Hormonal contraception and the risk of HIV acquisition.

BACKGROUND: Combined oral contraceptives (COC) and depot-medroxyprogesterone acetate (DMPA) are among the most widely used family planning methods; their effect on HIV acquisition is not known. OBJECTIVE: To evaluate the effect of COC and DMPA on HIV acquisition and any modifying effects of other sexually transmitted infections. METHODS: This multicenter prospective cohort study enroled 6109 HIV-uninfected women, aged 18-35 years, from family planning clinics in Uganda, Zimbabwe and Thailand. Participants received HIV testing quarterly for 15-24 months. The risk of HIV acquisition with different contraceptive methods was assessed (excluding Thailand, where there were few HIV cases). RESULTS: HIV infection occurred in 213 African participants (2.8/100 woman-years). Use of neither COC [hazard ratio (HR), 0.99; 95% confidence interval (CI), 0.69-1.42] nor DMPA (HR, 1.25; 95% CI, 0.89-1.78) was associated with risk of HIV acquisition overall, including among participants with cervical or vaginal infections. While absolute risk of HIV acquisition was higher among participants who were seropositive for herpes simplex virus 2 (HSV-2) than in those seronegative at enrolment, among the HSV-2-seronegative participants, both COC (HR, 2.85; 95% CI, 1.39-5.82) and DMPA (HR, 3.97; 95% CI, 1.98-8.00) users had an increased risk of HIV acquisition compared with the non-hormonal group. CONCLUSIONS: No association was found between hormonal contraceptive use and HIV acquisition overall. This is reassuring for women needing effective contraception in settings of high HIV prevalence. However, hormonal contraceptive users who were HSV-2 seronegative had an increased risk of HIV acquisition. Additional research is needed to confirm and explain this finding.

Acceptability of five nonoxynol-9 spermicides.

OBJECTIVE: To examine the acceptability of five nonoxynol-9 (N-9) spermicides. METHODS: We analyzed data from a randomized trial of five products, including three gels containing different amounts of N-9 per dose, a film and a suppository. In the trial, 1536 participants were asked to use the assigned spermicide for 7 months and to complete questionnaires 4 weeks after admission and at discontinuation. RESULTS: Overall, 43% of participants liked their spermicide "very much." This proportion was higher in the three gel groups than in the suppository and film groups. Difficulty with insertion, messiness and discontent with timing of insertion were common complaints in all groups. After adjustment for selected baseline factors, acceptability on the first questionnaire was not related to duration or consistency of subsequent spermicide use or to subsequent time to pregnancy. CONCLUSIONS: In this study, all five spermicides were considered acceptable by most users. Acceptability did not appear to influence spermicide use or pregnancy risk.

Participant characteristics associated with withdrawal from a large randomized trial of spermicide effectiveness.

BACKGROUND: In most recent large efficacy trials of barrier contraceptive methods, a high proportion of participants withdrew before the intended end of follow-up. The objective of this analysis was to explore characteristics of participants who failed to complete seven months of planned participation in a trial of spermicide efficacy. METHODS: Trial participants were expected to use the assigned spermicide for contraception for 7 months or until pregnancy occurred. In bivariable and multivariable analyses, we assessed the associations between failure to complete the trial and 17 pre-specified baseline characteristics. In addition, among women who participated for at least 6 weeks, we evaluated the relationships between failure to complete, various features of their first 6 weeks of experience with the spermicide, and characteristics of the study centers and population. RESULTS: Of the 1514 participants in this analysis, 635 (42%) failed to complete the study for reasons other than pregnancy. Women were significantly less likely to complete if they were younger or unmarried, had intercourse at least 8 times per month, or were enrolled at a university center or at a center that enrolled fewer than 4 participants per month. Noncompliance with study procedures in the first 6 weeks was also associated with subsequent early withdrawal, but dissatisfaction with the spermicide was not. However, many participants without these risk factors withdrew early. CONCLUSIONS: Failure to complete is a major problem in barrier method trials that seriously compromises the interpretation of results. Targeting retention efforts at women at high risk for early withdrawal is not likely to address the problem sufficiently.

Contraceptive effectiveness and safety of five nonoxynol-9 spermicides: a randomized trial.

OBJECTIVES: To estimate and compare the effectiveness and safety of 5 spermicides over 6 and 7 months of use, respectively. The spermicides included 3 gels containing 52.5 mg, 100 mg, and 150 mg of nonoxynol-9 per dose and a film and a suppository, each containing 100 mg of nonoxynol-9 per dose. METHODS: Women wishing to use only spermicide for contraception for 7 months were randomly assigned to use 1 of the 5 spermicides with emergency contraception backup. Participants were followed up for up to 30 weeks after admission. RESULTS: Of 1,536 women enrolled, 868 (57%) either relied on the spermicide for 6 months or became pregnant. The probability of pregnancy during 6 months of typical use of the spermicide was 22% (95% confidence limits 16%, 28%) in the 52.5-mg gel group, 16% (10%, 21%) in the 100-mg gel group, 14% (9%, 19%) in the 150-mg gel group, 12% (7%, 17%) in the film group, and 10% (6%, 15%) in the suppository group. The pregnancy risk in the 52.5-mg gel group was significantly different (P <.05) from that in either of the other gel groups. The pregnancy risks in the three 100-mg product groups were not significantly different (P =.35). No significant differences among groups were found in the 7-month probability of specified urogenital conditions. CONCLUSION: The gel with the lowest amount of nonoxynol-9 was less effective than the 2 higher-dose gels. Among 3 products containing 100 mg of nonoxynol-9, formulation did not significantly affect pregnancy risk. All products were safe. LEVEL OF EVIDENCE: I