Non-Invasive Prediction of Histologic Chorioamnionitis in Women with Preterm Premature Rupture of Membranes

Diagnostic tests for the prediction of histological chorioamnionitis and funisitis in pregnant women with preterm premature rupture of membranes: A systematic review

BACKGROUND

Infection of the amniotic cavity is an important driver and/or consequence of preterm prelabour rupture of membranes (PPROM). Prediction of infection is challenging, limiting guidance for interventions during the antenatal period. Infection typically triggers a host inflammatory response, and non-invasive indirect markers of the maternal or fetal inflammatory response have been reported in the context of PPROM and intra-amniotic infection. Some of these markers have also been tested in amniotic fluid (AF) samples.

AIMS

This study compared markers of the inflammatory response in women with PPROM against the outcome standard of histological chorioamnionitis (HCA) or funisitis (FUS).

METHODS

Searches were conducted for studies reporting diagnostic test sensitivity and specificity for proven HCA or FUS in pregnant women with PPROM after 20 weeks' gestation. Weighted mean pooled sensitivity (Se), specificity (Sp), positive predictive value, negative predictive value, diagnostic odds ratio and 95% confidence intervals were calculated for each of the selected diagnostic tests.

RESULTS

Except ultrasonographic detection of fetal thymic involution, almost all index tests analysed showed relatively low sensitivity. Maternal white cell count, interleukin-6 (IL-6) and AF IL-6 had credible specificity. Testing of AF markers, while more consistent than serum markers, showed no clear diagnostic accuracy improvement.

CONCLUSIONS

There is a clear lack of evidence for the reliability of any individual diagnostic test to assist in the detection of HCA or FUS in women with PPROM. Combining several markers into a predictive model for improved diagnosis may be worth investigating.

Identification and characterization of plasma proteins associated with intra-amniotic inflammation and/or infection in women with preterm labor

This study aimed to identify plasma proteins that could serve as potential biomarkers for microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation (IAI) in women with preterm labor (PTL). A retrospective cohort comprised singleton pregnant women with PTL (24-34 weeks) who underwent amniocentesis. Pooled plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case-control study (concomitant MIAC/IAI cases vs. non-MIAC/IAI controls [n = 10 per group]). Eight target proteins associated with MIAC/IAI were further verified by immunoassays in a large cohort (n = 230). Shotgun proteomic analysis revealed 133 differentially expressed proteins (fold change > 1.5, P < 0.05) in the plasma of MIAC/IAI cases. Further quantification confirmed that the levels of AFP were higher and those of kallistatin and TGFBI were lower in the plasma of women with MIAC and that the levels of kallistatin and TGFBI were lower in the plasma of women with IAI than in those without these conditions. The area under the curves of plasma AFP, kallistatin, and TGFBI ranged within 0.67-0.81 with respect to each endpoint. In summary, plasma AFP, kallistatin, and TGFBI may represent valuable non-invasive biomarkers for predicting MIAC or IAI in women with PTL.

Association Analysis Between Maternal Neutrophil Ratio and the Risk of Histological Chorioamnionitis in Pregnant Women with Premature Rupture of Membranes in Late Pregnancy

Background

We aimed to investigate the association between maternal neutrophil ratio and histological chorioamnionitis (HCA) risk in pregnant women with premature rupture of membranes (PROM) in late pregnancy.

Methods

A retrospective analysis was conducted on 95 cases of women with PROM in their late pregnancy between March 2018 and August 2021. These women were divided into two groups based on the presence of HCA. General clinical data and laboratory indicators were compared between the two groups. A generalized additive model was used for curve fitting, and a segmented regression model was used to explain further the non-linear relationship between neutrophil ratio and HCA risk.

Results

After adjusting for confounding factors, the curve fitting showed a "U"-shaped curve relationship between the neutrophil ratio and the risk of HCA. When the neutrophil ratio was <76.3%, the risk of HCA exhibited a decreasing trend, but the difference was not statistically significant (adjusted OR = 0.884, 95% CI: 0.781-1.001, P = 0.053). However, when the neutrophil ratio was >76.3%, the HCA risk was significantly increased (adjusted OR = 1.339, 95% CI: 1.067-1.680, P = 0.012). Furthermore, we equally divided the neutrophil ratio into three groups. The risk of HCA was significantly increased in the low-ratio group (OR = 4.292, 95% CI: 1.247-14.706, P = 0.021) compared with the middle-ratio group, which was used as the reference group. Similarly, the HCA risk of the high-ratio group (OR = 13.145, 95% CI: 1.796-96.233, P = 0.011) was also significantly enhanced. However, there was no significant difference in HCA risk between the high-ratio and low-ratio groups (OR = 1.182, 95% CI: 0.357-3.909, P = 0.784).

Conclusion

There was a significant "U"-shaped relationship between maternal neutrophil ratio and HCA risk in women with PROM in late pregnancy.

Development and Validation of a Multivariable Predictive Model for the Risk of Histologic Chorioamnionitis in Patients with Premature Rupture of Membranes in the Late Preterm and Term

Background

This study aimed to develop and validate a model to predict histologic chorioamnionitis (HCA) risk in late preterm and term premature rupture of membranes (PROM) patients using clinical and laboratory parameters.

