Lack of Folic Acid Causes Defects

BOSTON (AP) â€” Drugs that interfere with the body's use of folic acid can increase the risk of a variety of birth defects if taken during pregnancy, a study found. <br><br>Researchers agree that lack

Thursday, November 30th 2000, 12:00 am

By: News On 6

BOSTON (AP) â€” Drugs that interfere with the body's use of folic acid can increase the risk of a variety of birth defects if taken during pregnancy, a study found.

Researchers agree that lack of folic acid during pregnancy raises the risk of spina bifida and other neural tube defects. However, the suspected link with some other birth defects is less clear.

To study this, doctors checked to see if the risk of these defects increases if mothers take medicines known to disrupt the body's breakdown and absorption of folic acid.

Researchers from Boston University's Sloan Epidemiology Unit reviewed 6,932 infants born with oral clefts or defects of the heart or urinary tract. They were compared with 8,387 babies with other defects not thought to be caused by lack of folic acid.

Most drugs that can disrupt folic acid are known as dihydrofolate reductase inhibitors. They include the cancer drugs aminopterin and methotrexate; sulfasalazine, an anti-inflammatory drug; pyrimethamine, used to treat protozoal infections; triamterene, a diuretic; and trimethoprim, an ingredient of the antibiotic Bactrim.

Some drugs used to treat epilepsy, including phenytoin, phenobarbital, primidone and carbamazepine, can also can affect folic acid.

The researchers found that the risk of heart defects and oral clefts roughly tripled if mothers used dihydrofolate reductase inhibitors during the first three months of pregnancy. It doubled if they used the epilepsy medicines.

Women of childbearing age are urged to take multivitamins to make sure they get enough folic acid. The study found that the vitamins reduced much of the extra risk of birth defects among women using the dihydrofolate reductase inhibitors but not among those taking the epilepsy medicines.

The study was directed by Dr. Sonia Hernandez-Diaz and published in Thursday's New England Journal of Medicine. It was financed by the Harvard School of Public Health and several government agencies and drug companies.