Medications can block folic acid

BEER-SHEVA, Israel, Oct. 16 (UPI) -- Israeli doctors warn medications can block the action of folic acid during pregnancy.

Pregnant women are advised to take folic acid as part of prenatal care to prevent abnormalities in the baby.

"After studying the data, we concluded that first trimester exposure to folic acid antagonists is associated with increased risk for neural tube, cardiovascular and urinary tract defects," principal investigator Dr. Rafael Gorodischer of Ben-Gurion University of the Negev says in a statement.

The study, published in the Journal of Clinical Pharmacology, finds two groups of medications can affect how folic acid works in the body.

The first group either prevents folic acid from working or prevents folate from being converted into its active metabolites -- such as the antibiotic trimethoprim, a drug to treat ulcerative colitis called sulfasalazine and a chemotherapy drug, methotrexate.

The second group includes medications that lower serum and tissue concentrations of folate by various mechanisms. This group includes some anti-epileptics and cholesterol-lowering drugs.

"The study shows that exposure to folic acid antagonists in the first trimester of pregnancy more than doubles the risk of congenital malformations in the fetus and that neural tube defects, such as spina bifida and malformations of the brain, increase by more than six-fold after exposure to these antagonists," said Dr. Amalia Levy, an epidemiologist at Ben Gurion University.