619: Mechanical dilation in HIV positive subjects does not increase risk of histologic chorioamnionitis

Abstract

Chorioamnionitis is a risk factor for perinatal HIV transmission and early-onset neonatal sepsis. Placental inflammation increases risk of HIV transmission. The objective of this study is to explore the risk of histologic chorioamnionitis in HIV-1 positive subjects undergoing induction of labor with and without mechanical dilation. This is a multi-center retrospective cohort study of HIV positive women who underwent induction/augmentation of labor from 11/2010 – 8/2017 at two major tertiary care centers in different states. Delivery outcomes including: histologic and clinical chorioamnionitis, postpartum endometritis, and neonatal HIV infection were included for analysis. A bivariate analysis of demographic, HIV specific, and delivery outcome measures between the cohorts was conducted. Multivariate logistical regression modeling was used to control for possible confounding variables. A total of 396 HIV+ women delivered during the study period. 135 women met inclusion criteria and 95 had placental pathology available for review. 83 women (61.5%) underwent mechanical dilation and 51 (38.5%) had no mechanical dilation. The cohorts were similar in terms of race/ethnicity, age, parity, HIV viral load, CD4 count, and GBS status. The mechanical dilation cohort had less cervical dilation on admission compared to the control. 20 subjects had histologic chorioamnionitis (21.05%). There was no difference in rates of histologic chorioamnionitis between the cohorts with 14 (22.22%) of the mechanical dilation cohort and 6 (18.75%) of the no mechanical dilation cohort having evidence of histologic chorioamnionitis (p = 0.6951, OR 1.24 [CI 0.43-3.60]). A multi-variate logistic regression model was developed to control for race, age, and dilation on admission and did not change the outcome or significance. Clinical chorioamnionitis, postpartum endometritis, and neonatal HIV infection were rare with 4, 3, and 0 cases respectively in this study population. The use of mechanical dilation was not shown to be associated with increased risk of histologic chorioamnionitis in term HIV positive patients undergoing induction or augmentation of labor.