Researchers from Australia have found that reducing the dose of valproate, anti-epilepsy drug, during pregnancy can reduce the risk of the baby having a birth-defect.

Previous studies have shown that exposure to antiepileptic drugs in the womb can lead to development of autism and other neurological disorders. Apart from migraine headache, valproate is also used to relieve symptoms of epilepsy (seizure). The U.S. Food and Drug Administration recently warned mothers-to-be against using valproate for migraines.

Now, researchers from Royal Melbourne Hospital found that higher doses of the drug can raise the risk of developmental disorders in children. The research can help women on these medications who are planning to start a family reduce the risk of birth defects in children.

Data for the study came from the Australian Pregnancy Register (APR), which has data on about 1700 women diagnosed with epilepsy who were or are pregnant.

"For many women on epilepsy medication, the desire to start a family can be fraught with fear that they could have a baby with a range of disabilities or malformations," said Professor Terry O'Brien, epilepsy specialist at the Royal Melbourne Hospital.

"Previous studies have shown a strong relationship between the dose of valproate taken and the risk of the child having a birth defect. However, for many women valproate is the only drug that will help control their seizures," Professor O'Brien said in a news release. "Through our research, we now know that by reducing the dose taken in the first trimester of pregnancy, the risk of having a baby with spina bifida or hypospadias will be greatly reduced."

Spina bifida is an incurable birth defect of spine and spinal cord whereas Hypospadias is a birth defect of the penis and can be cured with a surgery.

Researchers found that certain birth defects such as cleft palates and heart defects were common in children whose mothers took valproate during pregnancy.

The study is published in the journal Neurology.