A Trial of Shortened Zidovudine Regimens to Prevent Mother-To-Child Transmission of Human Immunodeficiency Virus Type 1 [Lallemant M, et al. NEJM 2000;343:982]: This is a study conducted by the Perinatal HIV Prevention Trial (Thailand) Investigators who examined four AZT regimens with variations on the duration of treatment in the mother and variations in duration of treatment in the infant. One group received therapy beginning at 28 weeks gestation with treatment to the infant for six weeks (long-long), a second received treatment at 35 weeks gestation and the newborn was treated for three days (short-short), the third group was short-long, and the fourth was long-short. There were 1,437 women enrolled, but the study was stopped when the perinatal transmission rate in the group that received long-long therapy was significantly better than the transmission rate in the short-short group with rates of 4.1% and 10.5%, respectively (p = 0.004). The other two regimens did not differ statistically, but longer treatment in the mother was advocated to reduce in utero transmission. posted 10/11/2000