Prenatal screening for HIV: A review of the evidence for the U.S. Preventive Services Task Force

Background: Each year in the United States, 6000 to 7000 women with HIV give birth. The management and outcomes of prenatal HIV infection have changed substantially since the U.S. Preventive Services Task Force issued recommendations in 1996. Purpose: To synthesize current evidence on risks and benefits of prenatal screening for HIV infection. Data Sources: MEDLINE, the Cochrane Library, reference lists, and experts. Study Selection: Studies of screening, risk factor assessment, accuracy of testing, follow-up testing, and efficacy of interventions. Data Extraction: Data on settings, patients, interventions, and outcomes were abstracted for included studies; quality was graded according to criteria developed by the Task Force. Data Synthesis: No published studies directly link prenatal screening for HIV with clinical outcomes. In developed countries, the rate of mother-to-child transmission from untreated HIV-in-fected women is 14% to 25%. Targeted screening based on risk factors would miss a substantial proportion of infected women. "Opt-out" testing policies appear to increase uptake rates. Standard HIV testing is highly (>99%) sensitive and specific, and initial studies of rapid HIV tests found that both types of testing had similar accuracy. Rapid testing can facilitate timely interventions in persons testing positive. Recommended interventions (combination an ti retro viral regimens, elective cesarean section in selected patients, and avoidance of breastfeeding) are associated with transmission rates of 1% to 2% and appear acceptable to pregnant women. Limitations: Long-term safety data for antiretroviral agents are not yet available. Data are insufficient to accurately estimate the benefits of screening on long-term maternal disease progression or other clinical outcomes, such as horizontal transmission. Conclusions: Identification and treatment of asymptomatic HIV infection in pregnant women can greatly decrease mother-to-child transmission rates.