Repeat third trimester HIV testing: An opportunity to prevent maternal to child transmission

Issues: Efforts to reduce maternal to child transmission (MTCT) of HIV have been highly successful, but perinatal infections continue to occur. The CDC and ACOG recommend repeat third trimester HIV testing in Illinois based on statewide estimates of disease burden. However, this testing is recommended but not legislated, and maternal seroconversion in pregnancy after an initial negative test contributes to ongoing cases of MTCT in Illinois.

Description: The statewide Perinatal HIV Hotline receives reports of positive HIV tests in pregnancy. Hotline reports between 2007-2014 were reviewed to identify cases of seroconversion in pregnancy. Cases were defined by a documented negative maternal HIV test during pregnancy followed by a confirmed positive HIV test later in pregnancy or at delivery. Women with postpartum diagnoses were determined to have seroconverted during pregnancy based upon HIV infection in the child in the absence of sustained breastfeeding. Fourteen cases (13 known and 1 suspected) of maternal seroconversion were identified.

Lessons Learned: Maternal HIV seroconversion in pregnancy is rare but can be missed without repeated testing and poses a high risk for MTCT. In 7 of 14 (50%) seroconversion cases, MTCT occurred. Diagnosis antenatally can mitigate this risk. Of the five maternal HIV diagnoses discovered before delivery, none resulted in infant HIV infection.

Recommendations: Identification of HIV acquisition during pregnancy is critical to achieving perinatal HIV elimination. Universal repeat third trimester HIV testing can identify maternal HIV seroconversion and prevent ongoing cases of MTCT. Mandated repeat testing should be recommended for all pregnant women in Illinois.