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

Short-term variation of the fetal heart rate as a marker of intraamniotic infection in pregnancies with preterm prelabor rupture of membranes: a historical cohort study

INTRODUCTION

Intraamniotic infection (IAI) and subsequent early-onset neonatal sepsis (EONS) are among the main complications associated with preterm prelabor rupture of membranes (PPROM). Currently used diagnostic tools have been shown to have poor diagnostic performance for IAI. This study aimed to investigate whether the exposure to IAI before delivery is associated with short-term variation of the fetal heart rate in pregnancies with PPROM.

METHODS

Observational cohort study of 678 pregnancies with PPROM, delivering between 24 + 0 and 33 + 6 gestational weeks from 2012 to 2019 in five labor units in Stockholm County, Sweden. Electronic medical records were examined to obtain background and exposure data. For the exposure IAI, we used the later diagnosis of EONS in the offspring as a proxy. EONS is strongly associated to IAI and was considered a better proxy for IAI than the histological diagnosis of acute chorioamnionitis, since acute chorioamnionitis can be observed in the absence of both positive microbiology and biochemical markers for inflammation. Cardiotocography traces were analyzed by a computerized algorithm for short-term variation of the fetal heart rate, which was the main outcome measure.

RESULTS

Twenty-seven pregnancies were categorized as having an IAI, based on the proxy diagnosis of EONS after birth. Fetuses exposed to IAI had significantly lower short-term variation values in the last cardiotocography trace before birth than fetuses who were not exposed (5.25 vs 6.62 ms; unadjusted difference: -1.37, p = 0.009). After adjustment for smoking and diabetes, this difference remained significant. IAI with a later positive blood culture in the neonate (n = 12) showed an even larger absolute difference in STV (-1.65; p = 0.034), with a relative decrease of 23.5%.

CONCLUSION

In pregnancies with PPROM, fetuses exposed to IAI with EONS as a proxy have lower short-term variation of the fetal heart rate than fetuses who are not exposed. Short-term variation might be useful as adjunct surveillance in pregnancies with PPROM.

Novel Biomarkers: Soluble Urokinase-Type Plasminogen Activator Receptor and Procalcitonin- and Histological Chorioamnionitis after Preterm Premature Rupture of Membranes

Fetal inflammatory response syndrome or infection after preterm premature rupture of membranes (PPROM) increases neonatal morbidity in preterm deliveries. Biochemical markers from the amniotic fluid (AF) have been used to evaluate possible intra-amniotic infection during the asymptomatic phase after PPROM. This study aimed to describe whether soluble urokinase-type plasminogen activator receptor (suPAR) or procalcitonin (PCT) from AF or maternal sera could reveal fetal inflammatory response or infection after PPROM. AF and maternal serum samples were collected weekly after PPROM (23+ 0 - 34+ 6 gestational weeks) until delivery from twenty women and two women with possible chorioamnionitis with intact membranes. Levels of suPAR, PCT, interleukin-6 (IL-6), glucose, lactate dehydrogenase (LDH), and bacterial PCR were determined from AF and suPAR and PCT and IL-6 from maternal sera. Fetal infection or inflammation response were determined by the histology of the placenta after delivery. AF glucose was significantly lower and AF LDH higher in the fetal site histologic chorioamnionitis (HCA) group, while AF suPAR concentrations tended to be higher in this group. AF suPAR correlated significantly with AF glucose and LDH. Based on receiver operating characteristic (ROC) analysis, AF glucose had the best predictability for fetal site histological chorioamnionitis. The findings of AF PCT were insignificant considering HCA. AF glucose had the highest accuracy in predicting fetal site histologic chorioamnionitis. AF suPAR may be a promising marker; however, our findings were limited by a small study population.

