Clinical predictive factors of histological chorioamnionitis: case-control study

Histological chorioamnionitis and its predictors among mothers with premature rupture of membranes delivering at tertiary hospitals in Uganda: a multicenter cross-sectional study

BACKGROUND

Histological chorioamnionitis (HCA) is a significant global threat to maternal and fetal health, with an increasing prevalence in resource-limited settings. However, data on its burden and predictors remain scarce in Africa, including Uganda. This study aimed to determine the prevalence and predictors of HCA among mothers with premature rupture of membranes (PROM) at three tertiary hospitals in Uganda.

METHODS

This multicenter cross-sectional study was conducted over a three-month period, from July to October 2023, at three tertiary hospitals in Uganda. A total of 106 women diagnosed with PROM were consecutively enrolled. Data were collected using a structured questionnaire that captured routine history-taking and physical examinations. Key information gathered included the history of liquor drainage, clinical signs of chorioamnionitis (fever, uterine tenderness, and foul-smelling liquor), labor history, and placental samples obtained after delivery for histopathological analysis. Descriptive statistics and binary logistic regression analyses were performed using STATA version 14.2. Statistical significance was set at P < 0.05, with a 95% confidence interval. Results were presented using bar charts, pie charts, and tables.

RESULTS

Among the 106 participants with PROM, 44 (41.5%) had histological chorioamnionitis. The most common histological finding was neutrophil infiltration in 22 cases (50.0%), followed by funisitis in 13 cases (29.6%). Referral status (aOR = 4.5, 95% CI: 1.511-13.315, p = 0.007) and lack of prenatal care (PNC) attendance (aOR = 9.8, 95% CI: 2.802-14.504, p = 0.000) were independently associated with histological chorioamnionitis.

CONCLUSIONS AND RECOMMENDATIONS

The prevalence of HCA in this study was notably higher than previously reported data from Uganda. Neutrophil infiltration was the most frequently observed histological lesion. Patients with PROM who were referred from other health facilities or had not attended PNC were at a higher risk of developing HCA. These findings highlight the critical need for early detection and management of HCA in mothers with PROM, particularly in resource-limited settings. Routine screening for HCA should be implemented for all women presenting with PROM, with special attention to referred cases and those without PNC. Early initiation of treatment should be considered until the diagnosis is definitively ruled out. Further research is needed to explore the underlying causes of HCA to inform targeted preventive measures.

Implementation of an EOS calculator-based protocol decreased infant antibiotic exposure in chorioamnionitis without correlation with placental histopathology

OBJECTIVE

To determine the impact of the Early Onset Sepsis (EOS) calculator on antibiotic exposure in infants born to mothers with clinical chorioamnionitis and correlate EOS calculator-guided recommendations with placental histopathology.

STUDY DESIGN

Retrospective observational study comparing infants ≥ 36 weeks gestation exposed to maternal clinical chorioamnionitis admitted to the neonatal intensive care unit (NICU) before (Group 1, n = 69) and after (Group 2, n = 139) implementation of an EOS calculator protocol for chorioamnionitis. Infant antibiotic exposure and placental pathology were reviewed. Comparisons were made using Mann-Whitney and chi-square tests.

RESULTS

There was a statistically significant decrease in antibiotic exposure from Group 1 to Group 2 (p < 0.001) with no EOS cases missed. No correlation was found between EOS calculator-based treatment and participant placental histopathology (p = 0.966).

CONCLUSION

Implementation of an EOS calculator protocol specific to our study population reduced antibiotic exposure. No correlations were found between EOS calculator-based antibiotic treatment and histological chorioamnionitis.

Quantitative Modeling to Characterize Maternal Inflammatory Response of Histologic Chorioamnionitis in Placental Membranes

PROBLEM

The placental membranes are a key barrier to fetal and uterine infection. Inflammation of the membranes, diagnosed as maternal inflammatory response (MIR) or alternatively as acute chorioamnionitis, is associated with adverse maternal-fetal outcomes. MIR is staged 1-3, with higher stages indicating more hazardous inflammation. However, the diagnosis relies upon subjective evaluation and has not been deeply characterized. The goal of this work is to develop a cell classifier for eight placental membrane cells and quantitatively characterize MIR1-2.

METHOD OF STUDY

Hematoxylin and eosin (H&E)-stained placental membrane slides were digitized. A convolutional neural network was trained on a dataset of hand-annotated and machine learning-identified cells. Overall cell class-level metrics were calculated. The model was applied to 20 control, 20 MIR1, and 23 MIR2 placental membrane cases. MIR cell composition and neutrophil distribution were assessed via density and Ripley's cross K-function. Clinical data were compared to neutrophil density and distribution.

RESULTS

The classification model achieved a test-set accuracy of 0.845, with high precision and recall for amniocytes, decidual cells, endothelial cells, and trophoblasts. Using this model to classify 53 073 cells from healthy and MIR1-2 placental membranes, we found that (1) MIR1-2 have higher neutrophil density and fewer decidual cells and trophoblasts, (2) Neutrophils colocalize heavily around decidual cells in healthy placental membranes and around trophoblasts in MIR1, (3) Neutrophil density impacts distribution in MIR, and (4) Neutrophil metrics correlate with features of clinical chorioamnionitis.

CONCLUSIONS

This paper introduces cell classification into the placental membranes and quantifies cell composition and neutrophil spatial distributions in MIR.

