SPINA-BIFIDA AND CLEFT-LIP AMONG NEWBORNS OF NORWEGIAN WOMEN WITH EPILEPSY - CHANGES RELATED TO THE USE OF ANTICONVULSANTS

Objectives. This study examined the connection between the use of anti convulsants for epilepsy during or before pregnancy and the risk of sp ina bifida and cleft lip in newborns. Methods. Among mothers registere d from 1967 to 1992 by the Medical Birth Registry of Norway, 7588 who had epilepsy were identified and their newborns' prevalence of spina b ifida and cleft lip examined. Results. The odds ratio of spina bifida in children of mothers with epilepsy compared with other children incr eased from 1.5 in 1967 through 1980 (95% confidence interval [CI] = 0. 3, 4.5) to 4.4 in 1981 through 1992 (95% CI = 2.0, 8.5), The odds rati o of cleft lip, however, decreased from 3.0 before 1981 (95% CI = 1.6, 5.1) to 1.1 after 1981 (95% CI = 0.4, 2.3). Conclusions, This shift t oward more serious birth defects is consistent with the different tera togenic effects of newer and older anticonvulsants.