A systematic review on the use of C-reactive protein in autopsy practice

Postmortem analysis of C-reactive protein (CRP) in autopsies has been extensively researched for its potential utility. This analysis could aid forensic pathologists in screening for and investigating the potential infectious or inflammatory causes of death, thereby guiding appropriate autopsy procedures. To assess the diagnostic accuracy of postmortem CRP analysis in autopsy settings, a thorough electronic literature search was conducted across databases such as PubMed, Scopus, Web of Science, and Cochrane Library. Two independent reviewers screened eligible studies, followed by a methodological quality assessment using the QUADAS-2 checklist. Utilising a random-effects model, hierarchical summary receiver operating characteristic (HSROC) curve analysis and bivariate model meta-analysis were performed to evaluate heterogeneity across studies. Of the 1286 studies initially identified, nine met the eligibility criteria for the final analysis. The pooled sensitivity of postmortem CRP analysis was 0.93 (95% CI, 0.76, 0.98), with a pooled specificity of 0.80 (95% CI, 0.71, 0.87). The prevalence across studies ranged from 0.23 to 0.68, with a median of 0.5. Moderate variability was observed in the heterogeneity assessment across the primary studies. In summary, the study findings indicate that postmortem serum CRP analysis demonstrates high diagnostic accuracy with moderate heterogeneity. Additionally, postmortem CRP testing may be useful as a screening tool in autopsy practice to rule out the likelihood of sepsis.

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.

Maternal biomarkers in predicting neonatal sepsis after preterm premature rupture of membranes in preterm infants

AIM

This retrospective cohort study aimed to assess the utility of maternal C-reactive protein (CRP) and leukocyte levels in predicting neonatal sepsis after preterm premature rupture of membranes (pPROM).

METHODS

We conducted a retrospective cohort study (2009-2021), encompassing preterm infants born ≤29 + 6 weeks of gestation following pPROM. The primary outcome was early-onset neonatal sepsis within the initial 72 h of life.

RESULTS

We analysed data from 706 patients with a median gestational age at pPROM of 25.1 weeks and a median gestational age at birth of 26.4 weeks. Overall survival rate was 86.1%, with 65.7% survival without severe morbidities. These rates were significantly worse in preterm infants with sepsis. Maternal CRP and leukocyte levels correlated significantly with neonatal infection markers and sepsis. However, their predictive values, correlation coefficients, and area under the curve values were generally low. Using maternal CRP ≥2 mg/dL to predict neonatal sepsis yielded a positive predictive value of 18.5%, negative predictive value of 91.5%, AUC of 0.589, 45.5% sensitivity, and 74.5% specificity.

CONCLUSION

Maternal CRP and leukocyte levels were ineffective as a tool for predicting early-onset neonatal sepsis following early pPROM. Consequently, these biomarkers lack the reliability required for clinical decision-making in this context.

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.

Maternal serum amino acid levels as predictors of premature rupture of membranes: A comprehensive analysis

INTRODUCTION

The aim of this study is to investigate the association between altered maternal serum amino acids (AAs) levels and premature rupture of membranes (pPROM) in pregnant women.

METHODS

We conducted a case-control study involving 60 pregnant women diagnosed with pPROM and 60 healthy pregnant women as controls. Amino acid levels were quantified using high-performance liquid chromatography. Receiver operating characteristic (ROC) curve analysis was performed to determine the predictive capability of specific AAs for pPROM.

RESULTS

Our findings revealed that lysine, glycine, and glutamic acid levels were significantly elevated in the pPROM group compared with the control group. Lysine, with a threshold value exceeding 137.90 μmol/L, exhibited the highest predictive accuracy, with an area under the curve (AUC) of 0.796 (p < 0.001), sensitivity of 66.7 %, and specificity of 80.0 %. Glycine, with a cut-off value of >242.48 μmol/L, had an AUC of 0.789 (p < 0.001), sensitivity of 83.3 %, and specificity of 65.0 %. Glutamic acid, at a threshold of 111.40 μmol/L, demonstrated an AUC of 0.787 (p < 0.001), sensitivity of 88.3 %, and specificity of 65.0 %. These AAs could effectively predict the occurrence of pPROM.

CONCLUSION

Elevated blood levels of lysine, glycine, and glutamic acid were found to be associated with pPROM. These AAs serve as potential predictive biomarkers for pPROM, with lysine showing the highest AUC and sensitivity. Identifying such biomarkers may contribute to the development of non-invasive diagnostic tools for pPROM risk assessment, enabling timely interventions and improved maternal and fetal outcomes.

Laboratory markers to identify acute histological chorioamnionitis in febrile parturients undergoing epidural analgesia: a retrospective study

BACKGROUND

This study aimed to investigate the effect of the pathological staging of acute histological chorioamnionitis (HCA) on laboratory indicators and to conduct further studies to reassess the threshold values used by clinicians to identify acute HCA in febrile parturients undergoing epidural analgesia.