Methods

We conducted a retrospective study on 116 late preterm and term PROM cases, divided into a training (n=81) and a validation set (n=35). A multivariable logistic regression model was developed using the training set. Performance was assessed via the area under the receiver operating characteristic curve (AUC) and net reclassification index (NRI). Decision curve analysis (DCA) evaluated the model's clinical utility. Additionally, nomograms and a web version of the model were developed.

Results

In the training set, the combined model constructed using maternal BMI, gravidity, amniotic fluid characteristics, and prenatal white blood cell (WBC) count showed significantly higher AUC than WBC alone (0.859 vs 0.710, P=0.010), with improved accuracy and sensitivity. In the validation set, the AUC of the combined model remained higher than that of WBC, but the difference was not statistically significant (0.728 vs 0.584, P=0.173). NRI analysis indicated that the combined model improved the correct classification of HCA by 25.0% (P=0.012) compared to that of WBC alone. DCA demonstrated that the combined model had a higher net benefit than WBC in most cases. The nomograms and web version of the model provided convenient tools for clinicians to predict the risk of HCA.

Conclusion

This study successfully developed and validated a clinically feasible multivariable model to predict the risk of HCA in women with late preterm and term PROM.

Wearable sensors for prediction of intraamniotic infection in women with preterm premature rupture of membranes: a prospective proof of principle study

PURPOSE

To evaluate the use of wearable sensors for prediction of intraamniotic infection in pregnant women with PPROM.

MATERIALS AND METHODS

In a prospective proof of principle study, we included 50 patients diagnosed with PPROM at the University Hospital Zurich between November 2017 and May 2020. Patients were instructed to wear a bracelet during the night, which measures physiological parameters including wrist skin temperature, heart rate, heart rate variability, and breathing rate. A two-way repeated measures ANOVA was performed to evaluate the difference over time of both the wearable device measured parameters and standard clinical monitoring values, such as body temperature, pulse, leucocytes, and C-reactive protein, between women with and without intraamniotic infection.

RESULTS

Altogether, 23 patients (46%) were diagnosed with intraamniotic infection. Regarding the physiological parameters measured with the bracelet, we observed a significant difference in breathing rate (19 vs 16 per min, P < .01) and heart rate (72 vs 67 beats per min, P = .03) in women with intraamniotic infection compared to those without during the 3 days prior to birth. In parallel to these changes standard clinical monitoring values were significantly different in the intraamniotic infection group compared to women without infection in the 3 days preceding birth.

CONCLUSION

Our results suggest that wearable sensors are a promising, noninvasive, patient friendly approach to support the early detection of intraamniotic infection in women with PPROM. However, confirmation of our findings in larger studies is required before implementing this technique in standard clinical management.

Predictors for histological chorioamnionitis among women with preterm prelabour rupture of membranes after dexamethasone treatment: a retrospective study

OBJECTIVE

To investigate reliable biomarkers for predicting histological chorioamnionitis (HCA) in women with preterm prelabour rupture of membranes (PPROM).

DESIGN

A retrospective study.

SETTING

A maternity care hospital in Shanghai.

POPULATION

Women with PPROM before 34+0/7  weeks of gestation.

METHODS

Mean values of biomarkers were compared by two-way analysis of variance (ANOVA). Log-binomial regression models were used to assess the association between biomarkers and risk of HCA. A stepwise logistic regression model was used to develop a multi-biomarker prediction model and identify the independent predictors. The area under the receiver operating characteristic curve (AUC) was used to assess prediction performance.

MAIN OUTCOME MEASURES

The ability of the individual biomarker and the combination of multiple biomarkers to predict HCA.

RESULTS

In 157 mothers with PPROM, 98 (62.42%) women had HCA and 59 (37.58%) women did not have HCA. No significant differences were observed between the two groups in white blood cell, neutrophil or lymphocyte counts, whereas both high-sensitivity C-reactive protein (hsCRP) and procalcitonin (PCT) were significantly higher in the HCA group. HsCRP and PCT were found to be independently associated with the risk of HCA, and PCT had a larger AUC value than hsCRP (p < 0.05). The optimal multi-biomarker prediction model for HCA (AUC = 93.61%) included hsCRP at 72 hours and PCT at 48 and 72 hours, and PCT had a stronger prediction capacity than hsCRP.

CONCLUSIONS

PCT could be a reliable biomarker for the early prediction of HCA in women with PPROM within 72 hours of dexamethasone treatment.

