Illicit drug use before and during pregnancy at a tertiary maternity hospital 2000-2006

To study the prevalence of use of illicit drugs by women of reproductive age before and during pregnancy and the changes in rates of illicit drug use in pregnancy over recent years.

All pregnant women attending the public antenatal clinic over a 7 year period (2000-2006) were routinely interviewed about their use of illicit drugs by a midwife at the antenatal booking visit.

Records for 25,049 women, who self-reported previous and current use of cannabis, amphetamines, ecstasy and heroin, were included in the study.

Cannabis was the most common illicit drug used before and during pregnancy; 9.3% of women were engaged in regular use prior to pregnancy and 2.5% were users during pregnancy. A very low proportion of women reported use of amphetamines, ecstasy or heroin in pregnancy. There was an increase in ever regular use and any past use of cannabis, amphetamines and ecstasy over time.

The prevalence of illicit drug use by young women prior to becoming pregnant is of concern. While pregnancy appears to be a strong motivator for women to cease substance use, there is a need to study whether women resume drug use after their baby is born.