Pre-exposure Prophylaxis for HIV-1 Prevention Does Not Diminish the Pregnancy Prevention Effectiveness of Hormonal Contraception

Pamela M. Murnane; Renee Heffron; Allan Ronald; Elizabeth A. Bukusi; Deborah Donnell; Nelly R. Mugob; Edwin Were; Andrew Mujugira; James Kiarie; Connie Celum; Jared M. Baeten

Disclosures

AIDS. 2014;28(12):1825-1830. 

In This Article

Results

Among the 1785 HIV-1-uninfected women enrolled in the Partners PrEP study, the median age was 33 years [interquartile range (IQR) 28–38] and median partnership duration with their HIV-1-infected partner was 12 years (IQR 6–18) (Table 1). Women reported an average of 3 (IQR 1–5) children with their study partner, with 15% having no children. Curable sexually transmitted infections were identified in 10%, and unprotected sex in the past month was reported by 23%.

Approximately half of the study population reported contraceptive use at enrollment, with injectable hormones the most common method reported (27% of all women). During follow-up, 14% of women initiated oral pills, 20% initiated injectable hormones, and 6% received implants. In total, hormonal contraceptives were used during 51% of all nonpregnant follow-up time: oral contraceptives 11%, injectables 31%, and implants 8%. No contraception was reported during 35% of nonpregnant follow-up time and other forms of contraception were reported for the remaining 14%.

A total of 288 pregnancies were observed in 267 women (179 assigned PrEP and 88 assigned placebo). Pregnancy incidence and outcomes did not differ across study arms.[11] Among women reporting no contraceptive use, pregnancy incidence was 15.4% per year: 14.6 and 17.4% for women assigned PrEP and placebo, respectively (Table 2). Women reporting oral contraceptive use had similar pregnancy incidence compared to women reporting no contraception; oral contraceptive effectiveness did not differ significantly for women assigned PrEP [adjusted hazard ratio (aHR) 0.96] compared to placebo (aHR 0.55, P-value for difference in aHRs = 0.24). Women reporting injectable contraception had 75–80% reduction in pregnancy incidence compared to women not using contraception, and this did not differ by randomization arm (PrEP: aHR 0.26, P < 0.001; placebo: aHR 0.19, P < 0.001; P-value for difference = 0.47). Further, effectiveness during the first 3 months after injectable contraception initiation and after longer duration use did not differ by randomization arm (data not shown). Implantable contraception was highly effective for pregnancy prevention (incidence <1% per year) in both PrEP and placebo arms. In sensitivity analyses, excluding follow-up time when the PrEP study drug was withheld and when adherence to PrEP/placebo was estimated to be poor (16% of nonpregnant follow-up time), the results for all contraceptive methods were essentially the same (data not shown).

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