Mom's Epilepsy Meds May Alter Infant Head Shape

NEW YORK (Reuters Health) - Women who use anticonvulsants during pregnancy may increase the risk of delivering an infant with a rare condition called craniostenosis, a study hints.

The skull consists of five thin, curved, bony plates that meet along lines called sutures. At birth, the bony plates of the skull are not completely joined along the sutures. This allows the baby's head and brain to grow and develop after birth. After age 2, the sutures begin to close so that the bones can join or fuse together.

Craniostenosis is a condition in which the skull sutures close and the bony plates of the skull become fused too early in life, resulting in an abnormal head shape. It is estimated to occur in about one in every 2,500 births. Craniostenosis usually develops while the fetus is still in the mother's womb and often is evident at birth or soon after.

Previous reports have suggested an association of craniostenosis with certain drugs or with maternal treatment for fertility problems but the associations remain controversial.

To investigate, Dr. Bengt Kallen from University of Lund in Sweden and others used data from the Swedish Medical Birth Registry and from the Central-East French Registry to study the epidemiology of craniostenosis, with special emphasis on maternal drug use and fertility problems.

There was a clear-cut and significant increase in the risk of craniostenosis after exposure to anticonvulsants, the investigators report in the November issue of the Cleft Palate-Craniofacial Journal.

Exposure to anticonvulsants conferred a sevenfold increase in risk, the results indicate, with the greatest association seen with valproic acid.

There was also a trend towards an increased risk of craniostenosis among women who took antidepressants during the first trimester, the report indicates.

There was no increased risk for craniostenosis among women treated for infertility, the researchers note.

SOURCE: Cleft Palate-Craniofacial Journal, November 2005.