Objectives Alcohol consumption during pregnancy potentially has significant effects on both mother and baby. The aim of the study was to determine the effectiveness of a brief intervention to reduce alcohol consumption during pregnancy.

Methods This study was performed at the outpatient antenatal clinics of a large academic maternity teaching hospital in Dublin city centre. Six hundred and fifty-six women who drank alcohol before pregnancy were recruited at their first antenatal clinic visit. Drinking patterns before pregnancy, since becoming pregnant, and in later pregnancy (at ~32 weeks of gestation) were assessed using the Alcohol Use Disorders Identification Test (AUDIT). A controlled study was conducted – participants were allocated to either the brief intervention group (screening and 5 minutes of non-directive discussion of their drinking pattern) or a control group (screening and treatment as usual).

Results Before pregnancy, 57% of women consumed five or more units of alcohol per drinking occasion (i.e. binge drinking); during pregnancy, the rate of binge drinking fell to 4.8%. Sixty per cent of women who drank before pregnancy ceased drinking when pregnant, and a further 9% reduced their intake substantially. Four hundred and ninety-nine women were followed up in later pregnancy. The brief intervention did not produce any significant reduction in alcohol consumption above that attributable to pregnancy and comprehensive screening in antenatal care. Larger reductions in alcohol intake during pregnancy were associated with younger age, non-Irish nationality and greater intake of alcohol before first antenatal clinic visit.

Conclusion Pregnancy itself produces abstinence and large reductions in alcohol consumption, even among women who drink relatively heavily. Consequently, a universal screening and brief intervention programme is not warranted but screening and targeted interventions could be appropriate such as repeated interventions for those who continue to binge drink. Future research could include evaluating interventions for those women who continue to binge drink during pregnancy and exploring ways of maintaining reductions in alcohol consumption among women who decreased consumption during pregnancy.