A 26-year-old pregnant woman tested positive for HIV 4 days ago at the time of a first prenatal visit. She is at approximately 18 weeks’ gestation. Her initial laboratory studies showed a CD4 count of 380 cells/mm³, an HIV RNA of 14,470 copies/mL, normal renal function, and a negative HLA-B*5701 test. She has never received antiretroviral therapy, and results from the baseline genotype resistance assay are pending.