Diagnosis of premature rupture of membranes: inspiration from the past and insights for the future

Pre-labor rupture of membranes and associated factors among pregnant women admitted to the maternity ward, Northwest Ethiopia

Pre-labor rupture of membranes (PROM) is the rupture of fetal membranes before the onset of labor. PROM is found in 3-15% of all pregnancies and 30-40% of preterm labor worldwide. The most serious complications are neonatal and prenatal mortality, which is higher in Africa, including Ethiopia. Despite a paucity of evidence on the magnitude and factors affecting PROM after 28 weeks of gestation but before the onset of labor (including both term and preterm PROM). Hence, the purpose of this study was to determine the magnitude and identify associated factors of the pre-labor rupture of membranes. An institutional-based cross-sectional study was conducted among 315 pregnant women from April 10, 2019 to June 30, 2019 at Debre Markos Referral Hospital. The samples were chosen using a systematic random sampling method among admitted pregnant women. The data were entered using EpiData entry version 4.2 and cleaned and analyzed using Stata/SE version 14.0. In binary logistic regressions, variables with a p-value <0.20 are selected for multivariable analysis. A multivariable logistic regression model with a 95% confidence interval and a p-value <0.05 was used to identify associated factors. In this study, the magnitude of PROM was 19%. Maternal monthly income ≤1000 birr [AOR: 3.33 (95%CI: 1.33, 8.33)], gestational age <37weeks [AOR: 3. 28 (95%CI: 1.53, 7.02)], multiple pregnancy [AOR: 4.14 (95%CI: 1.78, 9.62)], polyhydramnios [AOR: 5.06 (95%CI: 2.28, 11.23)] and history of abnormal vaginal discharge [AOR: 6.65 (95%CI: 2.62, 16.72)] were found significant associated factors. In conclusion, the magnitude of the pre-labor rapture of the membranes was higher than in previous studies. Hence, health professionals should strengthen counseling, early diagnosis, and treatment of infections, as well as focus on women with pregnancy-related risks, to reduce pre-labor rupture of membranes and improve fetal and perinatal health.

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.

Efficacy and Safety Analysis of Phloroglucinol in Combination with Oxytocin for the Induction of Labor in Women with Term Premature Rupture of Membranes (PROM)

Objective. The purpose of this study was to investigate the efficacy and safety of phloroglucinol in combination with oxytocin in the induction of labor in women who had experienced term premature rupture of membranes (PROM). Methods. Data from 100 women who experienced PROM between December 2020 and December 2021 were retrospectively evaluated in this study. The puerperae were categorized into observation and control groups based on their uterine contraction regimens. The observation group consisted of 53 participants that had been treated with phloroglucinol in combination with oxytocin, and the control group consisted of 47 participants that had been treated with oxytocin alone. It was observed and compared in terms of the Bishop score before and after the administration of the puerpera to see which group had the best index. A study was performed after the drug was administered to examine its effects on the duration of labor (including the first, second, and third stages of labor), the mode of delivery (including natural vaginal delivery and cesarean section), the incidence of adverse pregnancy outcomes (fetal distress and neonatal asphyxia), successful labor induction, and complication rates. Results. Patients in the observation group had a significantly higher Bishop score after administration than those in the control group ( $P<0.05$ ), although there was no difference between the two groups before administration. In comparison to the control group, the observation group had a significantly higher efficacy rate for drug administration ( $P<0.05$ ), as well as a significantly lower occurrence of the first stage of labor ( $P<0.05$ ), a higher rate of vaginal natural delivery and successful induction of labor ( $P<0.05$ ), and a significantly lower incidence of adverse pregnancy outcomes and complications ( $P<0.05$ ). Conclusion. In conclusion, the use of phloroglucinol in combination with intravenous oxytocin in the process of promoting cervical ripening and induction of labor for women with PROM who are at term was investigated. This study could help women speed up cervical dilation, improve the cervical Bishop scores, shorten the total labour process, improve the effective rate of vaginal delivery, and be very safe, making it a good candidate for clinical promotion and application.

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.

