Over 16 million reproductive age women are HIV+ . Access to ARVs for HIV treatment is expanding, and like the HIV epidemic more than half of all ARV users are women . The fusion of contraceptives to antiretrovirals (ARV’s) for HIV treatment and Pre-Exposure Prophylaxis (PrEP) is on the horizon, because similar to ARVs, effective contraception, such as combined oral contraceptives (COCs), saves lives and lowers the burden of HIV on individuals and society . The COC is the second most popular contraceptive worldwide, is inexpensive, and easy to store and dispense . However, HIV+ women on common ARV regimens are advised to avoid COCs by guidelines and monographs [5–7]. Decreased serum concentrations of contraceptive steroids are reported when ARVs such as nevirapine and lopinavir/ritonavir (LPV/r) are taken concomitantly [8–11]. However, whether the decrease in steroid concentration truly results in failure of COC effectiveness is unknown because data on clinical outcomes such as pregnancy or ovulation are limited [12–13].
Understanding interactions between ARV and oral contraceptives has recently become an even more urgent matter for research. First, the preliminary reported results from FEM PrEP (Study to Assess the Role of Truvada® in Preventing HIV Acquisition in Women) indicate that women taking oral contraceptives and a daily fixed dose tenofovir/emtricitabine combination had the highest proportion of pregnancies (9%) . Although investigations are ongoing to understand the basis for this finding, there are no data describing the effect of these drugs on ovulation in women taking oral contraceptives. Second, the promising findings from HPTN 052 (Preventing Sexual Transmission of HIV with Anti-HIV Drugs)  highlight the need to ensure HIV+ women on antiretrovirals have equal opportunities for fertility control. The objective of our study was to assess the feasibility of measuring anovulation in a PK study of COCs and ARVs in women in Malawi.