Risk of HIV infection in oral contraceptive pill users: a meta-analysis.

To review the literature and present a summary estimate of the association between HIV-1 acquisition or HIV-1 serostatus and oral contraceptives. MEDLINE database (January 1986-October 1997), AIDSLINE database (January 1980-October 1997), bibliographies of identified articles, and experts in the field of heterosexual HIV transmission. In all, 591 articles were examined. Twenty-eight studies provided adequate data to calculate a risk estimate for the association of HIV-1 serostatus or HIV-1 seroconversion with oral contraceptives and were selected for inclusion. The overall summary odds ratio (OR) for the association between seroprevalent or seroincident HIV-1 infection and use of oral contraceptives in the 28 studies was 1.19 (95% confidence interval [CI], 0.99-1.42). The summary OR for 21 cross-sectional studies was 1.21 (95% CI, 1.01-1.44), whereas the summary relative risk for seven prospective studies was 1.32 (95% CI, 1.12-1.57). Study quality was assessed by applying a scale reflecting study design, measurement of exposure, ability to assess confounding, and publication status. The summary OR for the eight best studies was 1.60 (95% CI, 1.05-2.44). When analysis was limited to studies conducted in Africa, the summary OR was 1.45 (95% CI, 1.15-1.83) for the 14 studies overall, and 1.65 (95% CI, 1.09-2.52) for the seven best studies. This meta-analysis found a significant association between oral contraceptive use and HIV-1 seroprevalence or seroincidence. For women at risk of HIV-1 infection, oral contraceptive use for prevention of pregnancy should be accompanied by condom use for prevention of HIV-1 infection.