The correlation of deficits in IQ with midface and digit hypoplasia in children exposed in utero to anticonvulsant drugs

Abstract

Children exposed during pregnancy to the anticonvulsant drugs phenytoin, phenobarbital, and carbamazepine as monotherapy and polytherapy have an increased frequency of midface and digit hypoplasia. Some children also have cognitive dysfunction. The hypothesis tested is that the anticonvulsant drug-exposed child with midface and digit hypoplasia is more likely to have cognitive dysfunction. Children exposed to anticonvulsant drugs (n = 80) were recruited for a follow-up evaluation, which included testing cognitive function and a physical examination for head size, height, and the presence of midface and digit hypoplasia. Microcephaly, midface and digit hypoplasia, and major malformations were correlated with full scale (FSI), performance (PIQ) and verbal (VIQ) intelligence. The presence of the 3 anticonvulsant-exposed children with microcephaly had a deficit of 23.7 IQ points in FSI in comparison with the other children with a normal head size. Either midface or digit hypoplasia, after excluding the persons with microcephaly and with the Bonferroni correction, correlated significantly with deficits in VIQ (-12.7), PIQ (-10) and FSI (-12.8) IQ points ( P = .0061). There was no decrease in IQ in association with major malformations. The presence of midface and digit hypoplasia in a child exposed to anticonvulsant drugs in pregnancy is an indication for a systematic developmental evaluation.