DEFINITIONS AND EPIDEMIOLOGY
Worldwide, an estimated 1.5 million infants are born to HIV-infected mothers each year.1 In high-income countries, where prenatal testing, maternal antiretroviral therapy, infant antiretroviral prophylaxis, cesarean delivery (when indicated), and safe alternatives to breastfeeding are widely available, the risk of perinatal transmission of HIV can be reduced to less than 2%.2 The pediatric provider plays an essential role in preventing perinatal HIV transmission through the early identification of HIV-exposed infants, timely HIV testing, and provision of infant antiretroviral prophylaxis.
Perinatal HIV transmission refers to infections that are acquired during the intrauterine, intrapartum, and postpartum periods. In the United States, the peak years of perinatal HIV transmission occurred in the early 1990s, with 1650 new infections diagnosed in 1991 alone.3 Over the past several decades, there has been a dramatic reduction in the rate of perinatal HIV transmission.3 In 2014, 127 cases of perinatal HIV infection occurred in the United States.4 These cases represent women who either refused or were not offered prenatal HIV testing, had suboptimal antiretroviral adherence during pregnancy, presented in labor without prenatal care, or experienced a rare treatment failure.
The reduction in perinatal HIV infections in high-income countries is largely attributable to antiretroviral medications. In 1994, the Pediatric AIDS Clinical Trials Group released the results of their landmark study examining the effect of a three-part regimen containing the nucleoside reverse-transcriptase inhibitor zidovudine (ZDV). The active treatment arm consisted of maternal oral ZDV therapy beginning at 14–34 weeks’ gestation, maternal intravenous ZDV in labor, and infant oral ZDV for 6 weeks. The HIV infection rate in the active treatment arm was 8% at 18 months versus 26% in the placebo group–a remarkable 68% reduction in HIV transmission.5 On the basis of these study findings, the Centers for Disease Control and Prevention (CDC) and the US Public Health Service Task Force (USPHSTF) issued recommendations in 1994 for the routine use of the three-part ZDV regimen for all pregnant HIV-infected women and their infants.6
In July 1995, the CDC adopted guidelines issued by the USPHSTF for universal prenatal HIV counseling and consensual testing.7 In 2006, the CDC revised its recommendations to include HIV screening as a routine part of prenatal care, rather than as an optional test.8 As such, they recommend “opt-out testing,” whereby all pregnant women should be tested for HIV as part of their care unless they specifically decline.8 The CDC also recommends a second HIV test be performed in the third trimester for women with known risk factors for HIV acquisition or for women in high-prevalence areas (defined by an incidence of at least one HIV infection per thousand pregnant women).8 In cases where there has been no prenatal care or maternal HIV testing during pregnancy, maternal HIV testing should be performed at the onset of labor. Early diagnosis of pregnant women is critical for timely initiation of maternal antiretroviral ...