Alcohol exposure prior to pregnancy—does hazardous consumption affect placenta‐ and inflammatory‐mediated pregnancy outcomes? A Swedish population‐based cohort study

INTRODUCTION: Alcohol consumption during pregnancy is related to severe birth complications such as low birthweight, preterm birth and birth defects. During the last decade, the Alcohol Use Disorders Identification Test (AUDIT) has been used as a screening tool in Swedish maternal healthcare units to identify hazardous, pre‐pregnancy alcohol use. However, evaluation of the screening with AUDIT, as well as adverse maternal or neonatal outcomes, has not been assessed at a national level. MATERIAL AND METHODS: This was a population‐based cohort study of 530 458 births from 2013 to 2018 using demographic, reproductive and maternal health data from the Swedish Pregnancy Register. Self‐reported alcohol consumption in the year before pregnancy, measured as AUDIT scores, was categorized into moderate (6–13 points) and high‐risk (14–40 points) consumption, with low‐risk (0–5 points) consumption as the reference group. Associations with pregnancy‐ and birth outcomes were explored with logistic regressions using generalized estimating equation models, adjusting for maternal and socioeconomic characteristics. Estimates are presented as adjusted odds ratios (aORs) with 95% confidence intervals (CIs). RESULTS: High‐risk and moderate pre‐pregnancy alcohol consumption was associated with preeclampsia, preterm birth and birth of an infant small for gestational age (SGA), but these associations were nonsignificant after adjustments. Prior moderate‐risk (aOR 1.29, 95% CI 1.17–1.42) and high‐risk consumption (aOR 1.62, 95% CI 1.17–2.25) increased the likelihood of intrapartum and neonatal infections. CONCLUSIONS: Apart from identifying hazardous alcohol consumption prior to pregnancy and the offer of counseling, screening with the AUDIT in early pregnancy indicates a high risk of inflammatory‐/placenta‐mediated pregnancy and birth outcomes. For most outcomes, AUDIT was not an independent contributor when adjusting for confounding factors. Hazardous alcohol use prior to pregnancy was independently linked to intrapartum and neonatal infections; conditions associated with morbidity and long‐term sequalae. These associations may be explained by alcohol‐induced changes in the maternal or fetal immune system in early pregnancy or persistent alcohol intake during pregnancy, or may depend on unidentified confounding factors.