Primary human immunodeficiency virus infection during pregnancy detected by repeat testing.

Objective: The purpose of this study was to describe characteristics of pregnant women with newly acquired human immunodeficiency virus (HIV) infection that was identified by repeat testing.

Study Design: The Centers for Disease Control and Prevention-sponsored Mother-Infant Rapid Intervention at Delivery (MIRIAD) study, which was conducted in 6 US cities, encouraged repeat HIV testing during pregnancy to identify primary infections.

Results: Fifty-four HIV-infected women were identified. Four primary HIV infections were recognized, with median estimated seroconversion at 22 weeks of gestation. All 4 women denied new sex partners, alcohol, and illegal drug use during pregnancy. Three of the 4 mother-infant pairs received antiretroviral medications. One infant was infected perinatally, with positive HIV DNA polymerase chain reaction at birth. Questionnaire data identified 2 additional women with HIV that was likely acquired during pregnancy (identified by rapid testing at labor and delivery), which suggests that 6 of 54 HIV-infected women (11%) in the MIRIAD study had primary infection during pregnancy.

Conclusion: Repeat HIV testing in pregnancy can identify opportunities for antiretroviral prophylaxis and should be used in areas of high HIV prevalence.