According to a new study reported in this month's issue of Sexually Transmitted Infections, women who take HIV drug combinations during their first trimester may increase their risk of bearing children with birth defects. Dr. Graham Taylor of Imperial College in London studied 195 HIV-infected mothers. Dr. Taylor found that women who took a drug to prevent Pneumocystis carinii pneumonia (PCP), a potentially fatal condition common in AIDS patients, along with antiretroviral drugs, were more likely to deliver a baby with a birth defect. Over twenty percent of newborns exposed to both drugs suffered abnormalities. Taking the drugs independently did not appear to increase a woman's risk.