Recently, the U.S. Food and Drug Administration said it took steps to close a loophole in the iPledge program by warning women not to buy Accutane, or any generic forms of the drug, over the Internet, to bypass the monitoring program. But a report found 122 pregnancies were exposed during the first year of the iPledge program.

Isotretinoin, one of the most potent teratogens, is marketed under several brand names to treat severe acne that doesn't respond to conventional treatments. It is chemically related to vitamin A. Birth defects associated with isotretinoin include mental retardation, brain and heart defects.

Birth defects or miscarriages can occur soon after conception, often before a woman realizes she is pregnant.

"It's certainly a positive step that FDA and the drug manufacturers have made this information publicly available, so that the iPledge program can be properly evaluated," Dr. Michael Katz, senior vice president for research and global programs of the March of Dimes, said in a statement.