It is difficult accurately to estimate the prevalence of high-risk drug use during pregnancy for a variety of reasons: feelings of shame, denial and stigma experienced by the drug user, lack of awareness among professionals in antenatal services, the presence of comorbid psychiatric disorders, and sociocultural barriers that prevent a thorough assessment. However, we know that about one-third of drug users in treatment in the UK are female, and over 90% of these women are of childbearing age (15–39 years). A number of large surveys of drug use in different populations conducted in the USA provide a further insight. For example, the National Pregnancy and Health Survey gathered self-report data from a sample of 2613 women whose babies were delivered in 52 urban and rural hospitals during 1992 (National Institute of Drug Abuse, 1996). Over 5% of those who gave birth during the study period had used illicit drugs while they were pregnant, with 2.9% using cannabis and 1.1% using cocaine at some point in their pregnancy (compared with 20% smoking tobacco and 18.5% drinking alcohol). A further report combined 2 years of US National Household Survey data (1994 and 1995) for women and girls 15–44 years old and found that 9.3% reported current use of illicit drugs, with 2.3% doing so while pregnant. The problem is therefore a significant one, particularly as it has implications for both mother and child.