Effect of blood contamination on amniotic fluid detection in vitro using immunoassays

Objective: To determine the accuracy of Actim PROM^®, Amnisure^®, and ROM Plus^® tests for detecting amniotic fluid proteins in the setting of blood contamination.Methods: IGFBP-1 and AFP are proteins present in high concentrations in amniotic fluid, and are detected by three commercially-available immunoassays used for diagnosing ruptured membranes: Actim PROM^®, Amnisure^®, and ROM Plus^®. We used whole blood samples and diluted these with amniotic fluid (containing known concentrations of amniotic fluid proteins) to whole blood levels of 50, 20, 10, 5, and 1%. Actim PROM^®, Amnisure^®, and ROM Plus^® tests were performed on each sample in duplicate according to package insert instructions. Results were interpreted independently at 5, 10, 15, and 20 min by two obstetricians who were blinded to the concentrations of blood and amniotic fluid proteins in each sample. Results of each test were determined to be true positive, false negative, false positive, or true negative based on physician interpretation and whether amniotic fluid had been spiked into the samples in detectable concentrations. Overall accuracy, intraobserver concordance, and interobserver concordance, sensitivity, specificity, and predictive values for each test were calculated. Fisher exact test was used to compare test characteristics, with a p-value of <.05 considered significant.Results: Out of 120 tests performed, there were no false positive results for any test. Overall, ROM Plus^® had better accuracy (97.9%) than Amnisure^® (80.7%) or Actim^® PROM (78.3%). Intra- and interobserver concordance were similar for all three tests (98-100%). ROM Plus^® had significantly higher sensitivity than Amnisure^® and Actim^® PROM (p < .0001). There was no significant difference in sensitivity between Amnisure^® and Actim^® PROM (p = .51).Conclusion: ROM Plus^® maintains strong test characteristics for the detection of amniotic fluid proteins in the setting of blood contamination, and performs significantly better than Amnisure^® and Actim^® PROM tests in the presence of blood.

[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.

Placental protein 14 as a potential biomarker for diagnosis of preterm premature rupture of membranes

Premature rupture of membranes (PROM) is a common pregnancy complication that frequently results in maternal and perinatal morbidity. The present methods for diagnosing PROM do not satisfy clinical requirements. The present study aimed to examine the proteome profile of amniotic fluid (AF) and maternal plasma, screen unique proteins in AF, and evaluate their diagnostic value for diagnosing PROM. The proteome profiles of AF and maternal plasma were examined via liquid chromatography coupled with tandem mass spectrometry-based proteomic techniques. The protein expression levels of diagnostic candidates in AF, maternal plasma and vaginal fluid were determined by ELISA analysis and Magnetic Luminex^® screening assays. The diagnostic value of potential biomarkers was evaluated using receiver operating characteristic curves. A lateral flow assay was developed based on colloidal gold immunochromatography technology. The present study identified 540 unique proteins in AF, 12 of which were chosen for further detection. The present results demonstrated that expression levels of pulmonary surfactant-associated protein B, BPI fold-containing family A member 1, zymogen granule protein 16 homolog B, EGF-containing fibulin-like extracellular matrix protein 1, keratin, type II cytoskeletal 4, keratin, type I cytoskeletal 19, placental protein 14 (PP14), insulin-like growth factor-binding protein 2, mesothelin and serpin family B member 3 were significantly higher in AF compared with in maternal plasma (P<0.01). Furthermore, PP14 was observed to have excellent diagnostic accuracy for preterm PROM (PPROM), with a respective sensitivity and specificity of 100 and 87.5% when the cutoff value was 0.008 µg/ml. The PP14-based lateral flow assay demonstrated a visual detection threshold of 0.008 µg/ml. The results from the present study suggested that PP14 may be a novel potential biomarker for PPROM, and may be developed into a lateral flow assay for bedside application to rapidly diagnose PPROM.

