Clinical significance of histologic chorioamnionitis with a negative amniotic fluid culture in patients with preterm labor and premature membrane rupture

Abstract

ObjectiveTo evaluate the effect of histological chorioamnionitis (HCA) with a negative amniotic fluid (AF) culture on adverse pregnancy and neonatal outcomes and inflammatory status in the AF compartment in women with preterm labor or preterm premature rupture of membranes (PPROM).MethodsThis is a retrospective cohort study of 153 women diagnosed as having a preterm labor or PPROM (20–34 weeks) who delivered singleton gestations within 48 hours of amniocentesis. AF obtained through amniocentesis was cultured, and interleukin (IL)-6, IL-8, and metalloproteinase-9 (MMP-9) levels were determined. The placentas were examined histologically.ResultsThe prevalence of HCA with negative AF culture was 23.5% (36/153). The women with HCA but with a negative AF culture (group 2) and those with a positive AF culture (group 3) had a significantly lower mean gestational age at amniocentesis and delivery than those with a negative AF culture and without HCA (group 1). Women in group 3 had the highest levels of AF IL-6, IL-8, and MMP-9, followed by those in group 2, and those in group 1. Composite neonatal morbidity was significantly higher in groups 2 and 3 than in group 1, but this was no longer significant after adjusting for confounders caused mainly by the impact of gestational age.DiscussionIn the women who delivered preterm neonates, HCA with a negative AF culture was associated with increased risks of preterm birth, intense intra-amniotic inflammatory response, and prematurity-associated composite neonatal morbidity, and its risks are similar to the risk posed by positive AF culture.

Re‐assessing microbiomes in the low‐biomass reproductive niche

“…Adverse outcomes associated with pregnancy and the early postpartum period in mothers and neonates have previously been diagnosed and treated based on traditional microbiological culture. However, there exists a vast body of literature highlighting failure of such techniques to identify specific aetiological agents, or for treatment to result in resolution of the condition or to prevent adverse outcomes . This suggests that the presence of the microorganisms alone is not causative, rather interactions between the host, the microbe, microbial components, and the environment represent a complex interplay with multiple potential outcomes.…”

Diagnostic value of Chorioquick for detecting chorioamnionitis in women with premature rupture of membranes

“…Chorioamnionitis may not manifest clinically due to low predictive probability of clinical signs, 3,5 and waiting until the time of delivery to make a histological diagnosis of chorioamnionitis (gold standard) could predispose fetuses to several potential complications. 1,[3][4][5][6] In a recent study, maternal chorioamnionitis was strongly associated with cerebral palsy, regardless of other factors at birth such as birth weight and preterm delivery. 7 Because of the subjective nature of clinical symptoms and signs for chorioamnionitis, experts in the field have put forward the case for more reliable, non-invasive, and quick assays to make a diagnosis of chorioamnionitis with reasonable accuracy.…”

“…While preterm premature rupture of membranes (PPROM) accounts for 30%–40% of spontaneous preterm deliveries, histological chorioamnionitis complicates 30%–80% of preterm births caused by PPROM . According to Higgins et al., chorioamnionitis represents intrauterine infection and/or inflammation, otherwise known as Triple‐I.…”

“…According to Higgins et al., chorioamnionitis represents intrauterine infection and/or inflammation, otherwise known as Triple‐I. Chorioamnionitis may not manifest clinically due to low predictive probability of clinical signs, and waiting until the time of delivery to make a histological diagnosis of chorioamnionitis (gold standard) could predispose fetuses to several potential complications . In a recent study, maternal chorioamnionitis was strongly associated with cerebral palsy, regardless of other factors at birth such as birth weight and preterm delivery …”

“…Tissue specimens were obtained from the placenta (at least two specimens), umbilical cord (typically one specimen), and placental membranes (at least two specimens), and representative samples of specimens were processed and embedded in paraffin tissue blocks in the histopathology laboratory by histopathologists, who were blinded to the Chorioquick results, but not to the clinical picture. Sections of formalin-fixed paraffin-embedded tissue blocks were stained with hematoxylin and eosin.Clinical chorioamnionitis was diagnosed when maternal temperature was >37.8°C, and two or more of the following criteria were present: uterine tenderness, malodorous vaginal discharge, maternal leukocytosis (>15 000 cells/mm3 ), maternal or fetal tachycardia, in line with the criteria proposed by Gibbs. 18 Histologic chorioamnionitis was defined as the presence of acute inflammatory changes in any tissue samples (amnion, chorion-decidua, umbilical cord, and chorionic plate) as described by Salafia et al 19 The primary outcome measures were sensitivity, specificity, and accuracy of the Chorioquick test.…”