Methods for the diagnosis of rupture of the fetal membranes in equivocal cases: a systematic review

Uncertain prelabor rupture of membranes at term and associated delivery outcomes

OBJECTIVE

To determine whether equivocal prelabor rupture of membranes (PROM) cases are associated with adverse outcomes.

METHODS

A retrospective study was conducted in a tertiary medical center between July 2012 and March 2022. The cohort comprised all women diagnosed with term PROM (≥37 gestational weeks), divided into two groups. (1) Certain PROM-suggestive history of a watery vaginal discharge confirmed by visualization of fluid leaking from the cervix or pooling in the vagina on speculum examination. (2) Uncertain PROM-suggestive history of a watery vaginal discharge not supported by speculum examination. All patients were hospitalized and gave birth spontaneously or following either expectant management for up to 24 h from PROM or induction. The primary outcome measure was cesarean delivery (CD) rate. Secondary outcome measures were adverse maternal/neonatal events.

RESULTS

Of the 2012 women included in the study, 1750 had certain PROM and 262 uncertain PROM. CD rate was 5.8% in the certain PROM group and 8.8% in the uncertain PROM group; the difference was not statistically significant (P = 0.074). There was a significant between-group difference in the rate of CD due to failed induction on univariate analysis (0.69% vs 2.67%, respectively, P = 0.007), but it was not maintained on multivariate logistic regression (odds ratio 0.37, 95% confidence interval: 0.12-1.17). Other maternal and neonatal outcomes were similar in the two groups.

CONCLUSION

Our findings indicate that following the same management guidelines for equivocal cases of ruptured membranes as for confirmed cases of term PROM did not compromise maternal or fetal outcomes.

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.

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.

Current and Emerging Strategies for Prediction and Diagnosis of Prelabour Rupture of the Membranes: A Narrative Review

Prelabour rupture of membranes (PROM) refers to the disruption of foetal membranes before the onset of labour, resulting in the leakage of amniotic fluid. PROM complicates 3% and 8% of preterm and term pregnancies, respectively. Accurate and timely diagnosis is crucial for effective management to prevent adverse maternal- and foetal-outcomes. The diagnosis of equivocal PROM cases with traditional methods often becomes challenging in current obstetrics practice; therefore, various novel biochemical markers have emerged as promising diagnostic tools. This narrative review is sought to review the published data to understand the current and emerging trends in diagnostic modalities in term and preterm pregnancies complicated with PROM and the potential role of various markers for predicting preterm PROM (pPROM) and chorioamnionitis in women with pPROM.

[Diagnosis of rupture of fetal membranes: CNGOF Preterm Premature Rupture of Membranes Guidelines]

OBJECTIVE

To describe clinical and paraclinical tests diagnosing rupture of fetal membranes (ROM).

METHODS

Bibliographic search over the period 1980-2017 considering articles in French and English as well as guidelines from national obstetrical societies.

RESULTS

Typical amniotic fluid leakage occurs in ¾ of cases. In this situation, no additional test is required (Professional consensus). For ambiguous cases, a speculum examination can demonstrate pooling of amniotic fluid but suspicion can persist in 50% of cases (evidence level IV). In this context, we recommend to consider performing an IGFBP-1 or PAMG-1 test of vaginal fluid (evidence level III). Ability of these tests to reduce maternal or neonatal morbidity has never been demonstrated (Professional consensus). An isolated positive test should be considered cautiously as false positive does exist (Professional consensus).

CONCLUSION

Symptoms suggestive of ROM and speculum examination demonstrating pooling of amniotic fluid are sufficient to diagnose ROM. If pooling is not observed, we recommend to consider performing an IGFBP-1 or PAMG-1 test of vaginal fluid.

Use of beta subunit of human chorionic gonadotropin assay as a diagnostic tool for prelabor rupture of membranes

PURPOSE

The study aimed at assessment of the accuracy of the β-hCG test in vaginal washing fluid for diagnosis of prelabor rupture of membranes (PROM).

PATIENTS AND METHODS

Two groups of pregnant women from 17 to 38 weeks of gestation were recruited. The first group (PROM group) included 50 pregnant women with unequivocal PROM. The other group included 50 pregnant women with intact membranes. A sterile speculum examination was performed. If less than 5 cc was collected or no fluid found, 10 cc sterile saline was sprinkled on the vaginal wall and 5 cc were recollected in a sterile syringe. Two drops of collected fluid were used for qualitative testing of β-hCG. The remaining fluid was used for quantitative assessment of β-hCG.

