Background: Progestin contraception has been linked to higher risk of female to male sexual HIV transmission.
Setting: A clinical trial among HIV-infected women in Lilongwe, Malawi, randomized to initiation of depomedroxyprogesterone acetate injectable or levonorgestrel implant, and followed for up to 33 months, with the outcome of HIV shedding in the genital tract.
Methods: We compared the frequency and magnitude of HIV genital shedding before and after initiation of contraception and between study arms among women receiving antiretroviral therapy (ART). Genital HIV RNA was measured in TearFlo Strips using the Abbott RealTime HIV-1 assay.
Results: Among 68 HIV-infected Malawian women on ART, randomization to depot medroxyprogesterone acetate compared with the levonorgestrel implant was not associated with genital shedding and neither progestin contraceptive was associated with increased HIV genital shedding, for up to 33 months after contraceptive initiation. Having detectable plasma HIV [adjusted risk ratio (RR) 10.5; 95% confidence interval (CI): 3.18 to 34.7] and detectable genital shedding before contraceptive initiation (adjusted RR 3.53; 95% CI: 1.31 to 9.47) were associated with a higher risk of detectable genital shedding after contraceptive initiation. Higher plasma efavirenz concentrations were associated with a lower risk of detectable genital shedding (adjusted RR 0.85; 95% CI: 0.73 to 0.99, per increase of 1000 ng/mL).
Conclusion: Among HIV-infected women receiving ART, our results provide evidence that progestin contraception does not impact women's risk of transmission of HIV to partners. Our finding that detectable genital shedding before contraceptive initiation independently predicts shedding suggests that there may be other individual-level biological or behavioral factors that increase the risk for shedding.