Drug misuse in pregnancy: losing sight of the baby?

Maternal drug misuse can seriously affect the health of the fetus and newborn infant. The association of maternal drug misuse with prematurity, intrauterine growth restriction (IUGR) and neonatal abstinence syndrome (NAS) is well recognised, and there is growing concern about infant visual development and longer-term neurodevelopmental outcome. Drug misuse is associated with changes in the visual system as measured by the visual evoked potential (VEP) in adults and animal models. A recent study has shown abnormal VEPs in newborn infants exposed to methadone in utero, consistent with reports of delayed visual development in this population. Since visual abnormalities and neurodevelopmental abnormalities can be predicted by abnormal VEPs in infancy, it is postulated that the VEP may be a valuable tool in the detection of the adverse effects of maternal drug misuse upon the infant. This review summarises the impact of maternal drug misuse upon the health of the fetus and newborn infant, addresses the specific effects of maternal drug misuse upon the developing visual system and discusses the potential role of the VEP in the assessment of these infants.