(USA TODAY) -- New guidelines out today provide some reassurance for the approximately half a million U.S. women of childbearing age who have epilepsy.

About three to five of every 1,000 births in the USA are to women with epilepsy. The guidelines, developed by the American Academy of Neurology and the American Epilepsy Society and published in the journal Neurology, show that pregnancy is relatively safe for such women as long as they take certain precautions if possible. Among them:

*Avoid taking valproate (also called valproic acid). Research has linked the drug to a higher risk of serious fetal malformations and decreased thinking ability compared with other anti-epileptic drugs.

*Avoid taking more than one anti-epileptic drug.

*Avoid taking phenytoin and phenobarbital, which also have been linked to decreased thinking ability in offspring.

*Stop smoking. For reasons that aren't clear, pregnant women with epilepsy who smoke appear to have a substantially increased risk of premature contractions and preterm delivery.

Doctors emphasize that uncontrolled seizures are riskier than any anti-epileptic drug.

"The decision about which drug to use is something that should be made with the input of the neurologist," says lead author Cynthia Harden of the University of Miami. "One of the difficulties that we face is sometimes there are seizure disorders that respond really well to valproate and not the other medications."

But Harden says, "Most of us working in epilepsy have found there are reasonable alternatives."

Says Mary Katherine Albritton, 29, an Atlanta woman with epilepsy who has two healthy children: "It really breaks my heart to hear that women who are epileptic shy away from having children. It can be done."

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