PROM and Labour Effects on Urinary Metabolome: A Pilot Study

Since pathologies and complications occurring during pregnancy and/or during labour may cause adverse outcomes for both newborns and mothers, there is a growing interest in metabolomic applications on pregnancy investigation. In fact, metabolomics has proved to be an efficient strategy for the description of several perinatal conditions. In particular, this study focuses on premature rupture of membranes (PROM) in pregnancy at term. For this project, urine samples were collected at three different clinical conditions: out of labour before PROM occurrence (Ph1), out of labour with PROM (Ph2), and during labour with PROM (Ph3). GC-MS analysis, followed by univariate and multivariate statistical analysis, was able to discriminate among the different classes, highlighting the metabolites most involved in the discrimination.

Point-of-care diagnostics to improve maternal and neonatal health in low-resource settings

Each day, approximately 830 women and 7400 newborns die from complications during pregnancy and childbirth. Improving maternal and neonatal health will require bringing rapid diagnosis and treatment to the point of care in low-resource settings. However, to date there are few diagnostic tools available that can be used at the point of care to detect the leading causes of maternal and neonatal mortality in low-resource settings. Here we review both commercially available diagnostics and technologies that are currently in development to detect the leading causes of maternal and neonatal mortality, highlighting key gaps in development where innovative design could increase access to technology and enable rapid diagnosis at the bedside.

Qualitative Determination of Human Chorionic Gonadotropin in Vaginal Washings for the Early Diagnosis of Premature Rupture of Fetal Membranes

Purpose This study aimed to evaluate and validate the qualitative human chorionic gonadotropin β subunit (β-hCG) test of the vaginal fluid washings of pregnant women with premature rupture of fetal membranes (PROM). Methods Cross-sectional study of pregnant women between gestational weeks 24 and 39 who underwent consultations in one of our institutions. They were divided into two groups: group A (pregnant women clinically diagnosed with PROM) and group B (pregnant women without loss of amniotic liquid). The patients were subjected to a vaginal fluid washing with 3 mL of saline solution, which was aspirated subsequently with the same syringe. The solution was immediately sent to the laboratory to perform the vaginal β-hCG test with cut-off points of 10 mIU/mL (β-hCG-10) and/or 25 mIU/mL (β-hCG-25). Results The β-hCG-10 test of the vaginal secretion was performed in 128 cases. The chi-squared test with Yates' correction showed a statistically significant difference between the 2 groups (p = 0.0225). The sensibility, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy parameters were 77.1%, 43.6%, 52.3%; 70.4%; and 58.6% respectively. The β-hCG-25 test of the vaginal washing was performed in 49 cases. The analysis by Fisher's exact test showed a statistically significant difference between the groups (p = 0.0175). The sensibility, specificity, PPV, NPV, and accuracy parameters were 44.4%, 87.1%, 66.6%; 72.9%; and 71.4% respectively. Conclusions The β-hCG-25 test showed better accuracy for the diagnosis of PROM, and can corroborate the early diagnosis of PROM because it is a simple and quick exam.

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 rapid immunoassays for rupture of fetal membranes

Background

Rupture of membranes (ROM) before the onset of uterine contractions, particularly in pregnancies less than 37 weeks gestational age, is a common diagnostic problem in obstetrical practice. Timely detection of ROM is vital to support gestational age-specific interventions to optimize perinatal outcomes and minimize the risk of serious complications such as preterm delivery, fetal distress and maternal/fetal infections. Rapid bedside immunoassay tests designed to detect amniotic fluid proteins in cervicovaginal fluids have emerged as valuable clinical tools to provide timely ROM diagnosis.

Methods

In this prospective observational study, two commercially-available immunoassay tests (ROM Plus®, AmniSure®) were evaluated concurrently in 111 pregnant women who presented with the chief complaint of ROM. Immunoassay results were compared to clinical parameters for determining ROM via comprehensive, retrospective clinical chart review. Diagnostic performance characteristics were calculated including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy.

