Assessing pregnant women's compliance with different alcohol guidelines: an 11-year prospective study

To assess women's compliance with different Australian guidelines on alcohol intake during pregnancy and examine factors that might influence compliance.

We analysed prospective, population-based data on women aged 22-33 years who were pregnant before October 2001, when guidelines recommended zero alcohol (n = 419), or were first pregnant after October 2001, when guidelines recommended low alcohol intake (n = 829). Data were obtained from surveys conducted in 1996, 2000, 2003 and 2006 as part of the Australian Longitudinal Study on Women's Health.

Relative risks (RRs) for zero alcohol intake, low alcohol intake and compliance with alcohol guidelines, estimated by a modified Poisson regression model with robust error variance.

About 80% of women consumed alcohol during pregnancy under zero and low alcohol guidelines. Compliance with zero alcohol guidelines or low alcohol guidelines (up to two drinks per day and less than seven drinks per week) was the same for women who were pregnant before October 2001 and women who were first pregnant after October 2001 (20% v 17% for compliance with zero alcohol guidelines, P > 0.01; 75% v 80% for compliance with low alcohol guidelines, P > 0.01). Over 90% of women drank alcohol before pregnancy and prior alcohol intake had a strong effect on alcohol intake during pregnancy, even at low levels (RR for zero alcohol, 0.21 [95% CI, 0.16-0.28]; RR for low alcohol, 0.91 [95% CI, 0.86-0.96]). RR for compliance with guidelines was 3.54 (95% CI, 2.85-4.40) for women who were pregnant while low alcohol intake was recommended, compared with those who were pregnant while zero alcohol guidelines were in place.

The October 2001 change in alcohol guidelines does not appear to have changed behaviour. Risks associated with different levels of alcohol intake during pregnancy need to be clearly established and communicated.