Acute and chronic chorioamnionitis and the risk of perinatal human immunodeficiency virus-1 transmission

Objective This study was undertaken to examine the prevalence of acute and chronic chorioamnionitis among women infected with human immunodeficiency virus-1 (HIV-1) and to determine the relative contribution of each to perinatal HIV-1 transmission. Study design In 227 HIV-infected women receiving intrapartum/neonatal nevirapine prophylaxis, we examined associations between fetal membrane histology, cord blood interleukin-6 (IL-6), and perinatal HIV-1 transmission. Results Acute chorioamnionitis was present in 122 of 227 specimens; chronic chorioamnionitis in 64 of 227. There was a positive correlation between acute chorioamnionitis and labor length (r = 0.208; P = .002), time of ruptured membrane (r = 0.177; P = .008), and cord IL-6 (r = 0.390; P< .001). Chronic chorioamnionitis was associated with high viral load (P = .05) and low cord IL-6 (P< .001). Severe chronic chorioamnionitis was associated with intrauterine HIV-1 transmission (odds ratio [OR] = 7.61; 95% CI = 1.04-85.5), but no correlation was demonstrated between acute chorioamnionitis and vertical transmission. Conclusion In a setting of high perinatal nevirapine use, acute chorioamnionitis was not associated with vertical HIV-1 transmission. Risk for intrauterine transmission increased significantly when chronic chorioamnionitis was present.