METHODS

A retrospective study of febrile mothers receiving epidural analgesia at Nanjing Maternal and Child Health Care Hospital from January 1, 2018 to December 31, 2018. The participants were grouped by the progression of acute HCA, and the laboratory parameters were compared between groups. The ability of C-reactive protein (CRP), neutrophil-lymphocyte ratio (NLR), monocyte-lymphocyte ratio (MLR), and monocyte-leukocyte ratio (M%), alone or in combination, to identify acute HCA in febrile parturients undergoing epidural analgesia was assessed using logistic regression and ROC curves.

RESULTS

The area under the curve (AUC) of the best logistic regression model predicting HCA climbed to 0.706 (CRP + MLR). Maternal CRP, NLR, and MLR significantly and progressively increased with the progression of acute HCA (p < 0.0001). Based on the ROC curves, the following thresholds were selected to define increased laboratory indicators for identifying acute HCA: CRP ≥ 6.90 mg/L, NLR ≥ 11.93, and MLR ≥ 0.57. In addition, the AUC of the best logistic regression model predicting HCA ≥ stage 2 was 0.710, so these inflammatory markers were more precise in predicting HCA ≥ stage 2.

CONCLUSION

Increased CRP (≥ 6.90 mg/L), NLR (≥ 11.93), and MLR (≥ 0.57) may help clinicians to identify early potential acute HCA in febrile parturients receiving epidural analgesia and to monitor progression to optimize clinical treatment options.

TRIAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry on November 24, 2021 ( http://www.chictr.org.cn , ChiCTR2100053554).

Predictive value of serum inflammatory markers for histological chorioamnionitis among women with preterm premature rupture of membranes after undergoing cervical cerclage

PURPOSE

To determine the predictive value of maternal White Blood Cells (WBC), neutrophils, and C-Reactive Protein (CRP) for diagnosing Histological Chorioamnionitis (HCA) among women with Preterm Premature Rupture of Membranes (PPROM) who underwent cervical cerclage.

METHODS

A retrospective cross-sectional study was conducted among women with singleton pregnancy and PPROM, who underwent cervical cerclage during 2018-2020.

RESULTS

A total of 55 eligible women were included in the final analysis, including 36 (61.02%) cases with HCA and 19 (38.98%) without HCA. Women with HCA had higher WBC count (12.31 ± 2.80) × 109/L and neutrophil count (9.67 ± 2.90)×109/L than those without HCA (10.35 ± 2.53) × 109/L and 7.82 ± 2.82 × 109/L, respectively) (both p < 0.05). The cut-off value of WBC count at 10.15×109/L was found to be the most effective in identifying HCA, with an Area Under Curve (AUC) of 0.707 (95% CI: 0.56-0.86; p = 0.012), sensitivity of 86.11%, specificity of 57.90%, Positive Predictive Value (PPV) of 79.49%, Negative Predictive Value (NPV) of 68.75%, and Youden index of 0.44. The combination of WBC + neutrophil had a slightly higher (AUC = 0.711, 95% CI: 0.57-0.86; p = 0.011), specificity (68.42%), and PPV (81.25%), but lower sensitivity (72.22%), than the WBC count alone. A cut-off value of neutrophil at 7.46 × 109/L was effective in identifying HCA, with an AUC of 0.689 (95% CI: 0.53-0.84; p = 0.022).

DISCUSSION

Combination use of WBC+neutrophil was found to be the most accurate predictor of HCA among women with PPROM after surgery of cervical cerclage.

FIGO good practice recommendations for preterm labor and preterm prelabor rupture of membranes: Prep-for-Labor triage to minimize risks and maximize favorable outcomes

Preterm labor occurs in around 10% of pregnancies worldwide. Once diagnosed, significant efforts must be made to reduce the likelihood of morbidity and mortality associated with preterm birth. In high-resource settings, access to hospitals with a neonatal intensive care unit (NICU) is readily available, whereas access to NICU care is limited in low- and middle-income countries (LMICs) and many rural settings. Use of FIGO's Prep-for-Labor triage method rapidly identifies low- and high-risk patients with preterm labor to enable clinicians to decide whether the patient can be managed on site or if transfer to a level II-IV facility is needed. The management steps described in this paper aim to minimize the morbidity and mortality associated with preterm labor and in the setting of preterm labor with preterm premature rupture of membranes (PPROM). The methods for accurate diagnosis of PPROM and chorioamnionitis are described. When the risk of preterm birth is high, antenatal corticosteroids should be administered for lung maturation combined with limited tocolysis for 48 hours to permit the corticosteroid course to be completed. Magnesium sulfate is also administered for fetal neuroprotection. Implementation of FIGO's Prep-for-Labor triage method in an LMIC setting will help improve maternal and neonatal outcomes.