The Role of Pancreatic Stone Protein (PSP) as a Biomarker of Pregnancy-Related Diseases

Background: Pancreatic stone protein (PSP) is a biochemical serum marker that contains levels that are elevated in various inflammatory and infectious diseases. The role of PSP in the diagnosis of these diseases seems to be more important compared to clinically established biochemical serum markers in discriminating the severity of the same diseases. Standard values for PSP in pregnant women in relation to gestational age have been reported recently. Additionally, increased PSP levels have been observed to be associated with renal dysfunction in pregnant women. The aim of this study is to evaluate the diagnostic role of PSP in pregnancy-related diseases, such as pre-eclampsia (PE), hemolysis-elevated liver enzymes, and low platelet (HELLP) syndrome. In addition, the study aims to assess its diagnostic role in inflammation-triggered diseases as preterm premature rupture of membranes (PPROM) or COVID-19-positive pregnant women. Materials and Methods: In this single-centred prospective study performed at a tertiary university hospital between 2013 and 2021, we included 152 pregnant women who were diagnosed with either PE, HELLP syndrome, or PPROM. In December 2020, in the context of the COVID-19 pandemic, the Independent Ethics Committee (IEC) approved an amendment to the study protocol. Depending on the underlying disease, single or serial-serum PSP measurements were assessed. These PSP values were compared to PSP levels of women with normal pregnancies. Results: Pregnant women diagnosed with pre-eclampsia or HELLP syndrome had significantly increased PSP values (mean 9.8 ng/mL, SD 2.6) compared to healthy singleton pregnant women (mean 7.9 ng/mL, SD 2.6, p ≤ 0.001). There was no difference in serum PSP in pregnant women with PPROM compared to women with uncomplicated singleton pregnancies (mean in PPROM: 7.9 ng/mL; SD 2.9 versus mean in healthy pregnancies: 7.9 ng/mL; SD 2.6, p = 0.98). Furthermore, no difference in the PSP values in women with or without intra-amniotic infection was observed (infection: mean 7.9 ng/mL; SD 2.8 versus no infection: mean 7.8 ng/mL; SD 3, p = 0.85). The mean value of PSP in COVID-19-infected women during pregnancy (8.5 ng/mL, SD 2.3) was comparable to healthy singleton pregnancies (mean 7.9 ng/mL, SD 2.6), p = 0.24. Conclusions: The novel serum biomarker PSP is significantly upregulated in pregnant women with pre-eclampsia and HELLP syndrome. Our observations call for the further evaluation of PSP in randomized controlled clinical trials to demonstrate the actual role of PSP in pregnancy-related diseases and whether it may provide new approaches for the management and discrimination of the severity of these gestational conditions.

Clinical characteristics, complications, and predictive model of histological chorioamnionitis in women with preterm premature rupture of membranes

We aimed to analyze the impact of histological chorioamnionitis (HCA) in the presence of preterm premature rupture of the membranes (PPROM) on obstetric and neonatal outcomes, and its possible predictability. A retrospective cohort analysis of PPROM cases (20-37 weeks) was conducted comparing the patients with and without HCA, seeking a predictive model of HCA using logistic regression. A total of 295 cases of PPROM were selected, of which 72 (24.4%) had HCA. The group with HCA had a shorter latency period and a greater number of clinical and laboratory criteria in the evolution. The group with HCA had a worse comparative result and presented: lower gestational age at delivery, lower average birth weight, lower Apgar scores, longer neonatal hospitalization, worse maternal clinical conditions and, higher rates of stillbirth, low birth weight (LBW), very low birth weight (VLBW), complications in pregnancy and childbirth, and cesarean delivery due to fetal distress or chorioamnionitis. A predictive model for HCA was developed, with the following independent variables: abdominal pain (odds ratio [OR] = 11.61), uterine activity (noticeable contractions on physical exam) (OR = 5.97), fever (OR = 5.77), latency > 3 days (OR = 2.13), and C-reactive protein (OR = 1.01). With this model, an adequate receiver operating characteristic curve was found, with an area under the curve of 0.726, and some HCA probability curves were constructed for different clinical situations. In this novel study, we present a non-invasive predictive model, with clinical and laboratory variables, which may help in decision-making in a patient with PPROM.

Plasma proteomic analysis to identify potential biomarkers of histologic chorioamnionitis in women with preterm premature rupture of membranes

Introduction

To identify potential biomarkers in the plasma that could predict histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM), using shotgun and targeted proteomic analyses.

Methods

This retrospective cohort study included 78 singleton pregnant women with PPROM (24–34 gestational weeks) who delivered within 96 h of blood sampling. Maternal plasma samples were analyzed by label-free liquid chromatography-tandem mass spectrometry for proteome profiling in a nested case-control study design (HCA cases vs. non-HCA controls [n = 9 each]). Differential expression of 12 candidate proteins was assessed by multiple reaction monitoring-mass spectrometry (MRM-MS) analysis in individual plasma samples from cases and controls matched by gestational age at sampling (n = 40, cohort 1). A validation study was further performed in an independent study group (n = 38, cohort 2) using ELISA and turbidimetric immunoassay for three differentially expressed proteins.

Results

Shotgun proteomics analyses yielded 18 proteins that were differentially expressed (P < 0.05) between HCA cases and non-HCA controls. MRM-MS analysis of 12 differentially expressed proteins further revealed that the CRP, C4A, and SAA4 levels were significantly increased in women with HCA. A multi-marker panel comprising plasma SAA4 and C4A showed enhanced potential for differentiating HCA from non-HCA women (area under the curve = 0.899). Additional validation of these findings by ELISA assays revealed that the CRP levels were significantly higher in women with HCA than in those without HCA, whereas the plasma levels of C4A and SAA4 did not significantly differ between the two groups.

