LA Times,"Birth defect-antidepressant, including Paxil, link found"

         Infants born to women taking commonly prescribed antidepressants during the first trimester of their pregnancies have an increased risk of serious birth defects, though the danger remains tiny, according to two studies published today.   

The reports in the New England Journal of Medicine found a higher risk of developmental problems affecting the intestines, brain and skull. Although life-threatening, all of the defects are rare and normally occur in no more than one in 2,500 births.

Others studies have linked a mother's antidepressant use later in pregnancy to an increased risk of lung problemsin newborns. Two reports have tied the drug Paxil, in particular, to a higher rate of congenital heart malformation. The drug carries a warning about heart defects.

         The studies focused on antidepressants known as selective serotonin reuptake inhibitors, a class that includes Paxil, Prozac, Zoloft and Celexa. The medications work by enhancing the activity of the brain chemical serotonin. They have become the standard treatment for depression since their introduction in the 1980s        

In addition to acting on the brain to improve mood, serotonin constricts blood vessels and performs other functions. The full impact of manipulating serotonin levels within the body isn't completely understood, although animal studies have detected a role for serotonin in prenatal development of the heart and head.

        Taken together, the two studies looked at 19,471 infants with birth defects and compared them with 9,952 normal babies. Researchers examined which antidepressants mothers had taken during the first trimester and searched for patterns among dozens of different birth defects reported.

        The studies found that Paxil tripled the risk of a heart defect that reduces blood flow to the lungs, though the chance of developing such a defect was less than 1%, according to an editorial published with the reports. No other antidepressants were linked to cardiac problems.