Risk for Perinatal HIV-1 Transmission According to Maternal Immunologic, Virologic, and Placental Factors

TLDR

The study evaluates how maternal and obstetric factors interact to influence mother‑to‑child HIV‑1 transmission. A prospective observational cohort of 324 HIV‑infected women at delivery in Kinshasa compared peripartum maternal, placental, and obstetric variables between transmitter and nontransmitter women. Transmission risk ranged from 7% to 71%, with the highest risks linked to maternal p24 antigenemia (71%), high CD8⁺ counts (50%), low CD4⁺ counts (29%), and placental membrane inflammation (40%), while anemia and fever were additional correlates.

Abstract

To evaluate how maternal and obstetric factors interact to influence mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission.Prospective, observational cohort study of children born to HIV-infected women to determine child's HIV infection status. The analysis then compared peripartum maternal, placental, and obstetric variables between HIV-1 transmitter and nontransmitter women.Two large maternity wards in Kinshasa, Zaire.Consecutive sample of 324 HIV-1-infected women at delivery, with 254 HIV-seronegative women followed up as control subjects. PRINCIPAL OUTCOME MEASURES: HIV infection status of children, to classify each woman as an HIV-1 transmitter or nontransmitter.The highest transmission risk (TR) was associated with maternal p24 antigenemia (TR, 71%; relative risk [RR], 3.0; 95% confidence interval [CI], 1.7 to 5.2) and maternal CD8+ lymphocyte counts of at least 1.80 x 10(9)/L (1800/microL) (TR, 50%; RR, 2.2; 95% CI, 1.2 to 4.2). Among women with CD8+ lymphocyte counts of less than 1.80 x 10(9)/L, CD4+ lymphocyte counts of less than 0.60 x 10(9)/L were a risk factor (TR, 29%; RR, 2.2; 95% CI, 1.2 to 4.2). In women with neither high CD8+ nor low CD4+ lymphocyte counts, placental membrane inflammation was associated with perinatal transmission (TR, 40%; RR, 4.2; 95% CI, 1.3 to 13.7). In women with neither p24 antigenemia, high CD8+ or low CD4+ lymphocyte counts, nor placental membrane inflammation, the transmission risk was only 7%. Additional correlates of transmission included maternal anemia and fever, but not maternal sexually transmitted diseases.Identifiable subgroups of HIV-1-infected women based on maternal and placental characteristics had between a 7% and 71% risk of perinatal HIV-1 transmission. Not only the overall rate of transmission but the impact of different risk factors for transmission appear to vary over the course of HIV infection.