Histological Chorioamnionitis - Experience from a Tertiary Care Center

BACKGROUND AND OBJECTIVES

Chorioamnionitis (CA) mostly represents the presence of intra-amniotic infection. The features of the disease can be detected during histopathological examination of the delivered fetal membranes. The current study aims to explore the features of all histological chorioamnionitis cases received in the Pathology Department of a university hospital over a period of five years.

METHODS

This retrospective cross-sectional study was conducted between January 2015 and December 2019 and used data from 78 women with histologically confirmed chorioamnionitis. All data were gathered from the hospital information system. The SPSS software's statistical methods were used to show and analyze descriptive and categorical data.

RESULTS

The selected patients had an average age of 36.18 ± 6.153 years (age range 21-50 years) and different stages of the disease: 29 (37.2%) in the first stage, 25 (32%) in the second stage and the remaining 24 (30.7%) subjects in the third stage. Nearly half of cases showed concomitant umbilical cord inflammation, whereas placental inflammation occurred much less frequently. The most common cause of chorioamnionitis was bacterial infection, where Streptococcus agalactiae was the most prevalent.

CONCLUSIONS

This study showed that the majority of histological chorioamnionitis were of mild intensity (stage 1). Many cases were associated with umbilical cord and, to a lesser extent, with placental inflammation. Bacteria were the most typical cause of chorioamnionitis. The most common strain was Streptococcus agalactiae.

A Microphysiological Device to Model the Choriodecidual Interface Immune Status during Pregnancy

During human pregnancy the chorion (fetal) lines decidua (maternal) creating the feto-maternal interface. Despite their proximity, resident decidual immune cells remain quiescent during gestation and do not invade the chorion. Infection and infiltration of activated immune cells toward the chorion are often associated with preterm birth. However, the mechanisms that maintain choriodecidual immune homeostasis or compromise immune barrier functions remain unclear. To understand these processes, a two-chamber microphysiological system (MPS) was created to model the human choriodecidual immune interface under normal and infectious conditions in vitro. This MPS has outer (fetal chorion trophoblast cells) and inner chambers (maternal decidual + CD45+ cells [70:30 ratio]) connected by microchannels. Decidual cells were treated with LPS to mimic maternal infection, followed by immunostaining for HLA-DR and HLA-G, immune panel screening by imaging cytometry by time of flight, and immune regulatory factors IL-8 and IL-10, soluble HLA-G, and progesterone (ELISA). LPS induced a proinflammatory phenotype in the decidua characterized by a decrease in HLA-DR and an increase in IL-8 compared with controls. LPS treatment increased the influx of immune cells into the chorion, indicative of chorionitis. Cytometry by time of flight characterized immune cells in both chambers as active NK cells and neutrophils, with a decrease in the abundance of nonproinflammatory cytokine-producing NK cells and T cells. Conversely, chorion cells increased progesterone and soluble HLA-G production while maintaining HLA-G expression. These results highlight the utility of MPS to model choriodecidual immune cell infiltration and determine the complex maternal-fetal crosstalk to regulate immune balance during infection.

Non-invasive prediction of histologic chorioamnionitis using maternal serum markers in women with preterm prelabour rupture of membranes

PROBLEM

This study aimed to evaluate and compare the predictive accuracy of serum markers for histological chorioamnionitis (HCA) among women with preterm prelabour rupture of membranes (PPROM), and to develop a nomogram prediction model to minimize the damage of the disease.

METHOD OF STUDY

This case-control study included 153 pregnant women with PPROM with a gestational age of 20⁺⁰ ∼ 36⁺⁶ weeks. The subjects were assigned into two groups: PPROM with and without HCA. According to the results of Logistic regression analysis, the predictive equation and nomogram were generated using key parameters, and the discrimination and consistency of the model were evaluated by receiver operating characteristic (ROC) curves and calibration curves.

RESULTS

From 153 subjects with PPROM, 77 developed HCA. Compared with the PPROM without HCA group, the CRP, PCT and NLR were significantly higher in HCA group (P<0.001), and the CRP had the highest predictive value. The area under the curve (AUC) of the prediction model was 0.873, and the sensitivity and specificity of predicting HCA were 68.8% and 92.1%, respectively. And the calibration curves fitted well with the realistic situation.

CONCLUSION

Maternal serum CRP and NLR could be used as predictive biomarkers for HCA in women with PPROM, while PCT needs to be further explored due to its slightly lower predictive value. Our serum markers and gestational age at PPROM could be used as a non-invasive and convenient method to predict HCA in women with PPROM. This article is protected by copyright. All rights reserved.

Pathologist interobserver variability in diagnosing acute ascending intrauterine infection

The histologic diagnosis of acute ascending intrauterine infection permits a higher-efficacy identification of both subclinical infection and clinical chorioamnionitis, but procedures for placental pathology need to adopt a unified approach and work toward reproducible grading and staging systems. We conducted a retrospective chart review of 696 placental records from single and multiple deliveries between January 2011 and February 2020. Then, we compared original diagnoses with diagnoses based on Redline criteria, which is an internationally recognized system of staging and grading. Of the 696 cases available for review, 255 had complete medical records. Findings showed a strong degree of agreement (90%-100%) between original investigators' histological diagnoses of acute ascending intrauterine infection and a review by researchers using Redline criteria. Although interobserver agreement was good, more education is needed on Redline criteria to avoid missed cases (primarily Stage 1), support protocols for pathologists and obstetricians/gynecologists in determining which cases need to be investigated, and the development of reporting standards for acute ascending intrauterine infection and feedback mechanisms during follow-up.