Researchers at the University of Pittsburgh will commence a clinical trial on a vaginal microbicide in pregnant women. Sixteen HIV-negative women, scheduled for caesarean delivery at the University’s Women’s Hospital, will be enrolled in coming months and given a single dose of tenofovir topical gel applied inside the vagina two hours before giving birth. Researchers hope to understand the extent that pregnancy affects how the body absorbs the active drug in the gel and whether the drug can be transferred to the foetus.

Tenofovir is an effective drug used to treat HIV and researchers wish to know if it could work as a microbicide in the future. The risk of participants in a microbicide trial becoming pregnant has always been of concern to researchers even though trial protocols require the use of contraception. Indeed pregnancy has occurred in 5- 10% of participants. Because the risks to the women and their babies are unknown, they are told to stop using the product immediately.

With this trial researchers hope to learn more about the use and safety of microbicides during pregnancy. Using information from other trials where women have become pregnant while on either a microbicide or an oral antiretroviral drug they are also looking to discover whether using these during pregnancy — a time when women are at even greater risk of acquiring HIV through sexual intercourse — could prevent mother-to-child transmission and if there are any effects on foetal and/or neonatal development.