Amniotic fluid interleukin-6 and neutrophil gelatinase-associated lipocalin for predicting fetal inflammatory response syndrome based on histological chorioamnionitis and funisitis

OBJECTIVE

We aimed to analyze the predictive efficacy of amniotic fluid interleukin-6 (IL-6) and neutrophil gelatinase-associated lipocalin (NGAL) for fetal inflammatory response syndrome (FIRS)-related infection.

MATERIALS AND METHODS

We included singleton pregnancies classified into FIRS and non-FIRS groups. FIRS was defined as histologic chorioamnionitis and funisitis. Amniotic fluid samples were collected during vaginal delivery (VD) or cesarean section (CS). We compared amniotic fluid IL-6 and NGAL levels between the groups.

RESULTS

Forty-six pregnancies were analyzed and classified into 20 (43.5%) FIRS and 26 (56.5%) non-FIRS pregnancies. We observed significant differences in amniotic fluid IL-6 and NGAL. Amniotic fluid collection significantly influenced NGAL levels (p < 0.001). The area under the concentration-time curve (AUC), with optimal cutoff values, for amniotic fluid IL-6 and NGAL (VD and CS) levels was 0.948 (11,344 pg/mL), 0.800 (1180 ng/mL), and 0.946 (708 ng/mL), respectively.

CONCLUSION

Amniotic fluid IL-6 and NGAL levels showed equivalent predictive ability for FIRS-related infection.

Predicting chorioamnionitis in patients with preterm premature rupture of membranes using inflammatory indexes: a retrospective study

OBJECTIVE

The prognosis of preterm premature rupture of membranes (PPROM) combined with chorioamnionitis is often unsatisfactory for both mother and newborn. Although tragic outcomes can be avoided if treated early, no effective prediction method for decision-making is available currently. This study aimed to establish an effective method with maternal inflammation indexes to predict preterm premature rupture of membranes with concomitant chorioamnionitis.

MATERIALS AND METHODS

This retrospective study examined the data of 206 singleton PPROM cases and 60 normal full-term cases. The PPROM cases included 93 cases of PPROM with chorioamnionitis and 113 cases of PPROM without chorioamnionitis based on clinical manifestations, laboratory examinations, and histopathological diagnosis. Normal full-term cases were included as the control group. Peripheral blood levels of selected inflammatory indicators were observed 12 h after fetal membrane rupture. Associations between selected inflammatory indicators and chorioamnionitis diagnosis were analyzed.

RESULTS

Selected factors except for procalcitonin predicted chorioamnionitis in PPROM patients. Combined results of C-reactive protein and white blood cell (WBC) count showed best predictive ability with area under curve, sensitivity, and specificity of 0.702, 60.22%, and 76.11%, respectively. Furthermore including Interleukine-6 and neutrophil count provided similar predictive results.

CONCLUSIONS

The best predictive factor combinations for PPROM-CAM were C-reactive protein and white blood cell count. Results of this study provide a useful clinical reference for PPROM-CAM and may improve maternal and infant prognostic outcomes.

The role of upper and lower genital tract microbiota alterations in term chorionamnionitis: A prospective study

Objective

This study aimed to compare the dynamics of lower and upper genital tract microbiota in normal term pregnancy, histological chorioamnionitis (HCA), and clinical chorioamnionitis (CCA) patients to provide a reference for the diagnosis and treatment of chorioamnionitis (CAM) patients.

Methods

We prospectively collected vaginal and cervical secretions, as well as placenta tissues, fetal membranes, and amniotic fluid from normal-term pregnant women, HCA and CCA patients. Then, we performed genomic DNA extraction and PCR amplification for all samples. The eligible samples were analyzed by 16S ribosomal RNA (16S rRNA) sequencing. Additionally, all placenta tissues were histopathologically examined, and neonatal pharyngeal swabs and placenta tissues from the HCA and CCA groups were subjected to microbial culture.

