Prelabour rupture of membranes: overview of diagnostic methods

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.

Further Evidence that an Episode of Premature Labor Is a Pathologic State: Involvement of the Insulin-Like Growth Factor System

INTRODUCTION

Approximately 47% of women with an episode of preterm labor deliver at term; however, their infants are at greater risk of being small for gestational age and for neurodevelopmental disorders. In these cases, a pathologic insult may disrupt the homeostatic responses sustaining pregnancy. We tested the hypothesis of an involvement of components of the insulin-like growth factor (IGF) system.

METHODS

This is a cross-sectional study in which maternal plasma concentrations of pregnancy-associated plasma protease (PAPP)-A, PAPP-A2, insulin-like growth factor-binding protein 1 (IGFBP-1), and IGFBP-4 were determined in the following groups of women: (1) no episodes of preterm labor, term delivery (controls, n = 100); (2) episode of preterm labor, term delivery (n = 50); (3) episode of preterm labor, preterm delivery (n = 100); (4) pregnant women at term not in labor (n = 61); and (5) pregnant women at term in labor (n = 61). Pairwise differences in maternal plasma concentrations of PAPP-A, PAPP-A2, IGFBP-1, and IGFBP-4 among study groups were assessed by fitting linear models on log-transformed data and included adjustment for relevant covariates. Significance of the group coefficient in the linear models was assessed via t-scores, with p < 0.05 deemed a significant result.

RESULTS

Compared to controls, (1) women with an episode of premature labor, regardless of a preterm or a term delivery, had higher mean plasma concentrations of PAPP-A2 and IGFBP-1 (each p < 0.05); (2) women with an episode of premature labor who delivered at term also had a higher mean concentration of PAPP-A (p < 0.05); and (3) acute histologic chorioamnionitis and spontaneous labor at term were not associated with significant changes in these analytes.

CONCLUSION

An episode of preterm labor involves the IGF system, supporting the view that the premature activation of parturition is a pathologic state, even in those women who delivered at term.

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.

A diagnostic profile on the PartoSure test

Introduction: Preterm birth (PTB) is common, occurring in over 10% of all live births globally, and is increasing worldwide. The limitations of traditional biomarkers of PTB, such as fetal fibronectin (fFN) and phosphorylated insulin-like growth factor-binding protein-1 (phIGFBP-1) have been well demonstrated in the literature. Therefore, augmenting clinical assessment with newer biomarkers, such as placental alpha macroglobulin-1 (PAMG-1); PartoSure, has the potential to improve disease monitoring and the best interventions. Areas covered: The present expert opinion evaluates the utility and limitations of PAMG-1; PartoSure as a biomarker for PTB in light of the current literature. Expert opinion: Although fFN, phIGFBP-1 and PAMG-1; PartoSure test had similar negative predictive value (NPV) and negative likelihood ratio (LR-), the PAMG-1; PartoSure test had the highest specificity, positive predictive value (PPV), and positive likelihood ratio (LR+) across all at-risk pregnant women. Although findings of this review may be encouraging, the PartoSure test should not be interpreted as absolute evidence for prediction of PTB. The PartoSure test result should always be used in conjunction with information available from the clinical evaluation of the pregnant woman and other diagnostic procedures such as cervical examination, assessment of uterine activity, and evaluation of other risk factors.

[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.

Effect of blood on ROM diagnosis accuracy of PAMG-1 and IGFBP-1 detecting rapid tests

