Prenatal screening for HIV can inform use of interventions to reduce the risk of mother-to-child transmission. The US Preventive Services Task Force (USPSTF) previously found strong evidence that prenatal HIV screening reduced risk of mother-to-child transmission. The previous evidence review was conducted in 2012.To update the 2012 review on prenatal HIV screening to inform the USPSTF.Ovid MEDLINE, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews from 2012 to June 2018, with surveillance through January 2019.Pregnant persons 13 years and older; randomized clinical trials and cohort studies of screening vs no screening; risk of mother-to-child transmission or maternal or infant harms associated with antiretroviral therapy (ART) during pregnancy; screening yield at different intervals or in different risk groups.One investigator abstracted data; a second checked accuracy. Two investigators independently rated study quality.Mother-to-child transmission; harms of screening and treatment; screening yield.Sixty-two studies were included in this review, including 29 new studies. There remains no direct evidence on effects of prenatal screening vs no screening on risk of mother-to-child HIV transmission, maternal or infant clinical outcomes, or the yield of repeat or alternative screening strategies. New evidence confirms that combination ART is highly effective at reducing the risk of mother-to-child transmission, with some new cohort studies reporting rates of mother-to-child transmission less than 1% when combination ART was started early in pregnancy (when begun in first trimester, 0%-0.4%; when begun after first trimester, or at any time if timing of ART initiation not reported, 0.4%-2.8%). New evidence on harms of ART was also largely consistent with the previous review. Evidence from primarily observational studies found prenatal combination ART with a boosted protease inhibitor associated with increased risk of preterm delivery (range, 14.4%-26.1%). For other birth outcomes (low birth weight, small for gestational age, stillbirth, birth defects, neonatal death), results were mixed and depended on the specific antiretroviral drug or drug regimen given and timing of prenatal therapy.Combination ART was highly effective at reducing risk of mother-to-child HIV transmission. Use of certain ART regimens during pregnancy was associated with increased risk of harms that may be mitigated by selection of ART regimen. The 2012 review found that avoidance of breastfeeding and cesarean delivery in women with viremia also reduced risk of transmission and that prenatal screening accurately diagnosed HIV infection.
