Drug use during pregnancy and lactation.

This article reviews the basic principles of pharmacology and teratogenicity of drugs for the pregnant and lactating woman and summarizes the Food and Drug Administration, American College of Obstetrics and Gynecology, and American Academy of Pediatrics classifications. These categories were devised for caregivers of both women and their babies. The authors propose a two/three letter category system to assist those who, like family physicians, must care for women while pregnant and while lactating. Common problems from everyday practice are reviewed, with an emphasis on the important drugs to use and avoid in a wide variety of everyday clinical settings to help the busy primary care physician in making decisions about medications in pregnancy and lactation.