Protease Inhibitor-Based Antiretroviral Prophylaxis during Pregnancy and the Development of Drug Resistance

Background. The aim of this study was to determine the development of drug resistance among pregnant women receiving a protease inhibitor-based antiretroviral prophylaxis for the prevention of mother-to-child transmission of human immunodeficiency virus (HIV). Methods. HIV-infected pregnant women without maternal indication for antiretroviral therapy were enrolled prospectively. Genotypic resistance testing was performed prior to initiation of antiretroviral prophylaxis and was repeated 4-8 weeks after cessation of antiretroviral therapy at the time of delivery. Results. Forty pregnant women with HIV infection (Centers for Disease Control and Prevention stage A1 or A2) were included. All women received an antiretroviral regimen including either fixed-dose lopinavir/ritonavir (n=33) or ritonavir-boosted saquinavir (n=7) and a backbone consisting of 2 nucleoside reverse-transcriptase inhibitors. The mean duration of antiretroviral treatment was 8.4 weeks (range, 5-22 weeks). Primary resistance mutations were found in 2 patients (nonnucleoside reverse-transcriptase inhibitor resistance, K103N; protease inhibitor resistance, G48V). Postpartum genotypic resistance revealed no new relevant resistance mutations. Conclusions. In our study no clinically significant resistance mutations developed in pregnant women receiving a short-term protease inhibitor-based antiretroviral regimen for prophylaxis of mother-to-child transmission of HIV. Future therapeutic options are therefore preserved.