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.