Conclusions

Plasma C4A, SAA4, and CRP were identified as potential biomarkers for detecting HCA in women with PPROM, based on targeted and shotgun proteomic analyses, showing good accuracy when used as a combined dual-biomarker panel (C4A and SAA4). Nevertheless, ELISA validation of these proteins, except for CRP, may not yield clinically useful markers for predicting HCA.

High-throughput analysis of amniotic fluid proteins associated with histological chorioamnionitis in preterm premature rupture of membranes using an antibody-based microarray

PROBLEM

To identify potential proteins in the amniotic fluid (AF) that may be associated with histologic chorioamnionitis (HCA) in patients with preterm premature rupture of membranes (PPROM) using antibody-based microarray analysis.

METHOD OF STUDY

This was a retrospective cohort study involving 100 singleton pregnant women with PPROM at 24-34 weeks who underwent amniocentesis and delivered within 120 h of amniocentesis. First, the AF proteomes of 15 patients with PPROM and HCA were compared with those of 15 gestational age-matched patients without HCA using a protein microarray. Next, 12 candidate proteins associated with HCA were further validated in 100 consecutive patients with PPROM by ELISA.

RESULTS

Of 507 proteins assessed in the microarray analysis, 46 showed significant intergroup differences. Further quantification confirmed that the levels of EN-RAGE, IL-6, MMP-9, TNFR2, SPARC, TSP2, and uPA were higher in the AF of PPROM patients with HCA than in those without. Multivariate analyses also showed that elevated AF EN-RAGE, IL-6, MMP-9, and TNFR2 levels were independently associated with HCA when adjusted for baseline variables. The frequency of the highest quartile of the aforementioned proteins significantly increased as the total grade of HCA increased; the risk of HCA significantly increased with increasing AF levels of each protein (P for trend < .001).

CONCLUSIONS

Using protein-antibody microarray technology, we discovered several potential AF proteins (EN-RAGE, IL-6, MMP-9, and TNFR2) independently associated with HCA in patients with PPROM. Furthermore, we demonstrated a direct correlation between the gradation of the intra-amniotic inflammatory response and HCA severity.

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.

Plasma E-selectin and kallistatin as predictive markers of histologic chorioamnionitis in women with preterm premature rupture of membranes

PROBLEM

We aimed to assess the predictive potential of 12 plasma biomarkers to predict acute histologic chorioamnionitis (HCA) in women with preterm premature rupture of membranes (PPROM) and to develop multi-biomarker panels based on these biomarkers in combination with widely used conventional laboratory markers.

METHOD OF STUDY

This was a retrospective cohort study involving 81 singleton pregnant women (24-34 weeks of gestation) who delivered within 96 h of blood sampling. White blood cell (WBC) count, differential counts, and C-reactive protein (CRP) levels were measured at admission. The levels of DKK-3, Fas, haptoglobin, IGFBP-2, kallistatin, MIP-1α, MMP-2, MMP-8, pentraxin 3, progranulin, E-selectin, and P-selectin were evaluated by ELISA using stored plasma samples. The primary outcome measure was acute HCA.

RESULTS

Multivariate analyses showed that low plasma E-selectin and kallistatin levels were independently associated with HCA occurrence after adjusting for gestational age. Using a stepwise regression analysis, a multi-biomarker panel comprising plasma E-selectin, serum CRP, and WBC was developed, which provided a good prediction of acute HCA in women with PPROM (area under the curve [AUC], 0.899), with a significantly higher AUC than that of any single variable included in the panel (P<0.05). The plasma levels of DKK-3, Fas, haptoglobin, IGFBP-2, MIP-1α, MMP-2, MMP-8, pentraxin 3, and P-selectin were not significantly associated with HCA occurrence.

CONCLUSIONS

This study identified E-selectin and kallistatin as potential plasma biomarkers associated with acute HCA in women with PPROM. Their combined analysis with serum CRP and WBC counts significantly improved acute HCA diagnosis. This article is protected by copyright. All rights reserved.

Neutrophil to Lymphocyte Ratio in Maternal Blood: A Clue to Suspect Amnionitis

There is no information about whether maternal neutrophil to lymphocyte ratios (NLRs) progressively increase with respect to the progression of acute histologic chorioamnionitis (acute-HCA) and increased maternal NLR is a risk factor for amnionitis, known as advanced acute-HCA, in pregnant women at risk for spontaneous preterm birth (PTB). The objective of the current study is to examine this issue. The study population included 132 singleton PTB (<34 weeks) due to either preterm labor or preterm-PROM with both placental pathology and maternal CBC results within 48 h before delivery. We examined maternal NLRs according to the progression of acute-HCA in extra-placental membranes (EPM) (i.e., group-0, inflammation-free EPM; group-1, inflammation restricted to decidua; group-2, inflammation restricted to the membranous trophoblast of chorion and the decidua; group-3, inflammation in the connective tissue of chorion but not amnion; group-4, amnionitis). Maternal NLRs significantly and progressively increased with the progression of acute-HCA (Spearman’s rank correlation test, γ = 0.363, p = 0.000019). Moreover, the increased maternal NLR (≥7.75) (Odds-ratio 5.56, 95% confidence-interval 1.26-24.62, p < 0.05) was a significant independent risk factor for amnionitis even after the correction for potential confounders. In conclusion, maternal NLRs significantly and progressively increased according to the progression of acute-HCA and the increased maternal NLR (≥7.75) was an independent risk factor for amnionitis in spontaneous PTB. The evaluation of the performance of NLR should clearly require a prospective description of this parameter in a cohort of patients with either threatened PTL or preterm-PROM.