Results

A total of 85 term pregnant women were enrolled in this study, including 34 in the normal group (N), 37 in the HCA group, and 14 in the CCA group. A total of 171 qualified samples were analyzed by 16S rRNA sequencing. The results suggested that the cervical microbiota was highly similar to the vaginal microbiota in normal term parturients, with Lactobacillus as the dominant bacterium. Moreover, there was no difference in the alpha and beta diversity of vaginal microbiota between the N, HCA, and CCA groups at the genus level. Besides, no significant differences were detected in cervical microbiome among the three groups. Regarding intrauterine microorganisms, the N and HCA groups had similar microbial composition but were different from the CCA group. No microbe was detected in the placental tissue of normal term parturients, while some microorganisms were found in the intrauterine amniotic fluid and fetal membrane samples. Regardless of cultivation or 16S rRNA sequencing, an extremely low microbial positive rate was detected in HCA and CCA intrauterine samples. Compared to the normal group, Lactobacillus was significantly reduced in the CCA group intrauterine, and Ureaplasma and Enterococcus increased with no statistically significant.

Conclusion

The N, HCA and CCA groups had similar composition of vaginal and cervical microflora. Some normal-term pregnant women can harbor non-pathogenic microbiota in the uterine cavity. Sterile inflammation is more frequent than microbial-associated inflammation in term HCA and CCA parturients.

Determinants for perinatal adverse outcomes among pregnant women with preterm premature rupture of membrane: A prospective cohort study

Background

One of the most critical functions of the fetal membranes is to remain intact until the onset of labor to maintain the protective intrauterine fluid environment. In most pregnancies, spontaneous rupture usually occurs near the end of the first stage of labor. Preterm premature membrane rupture (PROM) occurs when the fetal membrane ruptures before 37 weeks of pregnancy, and it contributes to adverse maternal, fetal, and neonatal outcomes. Therefore, this study aimed to determine the association of determinant factors with adverse perinatal outcomes.

Methods

A prospective cohort study was conducted on pregnant women with preterm premature membrane rupture (n = 160) attending the teaching hospitals at Addis Ababa University. Socio-demographic and obstetric risk factors with adverse perinatal outcomes include the 5th minute Apgar score, neonatal intensive care unit (NICU) admission, early-onset neonatal sepsis (EONS), respiratory distress syndrome (RDS), perinatal mortality, Chorioamnionitis, and placental abruption were assessed. SPSS version 24, t-test, χ ² test, and logistic regression analysis were used. P-values <0.25 in the bivariate and p < 0.05 in the multiple logistic regression were considered statistically significant.

Results

The preterm (PROM) rate was 2.2% with perinatal mortality rate of 206/1,000. Gestational age (GA) at delivery was the determinate for low Apgar score at the 5th minute (AOR: 7.23; 95% CI, 1.10, 47.6; p = 0.04). Unable to use steroid (AOR: 8.23; 95% CI, 1.83, 37.0; p = 0.000), GA at membrane rupture (AOR: 4.61; 95% CI, 1.98, 31.8; p = 0.000) and delivery (AOR: 4.32; 95% CI, 1.99, 30.9; p = 0.000) were determinates for NICU admission. EONS was significantly affected by GA at membrane rupture (AOR: 5.9; 95% CI, 1.01, 37.0; p = 0.04). Placental abruption was significantly affected by GA at delivery (AOR: 7.52; 95% CI, 1.15, 48.96; p = 0.04).

Conclusion

GA at membrane rupture and delivery was the most critical predictors of adverse perinatal outcomes. Local guidelines on the approach and preterm PROM outcome management need to be prepared.

Directive clinique no 430 : Diagnostic et prise en charge de la rupture prématurée des membranes avant terme

OBJECTIF

Fournir des directives claires et concises pour le diagnostic et la prise en charge de la rupture prématurée des membranes avant terme (RPMAT).

