This session highlighted the controversy that remains around the role of hormonal contraception in HIV acquisition, transmission and disease progression, and the need for stronger evidence to determine whether harm exists. The importance of expanding the range of contraceptive options for women in high risk settings was emphasised.

 Further analysis of data from an African sero-discordant couple cohort confirmed initial findings by Heffron and colleagues that hormonal contraception increased the risk of HIV acquisition two-fold. Adjustments for coital frequency, and reporting of unprotected sex by the women or her male partner, did not alter these results. Reducing misclassification by controlling for contraceptive switching, and attempting to isolate the effect of DMPA by excluding non-DMPA users also did not alter this outcome substantially.

 A systematic review of 8 studies evaluated the evidence for hormonal contraception as a risk for HIV acquisition. Of the studies reviewed, only one showed evidence of a risk between the use of oral contraceptives and HIV acquisition. Eight studies evaluating the association between injectable contraceptive use and the risk of HIV acquisition had heterogeneous results. No clear causal association could be established with the current data. Sources of confounding include condom use, lack of data on male partner HIV status and level of transmission risk in most studies, and imprecise estimates of timing of infection.

Insights into the biological plausibility of HIV acquisition associated with hormonal contraceptive use were provided in a cross-sectional study of 199 recently infected women and 633 controls matched on age and time in study. When compared to non-hormonal users, injectable contraceptive use with DMPA was associated with lower levels of the anti-inflammatory regulator IL-1RA overall and, in women with selected STI, with significantly lower odds of IL-1RA concentrations. These data suggest that hormonal contraceptives differentially modulate levels of protective immune mediators in the genital tract, altering responses to STIs and providing insights into the mechanism of HIV acquisition.

A systematic review of the effect of hormonal contraception (HC) on HIV disease progression found that despite the existence of at least one randomised controlled trial suggesting that HC enhanced HIV disease progression, the preponderance of evidence across several studies suggest that there is no evidence of excess harm in HIV positive women.

Combined these data raise questions about the potential risks associated with hormonal contraception, but need to be balanced against the risks associated with an unwanted pregnancy in the populations at risk for HIV. These data highlight the need for trials to provide definitive evidence on the causal role of hormonal contraception in HIV acquisition, and emphasise the need for expanding the range of alternative contraceptive options for women living in high HIV prevalence settings.