Maternal inflammatory markers for chorioamnionitis in preterm prelabour rupture of membranes: a systematic review and meta-analysis of diagnostic test accuracy studies

BACKGROUND

There is no consensus on the role of inflammatory markers in identifying chorioamnionitis in preterm prelabour rupture of membranes (PPROM). We set out to evaluate the accuracy of maternal blood C-reactive protein (CRP), procalcitonin and interleukin 6 (IL6) in diagnosis of histological chorioamnionitis and/or funisitis (HCA/Funisitis) in PPROM.

METHODS

We searched MEDLINE, EMBASE and The Cochrane Library from inception to January 2020 for studies where maternal blood CRP, procalcitonin or IL6 was assessed against a reference standard of HCA/Funisitis in PPROM. The Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2) tool was used to assess methodological quality. Hierarchical summary receiver operating characteristic (SROC) models were used to construct summary curves. Bivariate models were used to obtain summary estimates for studies with the same cut-off.

RESULTS

We included 23 studies reporting HCA/Funisitis in 902 of 1717 women, median prevalence 50% (inter-quartile range 38-57). Of these studies, 20 were prospective cohort design and 3 were retrospective cohort. Eleven studies reported the index test against a reference standard of HCA and/or funisitis, 10 reported HCA alone and 2 reported funisitis alone. Many studies had high risk of bias scores on the QUADAS-2 assessment but low concerns for applicability. Sensitivity and specificity for CRP ≥ 20 mg/L (5 studies, 252 participants) was 59% (95% CI 48-69) and 83% (95% CI 74-89) respectively. SROC curves are provided for each index test. At selected specificity of 80%, the sensitivities for CRP (all cut-offs, 17 studies, 1404 participants), PCT ( all cut-offs, 6 studies, 231 participants) and IL6 (all cut-offs, 5 studies, 299 participants) were 59%(95% CI 52-68), 56%(95% CI 50-69) and 52% (95% CI 50-86) respectively.

CONCLUSIONS

There is insufficient evidence to support use of CRP, procalcitonin or IL6 in maternal blood for diagnosis of HCA/Funisitis in PPROM. This review followed recommended methodology and data analytic methods that made the most of the data regardless of the different cut-offs used. However, the evidence is based on few studies with generally small sample sizes, poor-quality scores and substantial heterogeneity. There is a need for good-quality diagnostic accuracy studies to better assess the role of these biomarkers in PPROM.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number: CRD42015023899, registered on 8 October 2015.

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

OBJECTIVE

To determine the accuracy of a semi-quantitative interleukin-6 (IL-6) vaginal secretion rapid test (Chorioquick) for detecting chorioamnionitis in women with premature rupture of membranes (PROM).

METHODS

A prospective cohort study in five tertiary hospitals in Nigeria involved women with confirmed PROM at term and preterm PROM with or without suspected chorioamnionitis from August 1, 2017, to October 31, 2018. Cervicovaginal fluid samples were tested for chorioamnionitis using the Chorioquick test. Samples were repeated at decision to deliver. The test was considered positive if at least the indicator 'IL-6 low' of the three Chorioquick biomarkers (low, medium, high) was positive, or negative if none of the biomarkers were positive. Chorioamnionitis was histologically confirmed post-delivery using three tissue samples. Primary outcome measures were sensitivity, specificity, and accuracy.

RESULTS

Of 73 women, on histological confirmation, 39 were true positive and 29 were true negative (for chorioamnionitis) to the Chorioquick test at repeat assessment. Overall, the Chorioquick test had a sensitivity of 97.5% (95% confidence interval [CI] 85.3-99.9), specificity 87.9% (70.9-96.0), and accuracy 93.2% (79.5-99.1). Sub-group analysis of women <37 weeks of pregnancy showed a sensitivity of 100.0% (95% CI 83.4-100.0), specificity of 91.3% (70.5-98.5), and accuracy of 95.8% (82.5-99.5). Triple positive samples were 100.0% specific in all gestations.

CONCLUSION

Chorioquick showed favorable utility for detecting chorioamnionitis in PROM and could be a reliable, non-invasive rapid tool in a real-world clinical setting.

A perfect storm: fetal inflammation and the developing immune system

Histologic chorioamnionitis is an inflammatory disorder of the placenta that commonly precedes preterm delivery. Preterm birth related to chorioamnionitis and fetal inflammation has been associated with a risk for serious inflammatory complications in infancy. In addition, preterm infants exposed to chorioamnionitis may be more susceptible to infection in the neonatal intensive care unit and possibly later in life. A significant body of work has established an association between chorioamnionitis and inflammatory processes. However, the potential consequences of this inflammation on postnatal immunity are less understood. In this review, we will discuss current knowledge regarding the effects of fetal exposure to inflammation on postnatal immune responses.