POPULATION CIBLE

Toute patiente manifestant une rupture prématurée des membranes avant 37 semaines d'aménorrhée. BéNéFICES, RISQUES ET COûTS: La présente directive clinique vise à fournir les premières recommandations générales canadiennes sur la prise en charge de la rupture des membranes avant terme. Elle repose sur un examen complet et à jour des données probantes sur le diagnostic de la rupture et sur la prise en charge, le bon moment et les modes d'accouchement. DONNéES PROBANTES: Des recherches ont été effectuées dans PubMed-Medline et Cochrane en 2021 en utilisant les termes suivants : preterm premature rupture of membranes, PPROM, chorioamnionitis, Nitrazine test, ferning, commercial tests, PAMG-1, IGFBP-1 test, ultrasonography, PPROM/antenatal corticosteroids, PPROM/Magnesium sulphate, PPROM/antibiotic treatment, PPROM/tocolysis, PPROM/preterm labour, PPROM/neonatal outcomes, PPROM/mortality, PPROM/outpatient/inpatient, PPROM/cerclage, previable PPROM. Les articles retenus sont des essais cliniques randomisés, des méta-analyses, des revues systématiques, des directives cliniques et des études observationnelles. D'autres publications pertinentes ont été sélectionnées à partir des notices bibliographiques de ces articles. Seuls les articles en anglais ont été examinés. MéTHODES DE VALIDATION: Les auteurs ont évalué la qualité des données probantes et la force des recommandations en utilisant le cadre méthodologique GRADE (Grading of Recommendations, Assessment, Development, and Evaluation). Voir l'annexe A (tableau A1 pour les définitions et tableau A2 pour l'interprétation des recommandations fortes et faibles). PROFESSIONNELS CONCERNéS: Tous les fournisseurs de soins de santé prénatale ou périnatale. DÉCLARATIONS SOMMAIRES: RECOMMANDATIONS.

Guideline No. 430: Diagnosis and management of preterm prelabour rupture of membranes

OBJECTIVE

To provide clear and concise guidelines for the diagnosis and management of preterm prelabour rupture of membranes (PPROM) TARGET POPULATION: All patients with PPROM <37 weeks gestation BENEFITS, HARMS, AND COSTS: This guideline aims to provide the first Canadian general guideline on the management of preterm membrane rupture. It includes a comprehensive and up-to-date review of the evidence on the diagnosis, management, timing and method of delivery.

EVIDENCE

The following search terms were entered into PubMed/Medline and Cochrane in 2021: preterm premature rupture of membranes, PPROM, chorioamnionitis, Nitrazine test, ferning, commercial tests, placental alpha microglobulin-1 (PAMG-1) test, insulin-like growth factor-binding protein-1 (IGFBP-1) test, ultrasonography, PPROM/antenatal corticosteroids, PPROM/Magnesium sulphate, PPROM/ antibiotic treatment, PPROM/tocolysis, PPROM/preterm labour, PPROM/Neonatal outcomes, PPROM/mortality, PPROM/outpatient/inpatient, PPROM/cerclage, previable PPROM. Articles included were randomized controlled trials, meta-analyses, systematic reviews, guidelines, and observational studies. Additional publications were identified from the bibliographies of these articles. Only English-language articles were reviewed.

VALIDATION METHODS

The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See Appendix A (Tables A1 for definitions and A2 for interpretations of strong and weak recommendations).

INTENDED AUDIENCE

All prenatal and perinatal health care providers.

SUMMARY STATEMENTS

RECOMMENDATIONS.

Screening and diagnosis of women for chorioamnionitis: An integrative literature review

OBJECTIVE

This integrative literature review provides an overview of current best research evidence on the screening and diagnosis of women for chorioamnionitis, as no current review has been conducted. An overview of best practices on screening and diagnosis of women for chorioamnionitis can assist midwives with an accurate diagnosis, allowing for early referral and adequate management of this infection.

DESIGN

An integrative literature review was conducted using a systematic electronic literature search through EBSCOhost (CINAHL with Full Text, e-Book Collection, Health Source: Nursing/Academic Edition, MEDLINE, Open Dissertations and PsycINFO), Cochrane Online, PubMed, Scopus, followed by a manual search for grey literature using Google and a citation search. Guidelines, research studies, and reports in English related to chorioamnionitis from 2008 up until 2020 were included in the study.