RESULTS

The quantitative β-hCG test results were significantly higher in PROM group (median and range: 138.5 (23-475) versus 13 (1-55); the difference in medians and 95% CI: 105 (91-166); p value: <.001). The qualitative β-hCG test was positive in 42/50 (84%) of the PROM group, while it was negative in 50/50 (100%) of the intact membranes group. Areas under receiver operating characteristics (AUC) for both the quantitative and qualitative β-hCG tests were high (0.97, 95% CI: 0.91-0.99, p value: <.001 and .92, 95% CI: 0.84-0.96, p value: <.001, respectively). The suggested cut-off of β-hCG for the quantitative test was 32 mIU/ml. The sensitivity of quantitative and qualitative tests are: 94, 95% CI: 83.5-98.7% and 84, 95% CI: 70.9-92.8%, respectively. The specificity of quantitative and qualitative tests are: 94, 95% CI: 83.5-98.7% and 100, 95% CI: 92.9-100%, respectively.

CONCLUSION

β-hCG test (either quantitative or qualitative) in vaginal washing fluid can be used in the diagnosis of PROM in both preterm and term cases.

Women's expectations and experiences of rupture of membranes and views of the potential use of reagent pads for detecting amniotic fluid

AIMS

To explore first-time mothers' expectations and experiences regarding rupture of membranes at term and their views on the potential use of reagent pads that detect amniotic fluid.

BACKGROUND

There is little information available on women's experiences of spontaneous rupture of membranes, or interest in using methods to confirm rupture of membranes (e.g. reagent pads).

DESIGN

Descriptive qualitative study, using focus groups and telephone interviews with women during pregnancy and after the birth of their first baby. Thematic analysis was undertaken to analyse women's responses.

METHODS

Ethics committee approval was obtained. Twenty-five women participated in the study of whom 13 contributed both during pregnancy and postpartum between October 2015-March 2016.

FINDINGS

Three overarching themes were identified from the data from women's expectations and experiences: uncertainty in how, when and where membranes may rupture; information which was felt to be limited and confirmation of rupture of membranes. The potential use of reagent pads met with varied responses.

CONCLUSION

Women were interested in having facts and figures regarding rupture of membranes, such as characteristics of liquor; volume and probability of membranes rupturing spontaneously at term. Use of a pad as a means of confirmation was viewed as helpful, although the potential for increasing anxiety was raised.

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.

ADAMTS4 and Oxidative/Antioxidative Status in Preterm Premature Rupture of Membranes

AIM

To determine the function of a disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS4), total oxidant status (TOS), total antioxidant status (TAS), and aryl esterase (ARES) in preterm premature rupture of membranes (PPROM) and to investigate the association with premature rupture of membranes (PROMs).

MATERIAL AND METHODS

58 pregnant women were included in this prospective study which comprised 29 PPROM patients as the study group and 29 patients, having healthy amniotic membranes, as the control group. ADAMTS4, TAS, TOS, and ARES levels were studied in the amniotic membrane homogenates of the patients.

RESULTS

ADAMTS4, TAS TOS, and ARES levels of amniotic membrane lysates were significantly different between PPROM and control groups (p < 0.001, p < 0.001, p = 0.008 and p = 0.002, respectively). Increased amniotic membrane ADAMTS4 (OR: 1.051 95% CI 1.006-1.098, p = 0.024) and TOS (OR: 12.777 95% CI 1.595-102.323, p = 0.016) were found to be significantly associated with the increased risk of PPROM.

CONCLUSION

ADAMTS4, TOS, and ARES levels were higher and TAS level was lower in PPROM patients than the normal healthy control group which had healthy amniotic membranes at term. As a result, ADAMTS4 may have a role in the pathogenesis by causing increased oxidative and inflammatory environment in PPROM.

Aspartate aminotransferase and free thyroid hormones in vaginal washing fluid as markers for preterm pre-labor rupture of membranes

AIM

To evaluate the diagnostic value of vaginal fluid aspartate aminotransferase (AST), free triiodothyronine (T3) and free thyroxine (T4 ) in women with preterm pre-labor rupture of membranes (PPROM).

METHODS

A case-control study was carried out of 100 women: 50 with PPROM (study group) and 50 age-, gestational age- and weight-matched women with intact membranes (control group). All women underwent sterile speculum vaginal examination. The vaginal posterior fornix was irrigated and the retrieved fluid was sent for AST, free T3 and free T4 assays.

RESULTS

Median vaginal fluid free T3, free T4 and AST were significantly higher in the PPROM group compared with the control group, with vaginal fluid free T4 having the largest area under the curve on receiver operating characteristic curve analysis (P<0.001). Sensitivity, specificity, positive and negative predictive values for free T3 (cut-off, 1.06 pg/mL) were 88%, 70%, 74.6% and 85.4%, respectively, while those for free T4 (cut-off 0.063 ng/dL) were 86%, 72%, 75.4% and 83.7%, and those for AST (4.5 IU/L) were 56%, 70%, 65.1% and 61.4%, respectively. Vaginal fluid AST had less diagnostic accuracy when compared with either free T3 or free T4.