[Maternal neutrophil-to-lymphocyte ratio as a prognostic biomarker for placental inflammatory response in late pregnancy]

OBJECTIVE

To investigate the association between maternal serum neutrophil-lymphocyte ratio (NLR) and placental inflammatory response (PIR) in late pregnancy.

METHODS

We retrospectively analyzed the clinical and follow-up data of 478 pregnant women undergoing routine prenatal examination and delivery in our hospital in the year 2016. According to the placental pathological results, the women were divided into PIR group (238 cases) and control group (240 cases). The levels of serum inflammatory makers including leukocytes, neutrophils, lymphocytes, C-reactive protein (CRP) and NLR were compared between the two groups to analyze the association of these markers with PIR. Multivariate analysis was performed to identify the independent risk factors of PIR. Logistic regression model was established and the area under the receiver operating characteristic curve (ROC) was used for analyzing the prognostic value of these makers in late pregnancy.

RESULTS

The areas under the curve (AUC) of leukocytes, neutrophils, lymphocytes, CRP and NLR were 0.698 (95%CI: 0.485-0.766), 0.716 (95%CI: 0.453-0.783), 0.329 (95%CI: 0.228-0.431), 0.725 (95%CI: 0.677-0.765) and 0.801 (95%CI: 0.742-0.856), respectively. After adjusting the confounders, multivariate logistic regression analysis showed that preterm labor (OR=2.446, 95%CI: 1.003-4.590), premature rupture of membranes (OR=2.304, 95%CI: 1.049-4.161), NLR &gt; 7 (OR=3.268, 95%CI: 2.071-6.920), and CRP &gt; 15 mg/L (OR=2.137, 95%CI: 1.412-8.236) were independent risk factors for PIR.

CONCLUSIONS

An increased NLR in late pregnancy can serve as an effective indicator for predicting the risk of PIR.

Antibody Microarray Analysis of Plasma Proteins for the Prediction of Histologic Chorioamnionitis in Women With Preterm Premature Rupture of Membranes

We aimed to identify maternal blood biomarkers predictive of histologic chorioamnionitis (HCA) in the plasma of women with preterm premature rupture of membranes (PPROM) and to determine whether the combination of these biomarkers with conventional clinical variables can improve the prediction of HCA. This retrospective cohort study included 82 consecutive women with PPROM (23-34 gestational weeks) who delivered within 96 hours of blood sampling. A membrane-based human antibody microarray was used to analyze the plasma proteome. The validation of 5 candidate biomarkers of interest was performed by enzyme-linked immunosorbent assay (ELISA) in the final cohort (n = 82). Serum C-reactive protein (CRP) levels were measured at sampling. Seventy-nine molecules studied exhibited intergroup differences. Validation by ELISA confirmed higher levels of plasma matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), S100 A8/A9, and insulin-like growth factor-binding protein 1 (IGFBP-1), but not tissue inhibitor of metalloproteinase 1 (TIMP-1), in women with HCA than in women without HCA. Using a stepwise regression analysis, a combined prediction model was developed, which included the plasma MMP-9, serum CRP levels, and gestational age (area under the curve [AUC], 0.932). The AUC for this model was significantly greater than that for any single variable included in the predictive model. Protein-antibody microarray technology can be useful in identifying plasma-based predictors for HCA. This study suggests that plasma MMP-9, IL-6, IGFBP-1, and S100 A8/A9 are important noninvasive predictors for HCA in women with PPROM and that the best predictive model, which combined these biomarkers with conventional clinical factors, can significantly improve the predictability for HCA.

Immune biomarkers in maternal plasma to identify histologic chorioamnionitis in women with preterm labor

PURPOSE

To determine whether various selected immune-related proteins in maternal plasma, alone or in combination, can predict histologic chorioamnionitis (HCA) in women with preterm labor, and to compare the predictive abilities of these biomarkers with that of serum C-reactive protein (CRP).

METHODS

This retrospective cohort study included 74 consecutive women with preterm labor (23-34 gestational weeks) who delivered within 96 h of blood sampling. Their serum CRP levels were also measured. The stored maternal plasma was assayed for interleukin (IL)-6, matrix metalloproteinase (MMP)-9, tissue inhibitor of metalloproteinases (TIMP)-1, angiopoietin-2, S100 A8/A9, CXCL14, APRIL, and insulin-like growth factor-binding protein-2 (IGFBP-2), using ELISA kits. The primary outcome measure was HCA.

RESULTS

HCA was detected in 59.4% (44/74) of women. Women with HCA had a significantly lower median gestational age at sampling and plasma IGFBP-2 level, and higher median plasma IL-6 and S100 A8/A9 levels than those without HCA. In multivariable analysis, high plasma IL-6 and low plasma IGFBP-2 levels were independently associated with the occurrence of HCA. However, the sensitivities, specificities, and areas under the curve of plasma IL-6, S100 A8/A9, and IGFBP-2, alone or in combination, were similar to or lower than those of serum CRP, for detecting HCA.

CONCLUSIONS

Our data suggest that plasma IL-6, S100 A8/A9, and IGFBP-2 could be potential novel biomarkers for predicting HCA in women with PTL; however, elevated plasma levels of these biomarkers, alone or in combination, do not predict HCA better than serum CRP.

