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Phenobarbital Linked to Lower IQ

Subject: Lower IQ Linked To Drug
Organization: Copyright 1995 by The Associated Press
Date: Tue, 14 Nov 1995 15:50:29 PST

IQ scores were even lower if the men whose mothers took the drug also came from poor families or were the product of unwanted pregnancies, said June Machover Reinisch, a senior research fellow at the Kinsey Institute for Research in Sex, Gender and Reproduction at Indiana University in Bloomington. The study suggests that doctors should be careful about prescribing phenobarbital during pregnancy and that a supportive, healthy environment can go a long way toward making up for biological disadvantages, she said.

``We have to be very careful about anything we do during pregnancy,'' said Reinisch. ``There are risks with everything. You have to balance the benefits with the risks.''

Reinisch estimates 23 million Americans who are now adults were exposed to phenobarbital in the womb. The drug was formerly prescribed as a sleeping aid, tranquilizer, treatment for pregnancy-related high blood pressure and pregnancy-related vomiting and other reasons, she said.

The barbiturate is prescribed much less now than it was in the 1960s, '70s and early '80s, but among pregnant women, it is still an important treatment for seizure disorders such as epilepsy, which are estimated to afflict one in every 200 Americans.

Most mothers in the study, published in Wednesday's issue of The Journal of the American Medical Association, took the drug for pregnancy-related high blood pressure.

Two experts urged caution at interpreting the findings, saying other factors than the drug may have affected the men's intelligence in ways the study couldn't detect.

Dr. John Larsen, a professor of obstetrics, gynecology and genetics at George Washington University, said pregnant women who are taking phenobarbital under a doctor's supervision shouldn't suddenly stop without consulting their doctors.

``That could create immediate harm, which would be women having a seizure,'' he said.

Dr. Karen Filkins, director of reproductive genetics at The Western Pennsylvania Hospital in Pittsburgh, said that among drugs for seizure-related disorders, phenobarbital is probably the safest. Other drugs may cause birth defects in babies, she said.

In the study, two different intelligence tests were given to two different groups of Danish men born between 1959 and 1961. One group had 33 men and the other group, 81.

Men who were exposed to phenobarbital in the womb on average had seven points less intelligence on a 100-point scale than similar men who weren't exposed.

If men exposed to the drug came from poor families, they had a 12.5-point disadvantage. And exposed men who both came from poor families and were born to mothers who hadn't wanted to be pregnant fared 20 points worse.

The worst intelligence scores among exposed men were only slightly below average.

The researchers chose Denmark because it has a national health registry going back decades that shows what mothers took during pregnancy. It also permits tracking people over their lifetimes, unlike U.S. data, Reinisch said.