Alcohol consumption and binge drinking in early pregnancy. A cross-sectional study with data from the Copenhagen Pregnancy Cohort.

BACKGROUND Since 2007 the Danish Health and Medicines Authority has advised total alcohol abstinence from the time of trying to conceive and throughout pregnancy. The prevalence of binge drinking among pregnant Danish women has nevertheless been reported to be up to 48 % during early pregnancy. Since the introduction of the recommendation of total abstinence, no studies have examined pre-pregnancy lifestyle and reproductive risk factors associated with this behaviour in a Danish context. The aims of this study were therefore to describe the prevalence of weekly alcohol consumption and binge drinking in early pregnancy among women living in the capital of Denmark. Secondly to identify pre-pregnancy lifestyle and reproductive risk factors associated with binge drinking during early pregnancy. METHODS Data were collected from September 2012 to August 2013 at the Department of Obstetrics, Rigshospitalet, Copenhagen, Denmark. Self-reported information on each woman's socio-demographic characteristics, medical history, and lifestyle factors including alcohol habits was obtained from an electronic questionnaire filled out as part of the individual medical record. Descriptive analysis was conducted and multivariate logistic regression analysis was used to assess the potential associated risk factors (adjusted odds ratio (aOR)). RESULTS Questionnaires from 3,238 women were included. A majority of 70 %, reported weekly alcohol consumption before pregnancy. The prevalence decreased to 3 % during early pregnancy. The overall proportion of women reporting binge drinking during early pregnancy was 35 % (n = 1,134). The following independent risk factors for binge drinking in early pregnancy were identified: lower degree of planned pregnancy, smoking and alcohol habits before pregnancy ((1 unit/weekly aOR 4.48, CI: 3.14 - 6.40), (2-7 units aOR 10.23, CI: 7.44-14.06), (≥8 units aOR 33.18, CI: 19.53-56.36)). Multiparity and the use of assisted reproductive technology were associated with lower odds of binge drinking in early pregnancy. CONCLUSION The prevalence of weekly alcohol consumption decreased considerably during early pregnancy compared with pre-pregnancy levels. Nevertheless one third of the pregnant women engaged in binge drinking. Identification of risk factors for this behaviour renders it possible not only to design prevention strategies, but also to target those most at risk.