Cytokine Changes in Maternal Peripheral Blood Correlate With Time-to-Delivery in Pregnancies Complicated by Premature Prelabor Rupture of the Membranes

Premature prelabor rupture of the membranes (PPROM) causes one-third of preterm births worldwide and is most likely caused by subclinical intrauterine infection and/or inflammation. We proposed that women with systemic inflammation at the time of PPROM would have shorter latency. Peripheral blood samples were collected from 20 singleton pregnant women with PPROM between 23 ± 1 and 33 ± 6 weeks. The first sample was drawn within 48 hours of admission, followed by weekly blood draws until delivery. Pregnancies complicated with acute chorioamnionitis, preeclampsia, intrauterine growth restriction, obesity, substance abuse, and chronic maternal disease were excluded. Twenty uncomplicated, gestational age-matched pregnancies served as controls. Plasma concentration of 39 cytokines was measured longitudinally using Luminex assays to investigate their value as predictive biomarkers of latency. Women with PPROM exhibited significantly lower plasma concentration of interferon-γ-inducible protein 10-Chemokine (c-x-c motif; IP10/CXCL10), Chemokine (c-x-c motif) Ligand 9 (MIG/CXCL9), Platelet-derived growth factor BB (PDGFbb), and cutaneous T cell-attracting chemokine, also known as CCL27/CCL27 than controls at admission but significantly elevated interleukin (IL)1RA, tumor necrosis factor α, monocyte chemotactic protein-1/CCL2 at delivery compared to admission. Women with PPROM who delivered within 7 days had significantly lower plasma concentration of anti-inflammatory cytokine IL1RA than those with latency periods >7 days. The IL1RA and endotoxin activity in conjunction with clinical parameters results in excellent prediction of latency to delivery (area under the receiver-operating characteristic curve = 0.91). We concluded that higher levels of anti-inflammatory cytokines in women with PPROM were associated with increased latency until delivery, likely due to counterbalancing of proinflammatory load. When used in conjunction with other predictive characteristics of time until delivery, cytokines may further assist clinical decision-making and optimize pregnancy outcomes in women with PPROM.

Does intact umbilical cord milking increase infection rates in preterm infants with premature prolonged rupture of membranes?

Objective: To investigate whether intact umbilical cord milking (I-UCM) can aggravate infection or result in other undesirable complications in preterm infants with premature prolonged rupture of membranes (PPROM).Methods: Neonates vaginally delivered between 28 and 37 weeks' gestation and complicated by PPROM before birth were randomly divided into two groups according to the cord clamping procedure: I-UCM before clamping and immediate cord clamping (ICC). Various parameters of the study participants were compared between the two groups.Results: Of 102 preterm infants, 48 and 54 were randomly allocated to the I-UCM and ICC groups, respectively. There were no significant differences between the two groups regarding hematological parameters (platelet count, white blood count, neutrophil ratio, and C-reactive protein) or neonatal outcomes (probable or certain neonatal infection, respiratory distress syndrome, necrotizing enterocolitis, and intraventricular hemorrhage) (p > .05). However, preterm neonates in the I-UCM group had higher serum hemoglobin and hematocrit levels (p < .05) and received fewer blood transfusions (p < .05) than those in the ICC group.Conclusion: Milking the umbilical cord to a preterm neonate with PPROM will not aggravate neonatal infection or result in other undesirable complications. This simple procedure will improve hemoglobin values and hematocrit levels and may lessen the need for transfusion during the neonatal period.

Inflammatory proteins in maternal plasma, cervicovaginal and amniotic fluids as predictors of intra-amniotic infection in preterm premature rupture of membranes

Objective

We aimed to assess the correlations among multiple cytokine concentrations in the maternal plasma, cervicovaginal fluid (CVF), and amniotic fluid (AF) compartments in women with preterm premature rupture of membranes (pPROM), and to develop a prediction model based on non-invasive measures, having better sensitivity and specificity for the identification of microbial invasion of amniotic cavity (MIAC).

Method

This retrospective study included 75 consecutive women with pPROM (20+0–34+0 weeks), who underwent amniocentesis. Both maternal plasma and CVF samples were collected at the time of amniocentesis. Stored AF, plasma and CVF samples were assayed for cytokine levels [interleukin (IL)-6, IL-8, monocyte chemotactic protein-1, macrophage inflammatory protein (MIP)-1α, MIP-1β] using a multiplex immunoassay kit.

Results

Levels of inflammatory proteins measured in the CVF were significantly correlated with AF proteins levels, whereas none of the proteins in plasma correlated significantly with any in the AF or CVF. Proteins levels measured in the AF and CVF were significantly higher in women with MIAC compared to those without, whereas only high levels of IL-6 in plasma were significantly associated with MIAC. By using stepwise regression analysis, a non-invasive model (using clinical factors and CVF cytokine levels) for the prediction of MIAC was developed; the area under curve of this non-invasive model was similar to that of the invasive model (using clinical factors and AF cytokines).

Conclusions

The levels of inflammatory proteins in the CVF correlated with those in the AF, whereas those in the plasma showed no correlation. A non-invasive model using clinical factors and CVF cytokine levels predicted the risk of MIAC in women with pPROM.

