Pregnancy rates among female participants in phase I and phase IIA AIDS vaccine clinical trials in Kenya.

Female participants in AIDS candidate vaccine clinical trials must agree to use effective contraception to be enrolled into the studies, and for a specified period after vaccination, since the candidate vaccines' effects on the embryo or foetus are unknown.To review data on female participants' pregnancy rates from phase I and IIA AIDS vaccine clinical trials conducted at the Kenya AIDS Vaccine Initiative (KAVI) and to discuss the challenges of contraception among female participants.Descriptive observational retrospective study.KAVI clinical trial site, Kenyatta National Hospital and University of Nairobi, Kenya.Thirty nine female participants were enrolled into these trials. They received family planning counselling and were offered a choice of different contraceptive methods, as per the protocols. All contraception methods chosen by the participants were offered at the study site at no cost to the participant.Four women conceived during the study period when pregnancies were to be avoided. All four had opted for sexual abstinence as a contraceptive method, but reported having been coerced by their partners to have unprotected sexual intercourse.Abstinence is clearly not a reliable contraceptive option for women in developing-country settings. Effective female-controlled contraceptives, administered at the clinical trial site, may empower female participants to better control their fertility, leading to more complete clinical trial data.