Peripartum infectious morbidity in women with preeclampsia

Abstract

Background: Dysregulated maternal systemic inflammatory response is a commonly accepted component in the pathogenesis of preeclampsia. Chronic inflammation then occurs characterized by oxidative stress, proinflammatory cytokine production, and abnormal T-cell function. Infection results in similar physiologic changes.

Objective: The objective of this study was to examine the association between the diagnosis of preeclampsia and the development of chorioamnionitis, postpartum fever, endometritis and wound infection. We hypothesize that the heightened chronic inflammatory state of preeclampsia increases the risk for maternal peripartum infection.

Study design: This was a retrospective cohort study from the Consortium on Safe Labor (CSL). In the present analysis, we included all women from the CSL database and compared their characteristics and pregnancy outcomes between those with and without a diagnosis of preeclampsia prior to labor. Women presenting with preterm prelabor rupture of membranes or were diagnosed with preeclampsia during labor or postpartum were excluded. The primary outcome was a composite of maternal peripartum infections including intrapartum chorioamnionitis, postpartum fever, endometritis, and wound infection. This outcome was compared between women with and without a diagnosis of preeclampsia prior to labor using univariable and multivariable analyses.

Results: A total of 227,052 women were eligible for the analysis, of these 14,268 (6.3%) were diagnosed with preeclampsia. In univariable analysis, the rate of composite maternal peripartum infection was higher among women with preeclampsia (4.2 versus 3.8%, p = .026). When looking at each individual component, that rates of wound infection (1.0 versus 0.5%, p < .001) and postpartum fever (8.2 versus 4.4%, p < .001) were higher among women with diagnosis of preeclampsia, whereas the rate of intrapartum chorioamnionitis was lower among women with preeclampsia (1.3 versus 1.7% p = .004). Endometritis rates did not differ between the two groups. In multivariable logistic regression, adjusted for confounding variables, including maternal race, insurance status, prepregnancy BMI, maternal age, number of fetuses, number of vaginal exams, intrauterine pressure catheter and fetal scalp electrode placement, mode of delivery, group B streptococcus positivity, maternal education level, induction of labor, prelabor rupture of membranes, tobacco use, presence of diabetes (pregestational and gestational), gestational age at delivery, and chronic hypertension, the association between preeclampsia and composite maternal peripartum infection did not persist. In fact, after controlling for these influences, women with preeclampsia showed lower rates of intrapartum chorioamnionitis (aOR 0.83, 95% CI 0.70-0.99). The rest of the individual component of the primary composite outcome, postpartum fever, endometritis, and wound infection, were not associated with the diagnosis of preeclampsia.

Conclusions: In this large cohort of women diagnosed with preeclampsia prior to labor, the rate of intrapartum chorioamnionitis was decreased and the rate of postpartum infectious morbidity was not higher compared to women without a diagnosis of preeclampsia.

Keywords: Preeclampsia; chorioamnionitis; endometritis; inflammation; peripartum infection; wound infection.