Effectiveness of repeat single-dose nevirapine for prevention of mother-to-child transmission of HIV-1 in repeat pregnancies in Uganda.

Background: Single-dose nevirapine (SDNVP) is widely used to prevent mother-to-child HIV transmission in resource-limited settings. Given detection of resistant mutants among women who receive SDNVP, concerns have arisen over the efficacy of SDNVP in repeat pregnancies.
Methods: Retrospective data were collected from SDNVP-exposed and -unexposed women from the HIV Network for Prevention 012 trial who subsequently received SDNVP in another pregnancy. Prospective data were collected from pregnant women who were SDNVP exposed or unexposed before delivery. Kaplan-Meier and Cox regression analyses were used to estimate rates of HIV infection and HIV-free survival among infants born to women with or without prior SDNVP exposure.
Results: In the retrospective cohort, the infection rates were 11.3% and 16.7% for 104 infants of NVP-exposed and -unexposed mothers, respectively (P = 0.41). In the prospective cohort, among 103 infants of NVP-exposed and -unexposed mothers, the 12-month infant HIV infection rates were 20.5% and 18.7% (P = 0.81) and HIV-free survival rates were 74.4% and 78.1% (P = 0.66), respectively.
Conclusions: There was no increased risk of infant HIV infection among SDNVP-exposed women compared with -unexposed women. These findings support current international guidelines to offer SDNVP to HIV-infected pregnant women, regardless of previous SDNVP exposure, when more complex prophylaxis regimens are not available.