Amniotic Fluid Infection in Preterm Pregnancies with Intact Membranes

Introduction. Intra-amniotic infection (IAI) is a major cause of preterm labor and adverse neonatal outcome. We evaluated amniotic fluid (AF) proteolytic cascade forming biomarkers in relation to microbial invasion of the amniotic cavity (MIAC) and IAI in preterm pregnancies with intact membranes. Material and Methods. Amniocentesis was made to 73 women with singleton pregnancies; 27 with suspected IAI; and 46 controls. AF biomarkers were divided into three cascades: Cascade 1: matrix metalloproteinase-8 (MMP-8), MMP-9, myeloperoxidase (MPO), and interleukin-6; Cascade 2: neutrophil elastase (HNE), elafin, and MMP-9; Cascade 3: MMP-2, tissue inhibitor of matrix metalloproteinases-1 (TIMP-1), MMP-8/TIMP-1 molar ratio, and C-reactive protein (CRP). MMP-8 was measured by an immunoenzymometric assay and the others were measured by ELISA. Standard biochemical methods, molecular microbiology, and culture techniques were used. Results. MMP-8, MMP-9, MPO, elafin, and TIMP-1 concentrations were higher in IAI suspected cases compared to controls and also in IAI suspected cases with MIAC compared to those without MIAC when adjusted by gestational age at amniocentesis. All biomarkers except elafin and MMP-2 had the sensitivity of 100% with thresholds based on ROC-curve. Odd ratios of biomarkers for MIAC were 1.2-38 and 95% confidential intervals 1.0-353.6. Conclusions. Neutrophil based AF biomarkers were associated with IAI and MIAC.

Comparison of the duo of insulin-like growth factor binding protein-1/alpha fetoprotein (Amnioquick duo+®) and traditional clinical assessment for diagnosing premature rupture of fetal membranes

PURPOSE

To determine the diagnostic accuracy of insulin-like growth factor binding protein-1/alpha fetoprotein (Amnioquick duo+®) compared with traditional clinical assessment (TCA) of nitrazine, ferning and pooling for the diagnosis of prelabor rupture of membranes (PROM).

METHODS

A double-blinded, multicenter clinical study was conducted between February 2015 and August 2015 among pregnant women presenting with symptoms or features suggestive of PROM between 24 and 42 weeks gestation. Confirmation of PROM was done after delivery based on the presence of any two of these criteria: delivery within 48 h to 7 days, evidence of chorioamnionitis, membranes explicitly ruptured at delivery and adverse perinatal outcomes strongly correlated with prolonged PROM. Sensitivity, specificity and accuracy were outcome measures assessed.

RESULTS

Two hundred and thirty-six women were recruited. Three women were excluded from the final analysis due to lack of follow-up data and failure to meet inclusion criteria. Two hundred and thirty-three women had complete data for analysis. The specificity and sensitivity values for TCA were 76.2% and 85.2%, which were lower than those of Amnioquick duo+, which were 97.6% and 97.9%, respectively. The accuracy of Amnioquick duo+ was statistically higher (97.9% vs. 83.7%; RR=1.17; 95%CI=1.10-1.24; P<0.001). In equivocal cases (pooling=negative), the accuracy of Amnioquick duo+ vs. TCA was 98.4% vs. 69.4% (RR=1.42; 95%CI=1.20-1.68; P<0.001) at ≥34 weeks gestation and 100.0% vs. 71.4% (RR=1.40; 95%CI=1.07-1.83; P=0.021) at <34 weeks gestation.

CONCLUSION

The performance matrix of Amnioquick duo+® was superior to that of TCA for diagnosing PROM even in equivocal cases.

Predictive value of procalcitonin or c-reactive protein for subclinical intrauterine infection in patients with premature rupture of membranes (PROM)

INTRODUCTION

to evaluate the diagnostic value of procalcitonin (PCT) and C-reactive protein (CRP) for the prediction of subclinical intrauterine infection in patients with premature rupture of membranes (PROM).

METHODS

a retrospective analysis was performed based on patients with PROM admitted into our hospital between January 2011 and January 2016. Using the pathological diagnosis of placenta as the gold standard, the sensitivities, specificities, positive predictive values, and negative predictive values of PCT and CRP for the diagnosis of subclinical intrauterine infection at different gestational weeks were analyzed. Further, the diagnostic accuracies were compared according to their receiver operating characteristic (ROC) curves.

RESULTS

276 cases were included. The area under the ROC curve of CRP is 0.632, and it is significantly better than PCT. The sensitivity, specificity, positive predictive value, and negative predictive value of CRP are 0.686, 0.958, 0.501, and 0.765, which are all better than those of PCT. The group analysis according to different gestational weeks demonstrated that for the group of 28-33+6 weeks pregnant women, the area under the ROC curve of CRP and PCT is 0.869, and 0.787. The both test have satisfactory accuracy. But the sensitivity and specificity of PCT is 0.830, and 0.950, respectively. That are significantly better than CRP.

CONCLUSION

both PCT and CRP have good application potential for the diagnostic prediction of subclinical intrauterine infection in <34 gestational weeks pregnant women with PROM, and PCT is more applicable to 28-33+6 gestational weeks pregnant women with PROM.