CONCLUSIONS: Among term infants, intake of at least 4 drinks of alcohol per week or binging on 3 or more occasions during pregnancy are associated with an increased risk of infant mortality, especially during the postneonatal period.
BACKGROUND: Controversies still exist regarding the existence of a 'safe' level of alcohol intake during pregnancy. The aim of this study was to assess the risk of fetal death (spontaneous abortion and stillbirth) according to maternal alcohol consumption in a large Danish pregnancy cohort.
METHODS: A cohort study carried out within the framework of the Danish National Birth Cohort. A total of the 92 719 participants enrolled in the Danish National Birth Cohort who provided information about lifestyle during first trimester of pregnancy were included in the study. Information about average weekly consumption of alcohol during pregnancy, smoking, coffee drinking, occupational status and reproductive history were obtained by means of computer-assisted telephone interviews. Pregnancy outcomes (spontaneous abortion, stillbirth, live birth and other pregnancy outcome) and gestational age at end of pregnancy were obtained through register linkage with the Civil Registration System and the National Discharge Registry. Data were analysed using Cox regression models, taking the varying gestational age at recruitment and time-dependent co-variables into account.
RESULTS: Fifty-five per cent of the participants abstained from alcohol drinking during pregnancy and only 2.2% reported four or more drinks per week. The adjusted hazard ratios for fetal death in first trimester were 1.66 [95% confidence interval (CI) 1.43-1.92] and 2.82 (95% CI 2.27-3.49) for women who reported 2-3½ drinks per week and 4 or more drinks per week, respectively, and 1.57 (95% CI 1.30-1.90) and 1.73 (95% CI 1.24-2.41) for fetal death during pregnancy weeks 13-16. No increased risk was found for fetal death after 16 weeks of pregnancy.
CONCLUSIONS: Even low amounts of alcohol consumption during early pregnancy increased the risk of spontaneous abortion substantially. The results indicate that the fetus is particularly susceptible to alcohol exposure early in pregnancy.