Delivery of Antiretroviral Pre-exposure Prophylaxis for HIV prevention in Pregnant and Postpartum Women
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Women in sub-Saharan Africa have substantial risk of acquiring HIV acquisition during and soon after pregnancy. Additionally, acute HIV infection among pregnant and breastfeeding women poses a double burden in that acute maternal HIV accounts for nearly one-third of all mother-to-child transmissions of HIV (MTCT). To reach global targets for elimination of MTCT and HIV prevention for mothers, it is critical to integrate effective primary HIV prevention strategies into maternal and child health (MCH) services. Tenofovir disoproxil fumarate (TDF)-based pre-exposure prophylaxis (PrEP) prevents HIV infection in adherent women. The World Health Organization (WHO) recommends PrEP for all individuals, including pregnant and breastfeeding women, at substantial HIV risk (defined as HIV residence in regions where HIV incidence is >3%). Programmatic delivery of PrEP for pregnant women is currently being considered in high-prevalence regions, though implementation approaches that efficiently optimize the benefit of PrEP during pregnancy have not been defined. Additionally, although WHO guidelines support PrEP use in pregnancy, national committees have differed in their conclusions. For example, PrEP use during pregnancy is supported by Kenyan antiretroviral guidelines but the lack of complete safety data led PrEP to be contraindicated for pregnant women in the current South African PrEP guidelines. As countries expand programmatic delivery of PrEP to pregnant women, it is important to understand motivations and beliefs for using PrEP during pregnancy to address concerns unique to this population. The studies within this dissertation address the implementation science gaps described above for the delivery of PrEP for HIV prevention to pregnant and postpartum in sub-Saharan Africa. To inform efficient PrEP delivery models, we present an empiric risk score for identifying pregnant and postpartum Kenyan women at highest risk for HIV acquisition who would mostly benefit from PrEP while reducing unnecessary exposure among low-risk women. Using data that could be easily collected in standard MCH clinic settings without additional laboratory diagnostics, our risk score identified 56% of pregnant women who acquired HIV among just 16% of women. Using register data from 62 antenatal MCH facilities throughout Kenya, we further estimated the absolute number and proportion of HIV-uninfected pregnant women in Kenya who could be offered PrEP under different public health approaches, including offering PrEP universally or based on either regional HIV prevalence and/or individual-level HIV risk factors. We found that offering PrEP only to pregnant women in the region with highest HIV prevalence (Nyanza) would reduce PrEP use among low-risk women by 74%, but exclude 63% of women with high risk for HIV based on individual-level characteristics nationally. To complement service delivery data, we also assessed experiences of using PrEP during pregnancy among HIV-uninfected Kenyan women in HIV-serodiscordant couples who became pregnant while using PrEP. The personal experiences of women with direct exposure to PrEP during pregnancy offers valuable insights for informing development of effective PrEP messaging strategies and programs. Finally, we evaluate whether adverse perinatal outcomes were more frequent in a cohort of Kenyan and Ugandan HIV-infected women who used TDF-containing antiretroviral therapy (ART) during pregnancy compared to HIV-infected women who used ART during pregnancy that did not contain TDF. Our findings support the growing evidence that prolonged prenatal TDF use is not associated with adverse perinatal outcomes and contribute to the few prospective studies evaluating the safety of TDF use during pregnancy from African cohorts. The studies within this dissertation aim to address these implementation science gaps and inform optimal and effective delivery of PrEP for HIV prevention to pregnant and postpartum in sub-Saharan Africa.
- Nursing - Seattle