Most women know there are certain substances to avoid after becoming pregnant, such as caffeine, alcohol and tobacco. But not enough doctors are warning women about the danger of becoming pregnant while taking certain prescription medications.

Nearly half of women taking medicines that can be harmful to a fetus aren’t receiving any counseling about the importance of using birth control or other contraceptives, according to University of Pittsburgh Medical Center researchers.

The drugs are considered common and safe… unless a woman becomes pregnant. The researchers looked at prescriptions filled by nearly half a million women of child-bearing age enrolled in a large managed health care plan in 2001. Researchers also looked at the use of contraceptives and pregnancy test results.

Women prescribed drugs with a high risk of birth defects were no more likely to receive counseling about pregnancy prevention than women prescribed safer medications.

Even safeguards built into the law don’t always work. For example, anyone taking the acne-prevention medication Accutane is required to use birth control, pass a pregnancy test before each refill and enroll in a national registry. Despite these precautions, administrators reported one-hundred-twenty women taking the medicine became pregnant last year.

The March of Dimes has compiled a list of medications women should avoid if they wish to become pregnant. In addition to Accutane, women should also be cautious about taking certain kinds of medicines used to treat high blood pressure and psoriasis. For more information, visit the March of Dimes Web site at www.marchofdimes.com.