Late may be far better than never when it comes to using AZT to prevent transmission of HIV from mothers to babies. New York researchers report that giving AZT to babies within the first 48 hours of life lowered the transmission rate from the 26.6 percent seen with no treatment to only 9.3 percent, even though the mothers had not taken the drug during pregnancy. When mothers were given the drug during delivery, only 10 percent of the babies became infected. Waiting to start treatment in the babies until day three or later was much less effective, yielding a transmission risk of 18.4 percent. The best results—a transmission rate of only 6.1 percent—were seen when AZT was given to mothers during their pregnancies. The researchers urged efforts to identify all women who did not receive AZT during their pregnancies, so that the med could be given to them during delivery, and to their babies very soon after birth.