(HealthDay News) -- American women of childbearing age commonly take prescription drugs that can cause birth defects, but only about half are receiving contraceptive counseling from their doctors or other health care providers, a new study finds.
Researchers at the University of Pittsburgh School of Medicine are calling for increased awareness of this issue among doctors and women who may become pregnant.
"We found that over the course of a year, one in six women of reproductive age filled a prescription for a medication labeled by the Food and Drug Administration as increasing risk of fetal abnormalities," first study author Dr. Eleanor Bimla Schwarz, assistant professor in the departments of medicine and obstetrics, gynecology and reproductive medicine, said in a prepared statement.
"Unfortunately, many women filling prescriptions that can increase the risk of birth defects remain at risk of pregnancy," Schwarz said.
The study involved an analysis of all prescriptions filled by more than 488,000 reproductive-aged women enrolled in a large managed health care plan during 2001.
The researchers also examined the use of contraception and pregnancy test results.
They found little difference in rates of contraceptive counseling, use of contraception or subsequent pregnancy test results when women took medications that increase the risk of birth defects versus safer medications.
About half of pregnancies in the United States are unintended, according to background information in the study, which was published in the Sept. 18 issue of the journal Annals of Internal Medicine.
"While efforts are needed to ensure that women get information about birth control and the risk of medication-related birth defects, it also is important to realize that different birth control methods are not equally effective," Schwartz noted. "Women who were using the most effective methods of contraception, such as the intrauterine device or IUD, were least likely to have a positive pregnancy test after filling a prescription for a potentially dangerous medication."
The March of Dimes outlines drugs and herbs that pregnant women should avoid.