Drops in use of valproate linked to fewer Australian birth defects.(Obstetrics)

WASHINGTON -- Decreased use of valproate to manage epilepsy during pregnancy in Australia has produced a corresponding drop in fetal malformations associated with the drug, Dr. Frank Vajda said at the joint annual meeting of the American Epilepsy Society and the American Clinical Neurophysiology Society.

Dr. Vajda, a neurologist at the Victorian Epilepsy Centre in Victoria, Australia, presented the most recent data from the Australian Pregnancy Registry for Women on Antiepileptic Medication. The registry, established in 1999, has enrolled 810 women--77% of all Australian women who had taken antiepilepsy drugs (AEDs) for any reason. The 64-month data contained outcome information on 715 births.

Of the women in the registry, most who were currently taking AEDs (692) were taking the drugs for epilepsy. Other indications were bipolar disorder (11), pain (4), sleep (1), and unspecified (14). The majority of the women (504) were on AED monotherapy.

Most of the births (640) were of live infants without congenital malformations. There were 44 births with fetal malformations: 27 live births with defects, 9 live births with defects that emerged by 1 year, and 8 induced abortions of malformed fetuses. The malformations included spina bifida, anencephaly, holoprosencephaly, Dandy-Walker syndrome, and a variety of cardiac defects.

There were also 23 spontaneous abortions, one induced abortion for maternal indications, and seven stillbirths; no malformations were noted in these fetuses.

The only significant drug/defect associations occurred in women taking high doses of valproate, either as monotherapy or polytherapy. Women taking more than 1,100 mg/day ...