Vaginal bleeding may be present in up to 30% of patients presenting with signs and symptoms of a rupture of the fetal membranes (ROM). The presence of blood may lead to false positive results with biochemical markers. The data presented in this study came from a multi-centric prospective observational clinical study that, for the first time, systematically evaluated the performance of placental alpha microglobulin-1 (PAMG-1) and insulin-like growth factor binding protein-1 (IGFBP-1) detecting tests in 151 women with vaginal bleedings as well as signs and symptoms indicative of ROM. Our data showed better performance for the PAMG-1 compared with the IGFBP-1 detecting tests in all quality parameters evaluated. In detail, sensitivity (SN) was 97.8% (91.0%), specificity (SP) was 91.5% (75.0%), positive predictive value (PPV) was 94.6% (83.5%) and negative predictive value (NPV) was 96.4% (85.7%) for PAMG-1 tests (and IGFBP-1 tests, respectively). A major difference between both tests was related to the number of non-evaluable test results (e.g., hidden bands due to blood smear on the test strips). While 2% of all results were not evaluable for PAMG-1 tests, this artifact appeared in 11% of the results obtained with IGFBP-1 tests. This difference and also those in Specificity and PPV were statistically significant, demonstrating superiority of PAMG-1 over IGFBP-1 detecting tests. In conclusion, the PAMG-1 detecting test was significantly less susceptible to interference by blood than the IGFBP-1 detecting test.

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.

Comparison of placental alpha microglobulin-1 in vaginal fluid with intra-amniotic injection of indigo carmine for the diagnosis of rupture of membranes

AIMS

The purpose of this study was to compare the diagnostic performance of an immunoassay for placental alpha microglobulin-1 (PAMG-1) in vaginal fluid with the intra-amniotic instillation of indigo carmine for the diagnosis of membrane rupture in patients with an equivocal status.

METHODS

A prospective multi-site study was performed involving women reporting signs, symptoms, or complaints suggestive of rupture of membrane (ROM) between 21 and 42 weeks of gestation without obvious leakage of fluid from the cervical os during sterile speculum examination and without confirmation of ROM by traditional methods.

RESULTS

A total of 140 patients were recruited with a prevalence of ROM of 19.3%. The PAMG-1 test had a sensitivity of 100.0% [confidence interval (CI) 0.87-1.0], specificity of 99.1% [(CI) 0.95-0.99], positive predictive value of 96.3% [(CI) 0.82-0.99], negative predictive value of 100.0% [(CI) 0.97-1.0], and ± likelihood ratios of 74.6 [(CI) 20.31-274.51] and 0.0 [(CI) 0.00-0.98].

CONCLUSIONS

The PAMG-1 immunoassay in vaginal fluid yielded results that were comparable to those of the instillation of indigo carmine into the amniotic cavity; therefore, we propose that PAMG-1 is a sensitive and specific test to assess ROM in patients with an equivocal diagnosis based on simple tests. This finding prompts consideration for the use of the noninvasive PAMG-1 test in situations where the use of the invasive dye test is not practical.

Serum β-human chorionic gonadotropin and interleukin-1 as diagnostic biomarkers for the premature rupture of membranes and chorioamnionitis

Chorioamnionitis is common in females with prematurely ruptured fetal membranes (PROM). The current diagnosis of PROM and preterm PROM (PPROM) is based on vaginal fluid analysis. The present study investigated the value of serum β-human chorionic gonadotropin (β-hCG) and interleukin-1 (IL-1) levels in diagnosing chorioamnionitis. In total, 150 term-pregnancy patients were included in the prospective study. A total of 50 females had normal pregnancies (control group) and 100 had PROM. One hour before delivery, 3 ml venous blood was collected and analyzed. Fetal membrane and placental tissue underwent histopathological analyses. Of the 100 term-pregnancy females, 56 had PROM and 44 had PROM combined with chorioamnionitis (PROM + C). The serum β-hCG levels for the control, PROM and PROM + C groups were 7,557.86±2,922.06, 636.96±14,379.10 and 50,310.34±22,874.82 IU/l, respectively. The receiver operating characteristic (ROC) for PROM and PROM + C groups (β-hCG ≥23,900.50 IU/l) had a sensitivity of 77.5% and a specificity of 78.6%. The level of IL-1 in the PROM + C group was higher compared to the control and PROM groups (0.58±0.05, 0.12±0.04 and 0.13±0.03 ng/ml, respectively). In conclusion, ROC for the PROM and PROM + C groups (IL-1 ≥0.38 ng/ml) had a sensitivity of 76.5% and a specificity of 72.6%. Therefore, serum β-hCG and IL-1 are potential biomarkers for diagnosing PROM and PROM + C, respectively.