Time trends in the prevalence of drug resistance to antiretroviral therapy (ART) in pregnant women have not been studied. Treatment and prophylactic efficacy could be compromised by drug-resistant HIV strains. We conducted a repeated cross-sectional study of antiretroviral resistance mutations to nucleoside reverse transcriptase inhibitors (NRTIs) and nonnucleoside reverse transcriptase inhibitors (NNRTIs) and of major mutations to protease inhibitors (PIs) in virus isolates from 300 HIV-infected pregnant women in New York City from 1991 to early 2001. The overall prevalence of mutations for NRTIs from 1991 to early 2001 was higher for ART-experienced (25.6% [95% confidence interval (CI): 19.1% to 32.1%]) than ART-naive (8.6% [95% CI: 3.7% to 13.4%]) mothers (P < 0.002). For NNRTIs, the overall prevalence of mutations was somewhat higher among ART-experienced (5.8% [95% CI: 2.3% to 9.3%]) versus ART-naive (1.6% [95% CI: 0% to 3.7%]) women (P = 0.06), and increased over time for ART-naive women (0%-7.4%; P = 0.03) and ART-experienced women (0%-19.4%; P = 0.0002). The prevalence of PI-associated mutations was also higher overall among ART-experienced mothers (5.8% [95% CI: 2.3% to 9.3%] vs. 1.6% [95% CI: 0% to 3.7%]; P = 0.06), with increases over time seen for ART-naive women (0%-7.4%; P = 0.03) and ART-experienced women (0%-16.1%; P = 0.0008). The increasing prevalence of drug resistance in pregnant women, including those who are drug-naive, underscores the necessity for resistance testing to guide treatment to achieve suppression of the mother's virus.
From the *Department of Epidemiology, Boston University School of Public Health, Boston, MA; †Department of Epidemiology and Biostatistics, University of Western Ontario, London, Ontario, Canada; ‡Division of Pediatric Infectious Diseases, Department of Pediatrics, Columbia University College of Physicians and Surgeons, New York, NY; §The Women and Infants Transmission Study; and the ∥Department of Microbiology, Harvard Medical School, Boston, MA.
Received for publication April 25, 2006; accepted November 15, 2006.
Supported by the National Institutes of Health/National Institute of Allergy and Infectious Diseases/National Institute of Child Health and Human Development grant RO1 AI39144-01.
Reprints: Seth L. Welles, ScD, PhD, Department of Epidemiology, Boston University School of Public Health, 715 Albany Street, 3TE, Boston, MA 02118 (e-mail: email@example.com).