FINDINGS

After critical appraisal, using the Joanna Briggs Institution's checklists, Evaluation Tool for Quantitative Research Studies' tool and the Appraisal of Guidelines for Research & Evaluation instrument, 31 articles were included. More than half (64%) of the literature included ranked on the three highest levels of evidence (Level I, II and III). Data extracted regarding screening and diagnosis of women for chorioamnionitis was synthesised into four themes, namely: screening by clinical signs and symptoms, screening by causative factors of chorioamnionitis, screening of obstetric history, and essential biomarkers to diagnose chorioamnionitis.

KEY CONCLUSIONS

Screening and recording of any risk factors will assist midwives in providing tailored health education to possibly prevent causative factors that could lead to chorioamnionitis. Although matrix-metalloproteinase-8 (MMP-8) seems the most suitable test to use for screening, an accurate diagnosis of chorioamnionitis requires a combination of screening methods and tests, such as clinical signs and symptoms, maternal biomarkers, amniotic fluid testing and histology. Screening for chorioamnionitis, particularly the parameters for maternal fever as a clinical symptom of chorioamnionitis, contributing factors and microbes responsible for chorioamnionitis, the usability of MMP-8 and the development of rapid, inexpensive, easy-to-use techniques for screening and diagnosis of chorioamnionitis, warrants further research.

IMPLICATIONS FOR PRACTICE

Findings can be used by midwives in the screening and diagnosis of women for chorioamnionitis which allows for early referral and adequate management before maternal and neonatal complications arise.

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.

Histological severity of maternal and fetal inflammation is correlated with the prevalence of maternal clinical signs

AIM

To evaluate whether there is a stepwise increase in the prevalence of maternal clinical signs according to the severity of histological inflammation in the chorioamniotic membranes, placenta, and umbilical cord in preterm deliveries.

METHODS

This retrospective study, conducted between January 2007 and May 2017, included patients with preterm delivery between 22 and 33 weeks. The histological findings of maternal/fetal inflammatory responses were staged and graded according to the Amsterdam Placental Workshop Group consensus statement. Correlations between the histological severity of maternal/fetal inflammatory responses and the prevalence of clinical chorioamnionitis and clinical signs were evaluated using the Cochran-Armitage trend test.

RESULTS

A total of 138 patients were included. The stage and grade of the maternal inflammatory response were correlated with earlier gestational weeks at delivery and lighter birth weight. The prevalence of clinical chorioamnionitis was significantly correlated with a higher stage and grade of the maternal inflammatory response (Gibbs/Lencki criteria: 15.8%/15.8% in Stage 3, 16.3%/14% in Grade 2). No significant correlations were observed between gestational weeks at delivery and birth weight and stage/grade of fetal inflammatory response. The prevalence of clinical chorioamnionitis was significantly correlated with higher stage and grade of fetal inflammatory response (Gibbs/Lencki criteria: 25%/25% in Stage 3 and 29.4%/29.4% in Grade 2).

CONCLUSION

Correlations exist between the severity of histological maternal/fetal inflammatory responses and the prevalence of clinical chorioamnionitis and positive maternal clinical signs in preterm deliveries. However, the prevalence of clinical chorioamnionitis was 20%-30% even in the most severe fetal inflammatory responses.

Chorioamnionitis and neonatal outcomes

Chorioamnionitis or intrauterine inflammation is a frequent cause of preterm birth. Chorioamnionitis can affect almost every organ of the developing fetus. Multiple microbes have been implicated to cause chorioamnionitis, but "sterile" inflammation appears to be more common. Eradication of microorganisms has not been shown to prevent the morbidity and mortality associated with chorioamnionitis as inflammatory mediators account for continued fetal and maternal injury. Mounting evidence now supports the concept that the ensuing neonatal immune dysfunction reflects the effects of inflammation on immune programming during critical developmental windows, leading to chronic inflammatory disorders as well as vulnerability to infection after birth. A better understanding of microbiome alterations and inflammatory dysregulation may help develop better treatment strategies for infants born to mothers with chorioamnionitis.

