Hormonal Contraception, Pregnancy, Breastfeeding, and Risk of HIV Disease Progression Among Zambian Women

BACKGROUND: Some studies suggest that hormonal contraception, pregnancy, and/or breastfeeding may influence rates of HIV disease progression. METHODS: From 1994 to 2012, HIV discordant couples recruited at couples' voluntary HIV counseling and testing centers in Lusaka were followed 3-monthly. Multivariate survival analyses explored associations between time-varying contraception, pregnancy, and breastfeeding and 2 outcomes among HIV-positive women: (1) time to death and (2) time to antiretroviral treatment (ART) initiation. RESULTS: Among 1656 female seropositive, male seronegative couples followed for 3359 person-years (PY), 224 women died [6.7/100 PY; 95% confidence interval (CI): 5.8 to 7.6]. After 2003, 290 women initiated ART (14.5/100 PY; 95% CI: 12.9 to 16.2). In a multivariate model of time to death, hormonal implant [adjusted hazard ratio (aHR) = 0.30; 95% CI: 0.10 to 0.98] and injectable (aHR = 0.59; 95% CI: 0.36 to 0.97) were significantly protective relative to nonhormonal method use, whereas oral contraceptive pill (OCP) use was not (aHR = 1.08; 95% CI: 0.74 to 1.57) controlling for baseline HIV disease stage, time-varying pregnancy, time-varying breastfeeding, and year of enrollment. In a multivariate model of time-to-ART initiation, implant was significantly protective (aHR = 0.54; 95% CI: 0.31 to 0.95), whereas OCP (aHR = 0.70; 95% CI: 0.44 to 1.10) and injectable (aHR = 0.85; 95% CI: 0.55 to 1.32) were not relative to nonhormonal method use controlling for variables above, woman's age, and literacy. Pregnancy was not significantly associated with death (aHR = 1.07; 95% CI: 0.68 to 1.66) or ART initiation (aHR = 1.24; 95% CI: 0.83 to 1.86), whereas breastfeeding was protective for death (aHR = 0.34; 95% CI: 0.19 to 0.62) and ART initiation (aHR = 0.49; 95% CI: 0.29 to 0.85). CONCLUSIONS: Hormonal implants and injectables significantly predicted lower mortality; implants were protective for ART initiation. OCPs and pregnancy were not associated with death or ART initiation, whereas breastfeeding was protective for both. Findings from this 18-year cohort study suggest that (1) HIV-positive women desiring pregnancy can be counseled to do so and breastfeed and (2) all effective contraceptive methods, including injectables and implants, should be promoted to prevent unintended pregnancy.