CONCLUSIONS

Vaginal fluid AST, free T3 and free T4 seem to be useful and simple markers in diagnosis of PPROM.

Placental alpha-microglobulin-1 and combined traditional diagnostic test: a cost-benefit analysis

OBJECTIVE

We sought to evaluate if the placental alpha-microglobulin (PAMG)-1 test vs the combined traditional diagnostic test (CTDT) of pooling, nitrazine, and ferning would be a cost-beneficial screening strategy in the setting of potential preterm premature rupture of membranes.

STUDY DESIGN

A decision analysis model was used to estimate the economic impact of PAMG-1 test vs the CTDT on preterm delivery costs from a societal perspective. Our primary outcome was the annual net cost-benefit per person tested. Baseline probabilities and costs assumptions were derived from published literature. We conducted sensitivity analyses using both deterministic and probabilistic models. Cost estimates reflect 2013 US dollars.

RESULTS

Annual net benefit from PAMG-1 was $20,014 per person tested, while CTDT had a net benefit of $15,757 per person tested. If the probability of rupture is <38%, PAMG-1 will be cost-beneficial with an annual net benefit of $16,000-37,000 per person tested, while CTDT will have an annual net benefit of $16,000-19,500 per person tested. If the probability of rupture is >38%, CTDT is more cost-beneficial. Monte Carlo simulations of 1 million trials selected PAMG-1 as the optimal strategy with a frequency of 89%, while CTDT was only selected as the optimal strategy with a frequency of 11%. Sensitivity analyses were robust.

CONCLUSION

Our cost-benefit analysis provides the economic evidence for the adoption of PAMG-1 in diagnosing preterm premature rupture of membranes in uncertain presentations and when CTDT is equivocal at 34 to <37 weeks' gestation.

Meta-analysis of studies on biochemical marker tests for the diagnosis of premature rupture of membranes: comparison of performance indexes

Background

Premature rupture of the membranes (PROM) is most commonly diagnosed using physical examination; however, accurate decision making in ambiguous cases is a major challenge in current obstetric practice. As this may influence a woman’s subsequent management, a number of tests designed to assist with confirming a diagnosis of PROM are commercially available. This study sought to evaluate the published data for the accuracy of two amniotic fluid-specific biomarker tests for PROM: insulin-like growth factor binding protein-1 (IGFBP-1 – Actim® PROM) and placental alpha microglobulin-1 (PAMG-1 – AmniSure®).

Methods

Main analysis included all PubMed referenced studies related to Actim® PROM and AmniSure® with available data to extract performance rates. To compare accuracy, a comparison of pooled indexes of both rapid tests was performed. Studies in which both tests were used in the same clinical population were also analysed. Membrane status, whether it was known or a suspected rupture, and inclusion or not of women with bleeding, were considered.

Results

All the available studies published in PubMed up to April 2013 were reviewed. Data were retrieved from 17 studies; 10 for Actim® PROM (n = 1066), four for AmniSure® (n = 1081) and three studies in which both biomarker tests were compared directly. The pooled analysis found that the specificity and positive predictive value were significantly higher for AmniSure® compared with Actim® PROM. However, when 762 and 1385 women with known or suspected rupture of membranes, respectively, were evaluated, AmniSure® only remained significantly superior in the latter group. Furthermore, when the two tests were compared directly in the same study no statistically significant differences were observed. Remarkably, women with a history or evidence of bleeding were excluded in all four studies for AmniSure®, in two Actim® PROM studies and in two of the three studies reporting on both tests.

Conclusions

No differences were observed in the performance of the two tests in studies where they were used under the same clinical conditions or in women with known membrane status. Although AmniSure® performed better in suspected cases of PROM, this may need further analysis as exclusion of bleeding may not be representative of the real clinical presentation of women with suspected PROM.

[Rupture of membranes: pathophysiology, diagnosis, consequences and management]

Rupture of membranes (ROM) depends on mechanical stretch, extracellular matrix components imbalance and increased apoptosis. It occurs in 2 to 3% of all pregnancies before 37 weeks' gestation (WG) and in up to 10% at term. Main consequences are labor induction and risk of maternal-fetal infection. ROM is associated with one third of preterm births and about 20% of perinatal mortality. This review deals with recent knowledge concerning ROM including diagnosis and management. In many cases, ROM is easily identified by clinical examination. In other cases, the use of vaginal pH appears to be less efficient than the use of immunochromatographic strips based on IGFBP-1 or PAMG-1 detection. Before 34WG, conservative management consists in in utero transfer, antibioprophylaxis and corticosteroids. After 37WG, delivery is the most appropriate option. Between 34 and 37WG, recent studies demonstrate that induction of labour does not improve pregnancy outcomes. Therefore, expectant management can be the first option between 34 and 37WG when no active infection is suspected especially in case of unfavourable cervix.