A Retrospective Study of the Proportion of Women at High and Low Risk of Intrauterine Infection Meeting Sepsis Criteria

The Surviving Sepsis Campaign recently recommended that qSOFA not be used as a single parameter for identification of sepsis. Thus, we evaluated the efficacy of SIRS and qSOFA scores in identifying intrauterine infection. This case–control study evaluates SIRS and qSOFA criteria fulfillment in preterm premature rupture of membranes (n = 453)—at high infection risk—versus elective cesarean—at low infection risk (n = 2004); secondary outcomes included intrauterine infection and positive culture rates. At admission, 14.8% of the study group and 4.6% of control met SIRS criteria (p = 0.001), as did 12.5% and 5.5% on post-operation day (POD) 1 (p = 0.001), with no significant differences on POD 0 or 2. Medical records did not suffice for qSOFA calculation. In the study group, more cultures (29.8% versus 1.9%—cervix; 27.4% versus 1.1%—placenta; 7.5% versus 1.7%—blood; p = 0.001—all differences) and positive cultures (5.5% versus 3.0%—urine—p = 0.008; 4.2% versus 0.2%—cervix—p = 0.001; 7.3% versus 0.0%—placenta—p = 0.001; 0.9% versus 0.1%—blood—p = 0.008) were obtained. Overall, 10.6% of the study group and 0.4% of control met the intrauterine infection criteria (p = 0.001). Though a significant difference was noted in SIRS criteria fulfillment in the study group versus control, there was considerable between-group overlap, questioning the utility of SIRS in intrauterine infection diagnosis. Furthermore, the qSOFA scores could not be assessed.

Reference values for C-reactive protein and procalcitonin at term pregnancy and in the early postnatal period

BACKGROUND

Early recognition of sepsis and prompt treatment improves patient outcome. C-reactive protein is a sensitive marker for tissue damage and inflammation, but procalcitonin has greater specificity for bacterial infection. Limited research exists regarding the use of C-reactive protein and procalcitonin at term pregnancy and the immediate postpartum period.

AIM

This study sought to define reference values for C-reactive protein and procalcitonin at term and the early postnatal period.

METHODS

A prospective cross-sectional study was performed in a university teaching hospital. Venous blood was collected from healthy women (n = 196), aged between 19 and 45 years with an uncomplicated singleton pregnancy, at term (37-40 weeks' gestation) and on day 1 and day 3 postpartum for the measurement of C-reactive protein and procalcitonin.

RESULTS

The reference population comprised of 189 participants: term pregnancy (n = 51), postpartum day 1 vaginal delivery (n = 70) and caesarean section (n = 38) and day 3 (caesarean section, n = 30). The maximum procalcitonin value at term pregnancy was 0.1 μg/L. On day 1 postpartum, 90% and 86.8% of procalcitonin results for vaginal delivery and caesarean section, respectively, were below the decision-threshold of 0.25 μg/L. The specificity of procalcitonin to rule out infection in the reference population was 91.5%.

CONCLUSIONS

Reference values for procalcitonin were established in a well-characterized population of healthy pregnant women at term and immediately postpartum. The variability of C-reactive protein limits its clinical utility in the assessment of systemic sepsis. Application of the procalcitonin cut-off of 0.25 μg/L in this population will be a valuable adjunct to clinicians ruling out infection in pregnancy and postpartum.

Pregnancy-specific reference intervals for C-reactive protein improve diagnostic accuracy for infection: A longitudinal study

BACKGROUND AND AIMS

Infections are a major cause of maternal mortality. C-reactive protein (CRP), a commonly-used inflammatory marker, is widely used to inform diagnosis, but the upper limit of normal in pregnancy is uncertain. We have defined trimester-specific reference intervals for CRP and evaluated their diagnostic accuracy for infection.

MATERIALS AND METHODS

Development cohort: longitudinal study of pregnant women to determine 95% reference intervals. Evaluation cohort: diagnostic accuracy study to evaluate these intervals in 50 women with suspected intrauterine infection.

RESULTS

In these 322 healthy pregnant women, CRP was substantially higher than in most non-pregnant populations. CRP was similar in each trimester, with an upper reference limit of 19 mg/L. CRP increased linearly with body mass index (p < 0.0001). The sensitivity and specificity of CRP for diagnosing chorioamnionitis were 73% and 86%, respectively. The overall diagnostic accuracy using the pregnancy-specific reference interval was significantly better than that of the existing standard (p = 0.03).

CONCLUSIONS

CRP is a widely-used clinical tool in pregnancy, and a pregnancy-specific reference interval should be used to optimise diagnostic accuracy. Chorioamnionitis was used as an example of a localised infection with well-defined outcomes, but pregnancy-specific RIs for CRP should be considered in any clinical setting including pregnant women.