Obstetric and perinatal outcomes in pregnancies associated with illicit substance abuse

To determine the obstetric and perinatal outcomes of women using illicit drugs during pregnancy by substance group.

A retrospective audit of obstetric and perinatal outcomes in women who used opiates or amphetamines during their pregnancy and delivered at King Edward Memorial Hospital (KEMH), Perth, Australia between December 1997 and April 2000 was performed. Maternal, fetal and neonatal parameters were assessed. These were compared with obstetric and perinatal data recorded by the Health Department of Western Australia (HDWA) for the 25,291 deliveries of 25,677 infants in 1998.

Between December 1997 and April 2000 91 opiate-using and 50 amphetamine-using women were identified and included in the analysis. Both groups of drug-using women were younger (opiates P = 0.001, amphetamines P = 0.001) than the general population. There was a higher incidence of aboriginality (P = 0.001) in the amphetamine group. In the opiate-using group multiparity (P = 0.0001) and anaemia (P = 0.0001) were higher. Illicit drug-using women had a higher incidence of hepatitis C (opiates P = 0.001, amphetamines P = 0.003), and a greater need for pharmacological analgesia for labour and delivery (opiates P = 0.007, amphetamines P = 0.042). Their infants were significantly more likely to deliver at less than 37 weeks' gestation (opiates P = 0.0001, amphetamines P = 0.001), to have a birthweight of less than 2.5 kg (P = 0.0001), be small for gestational age and require admission to the special care nursery (P = 0.0001). Infants born to women in the amphetamine group were more likely to have an Apgar score < 7 (P = 0.0001) recorded. Infants of women in the opiate group required more resuscitation (P = 0.05).

Women who use illicit drugs are more likely to experience adverse obstetric and perinatal outcomes than women in the general population. Differences are seen depending on the type of illicit drug used. These findings need to be replicated in a larger prospective cohort to highlight management requirements of these women and their infants. Further information is required about the effects of amphetamines in pregnancy.