Association Between Alcohol use in Pregnancy and Preeclampsia or Hypertension in Pregnancy: A Systematic Review

Abstract BackgroundTo summarize evidence on the association of maternal alcohol consumption during pregnancy with preeclampsia (PE) or hypertensive disorders of pregnancy (HDP).Methods We searched PubMed, EMBASE, PsycINFO, and Cochrane Central Register of Controlled Trials databases. We included original studies that presented relative risks, odds ratios, or data to calculate the risks for the association of alcohol consumption during pregnancy with PE or HDP. We used the Newcastle-Ottawa Scale to assess study quality. We conducted a random-effects meta-analysis to calculate the pooled association of gestational alcohol use with PE or HDP.ResultsThirty-seven articles met the criteria for inclusion. The total study population was 4,434,003 women with 170,481 cases of PE and 467,055 women with 41,708 cases of HDP. For all included studies, there was no significant association between alcohol consumption during pregnancy and incidence of PE (OR=0.93, 95%CI: 0.73-1.20), with statistical significant heterogeneity (I2=91%, P<0.00001). Among the subgroup of prospective cohort studies, the pooled results showed that alcohol consumption during pregnancy had a protective effect on PE (OR=0.64, 95% CI: 0.54-0.76), and with no statistical heterogeneity (I2 =0%, P=0.56). The results from the subgroup of retrospective cohort and case-control studies showed that alcohol consumption during pregnancy was not associated with PE, with odds ratios of 1.07 (0.65-1.74) and 1.02 (0.64-1.61), respectively, and with statistically significant heterogeneity. The pooled OR for the association between alcohol consumption during pregnancy and HDP was 0.98 (95% CI: 0.75-1.29), with considerable heterogeneity (I2=90% P<0.00001).ConclusionOverall, there is no apparent association of alcohol consumption during pregnancy with PE or HDP. In prospective cohort studies, an evident protective effect is likely due to residual confounding. Further studies should consider alternative designs such as mendelian randomization, which can overcome some of the limitations of conventional prospective studies.