Fetal motility and chronic exposure to antiepileptic drugs

The potential influence of antiepileptic drugs (AEDs) on fetal CNS function was studied with respect to motility patterns. Quantitative and qualitative aspects of spontaneous fetal activity were investigated for chronic AED-exposed fetuses and controls at three intervals during pregnancy: i.e. 20, 32 and 38 weeks. Movements were observed applying real-time ultrasound. Third trimester rest-activity cycles were determined according to the fetal behavioural state concept. Quantitative analysis revealed no marked differences in gross fetal motility between AED-exposed fetuses and controls. Both groups demonstrated the same developmental trend from midterm towards the third trimester. The number of trunk movements decreased, while their median duration increased. The incidence of fetal eye movements during C2F was lower for AED-exposed fetuses than for controls (significant for 38 weeks). In qualitative analysis, general movements of AED-exposed fetuses were more often labeled as suspect or abnormal than those of control fetuses (respectively, 8 out of 31 and 1 out of 20; P = 0.06). Future studies concerning chronic fetal AED-exposure and fetal CNS function should focus on qualitative rather than quantitative aspects of motility.