Background: High alcohol intake in pregnancy has been linked to abnormal fetal development. There are limited published data in Australia on standard drinks of alcohol consumed on a typical occasion during the periconceptional period or pregnancy.
Methods: During 1995 to 1997, a 10% random sample of all nonindigenous women giving birth in Western Australia was surveyed 12 weeks after delivery (N=4,839). Women were asked questions about alcohol consumption in each of the 4 time periods: the 3 months before pregnancy and each trimester of pregnancy. Questions were framed to measure volume, frequency, and type of alcoholic beverage.
Results: 46.7% of the women had not planned their pregnancy. Most women (79.8%) reported drinking alcohol in the 3 months before pregnancy, with 58.7% drinking alcohol in at least 1 trimester of pregnancy. The proportion of women consuming 1 to 2 drinks on a typical occasion did not change much during pregnancy, but the number of occasions declined. Although the proportion of women consuming more than 2 standard drinks on a typical occasion declined after the first trimester, 19.0% of women consumed this amount in at least 1 trimester of pregnancy and 4.3% of women consumed 5 or more standard drinks on a typical occasion in at least 1 trimester of pregnancy. In the first trimester of pregnancy, 14.8% of women drank outside the current Australian guideline for alcohol consumption in pregnancy, decreasing to 10% in the second and third trimesters.
Conclusions: Women generally reduced their average alcohol consumption and the number of standard drinks on a typical occasion as their pregnancy progressed, although 10 to 14% were drinking outside current guidelines for pregnancy. It is important that all women of child-bearing age are aware, well before they consider pregnancy, of the risks of drinking alcohol during pregnancy so they can make informed decisions about their alcohol consumption in pregnancy.