Pregnant women often maintain sexual activity, and research has shown that they may have a greater risk of acquiring HIV infection during pregnancy. Preliminary research has suggested that tenofovir 1% gel, a vaginal microbicide, may reduce the risk of HIV infection for women when it is applied at the time of sexual intercourse. However, safety data on the use of tenofovir 1% gel during pregnancy are limited. This study will enroll pregnant women who will use tenofovir 1% gel on a daily basis for 28 consecutive days during their pregnancy, which is a longer period of use than has been studied previously. The purpose of this study is to evaluate the safety of 1% tenofovir gel in HIV-uninfected pregnant women when used during the late first trimester and second trimester of pregnancy.~Participants will be healthy, HIV-uninfected pregnant women and will be randomly assigned to use either 1% tenofovir gel or placebo gel once a day for 28 days or until delivery, whichever comes first. Participants will be further divided into four groups of varying gestational age ranges. These groups will be filled sequentially, starting with the later gestational ages (closer to the time of delivery) group first. Once the safety for this group is confirmed, groups of participants with earlier gestational ages will be enrolled.~Length of participation in this study will vary depending on gestational age at the time of enrollment, but each participant will have visits at study entry; Days 7, 14, and 28; 2 weeks after the last dose of the assigned gel; and once every 4 weeks until delivery. Participants who have used the gel within 24 hours of arriving at the hospital for delivery also will have a delivery visit. At most visits, participants will give a medical history; undergo blood and urine collection; and have a physical exam, including obstetric (OB) abdominal and pelvic exams. Participants also will report adverse events and complete an adherence assessment. If a participant has a delivery visit, blood will be collected from the umbilical cord and delivery and infant information will be collected. All participants will attend a follow-up study visit 30 days after delivery.
Preliminary research has shown that a vaginal gel containing the antiretroviral (ARV) drug tenofovir may reduce the risk of HIV infection in women when used near the time of sexual intercourse. This study will evaluate the safety of 1% tenofovir gel in HIV-uninfected pregnant women and their newborns when the gel is used once a day for a period of 28 days at a designated time during pregnancy.