Serum phenytoin during pregnancy, labor and puerperium


Department of Clinical Pharmacology University of Helsinki paasikivenkatu 4 00250 Helsinki Finland


111 pregnancies of epileptic women on phenytoin therapy were observed in a prospective study. Maternal serum phenytoin concentrations were measured monthly or biweekly during pregnancy, labor and puerperium. The concentration decreased towards the end of pregnancy and was lowest at delivery. In 48% of the patients the drug dosage had to be increased to combat the increased seizure frequency.