Results

Overall, diagnostic performance characteristics were robust and similar between ROM Plus® and AmniSure®, respectively: sensitivity (96.4 and 89.3%), specificity (98.8 and 100%), PPV (96.4 and 100%), NPV (98.8% and 96.5) and accuracy (98.2 and 97.3%). For term patients (≥37 weeks gestation), the sensitivities were 93.8 and 81.3% and specificities were 97.1 and 100% for ROM Plus® and AmniSure®, respectively. For preterm patients (<37 weeks gestation), both immunoassay tests provided exact concordance with clinical confirmation of ROM resulting in 100% diagnostic accuracy.

Conclusions

Both rapid immunoassay tests provided similarly excellent diagnostic accuracy for the rapid detection of ROM with only two discrepant results for ROM Plus® and three discrepant results for AmniSure® compared to clinical confirmation. The findings from this study recommend these tests for pregnant women presenting with suspected ROM to guide correct clinical management decisions to improve obstetrical and neonatal outcomes.

Trial registration

ClinicalTrials.gov, NCT02208011 (1 August 2014).

A Sanitary Pad for Self-Assessment of Rupture of Membranes

BACKGROUND

Multistep immunoassay kits for the diagnosis of rupture of membranes are relatively complex and are not designed to be used by pregnant women themselves. These kits require procedural steps of specimen extraction and preparation. We evaluated the ability of a sanitary pad containing a qualitative immunoassay for alpha-fetoprotein (AFP) to serve as a one-step self-test to detect amniotic fluid leakage.

TECHNIQUE

Four sets of pads were evaluated. The pads in the study set were worn by 288 pregnant women with confirmed rupture of membranes. Three controls were evaluated: 1) pads worn by 93 pregnant women with intact membranes, 2) additional pads instilled with urine specimens obtained from the 381 women described previously (study set plus control set 1), and 3) pads instilled with semen collected from 40 men.

EXPERIENCE

All 288 pads that absorbed amniotic fluid had positive results. Approximately half of the pads absorbed with normal vaginal discharge had a sufficient amount to yield valid results, which were all negative. All 381 pads with instilled urine and all 40 pads with instilled semen had negative results.

CONCLUSION

An immunoassay for AFP, embedded in a pad, appears to be a feasible and reproducible self-test for the detection of rupture of membranes.

Maternal and fetal outcomes in term premature rupture of membrane

BACKGROUND

Premature rupture of membrane (PROM) is linked to significant maternal prenatal mortalities and morbidity. In Ethiopia, where maternal mortality is still high, the maternal and fetal outcomes in PROM is very important to decrease maternal and child mortality and for better management and prevention of complications. Thus, this study aimed to detect the maternal and fetal outcomes and associated factors in term PROM at Mizan-Aman General Hospital, south-west Ethiopia.

METHODS

A retrospective cross sectional study was conducted using data available at Mizan-Aman General Hospital during a period of 3 years (January 2011 to December 2013). We examined records of 4 525 women who gave birth in the hospital; out of these women, 185 were diagnosed with term PROM and all of them were included in the study. The data of these women were collected using a checklist based on registration books. The data were analyzed using SPSS version 20.0 statistical package. The association between independent and dependent variables was assessed by bivariate and multiple logistic regression analyses. 95%CI and P value less than 0.05 were considered statistically significant.

RESULTS

Of the 4 525 women who gave birth in the hospital, 202 were complicated by term PROM. About 22.2% of the women showed unfavorable maternal outcomes. The most common cause of maternal morbidity and mortality was puerperal sepsis. About 33.5% of neonates experienced unfavorable outcomes. The duration of PROM >12 hours (AOR=5.6, 95%CI 1.3-24.1) latency >24 hours (AOR=2.8, 95%CI 1.7-11.8), residing in rural areas (AOR=4.2, 95%CI 3.96-29.4) and birth weight less than 2 500 g were associated with unfavorable outcomes.

CONCLUSION

Women residing in rural areas, long latency, and neonates with birth weight less 2 500 g may have unfavorable outcomes. Therefore, optimum obstetric and medical care is essential for the reduction of the devastating complications related to disorders.

ROM Plus(®): accurate point-of-care detection of ruptured fetal membranes

Accurate and timely diagnosis of rupture of fetal membranes is imperative to inform and guide gestational age-specific interventions to optimize perinatal outcomes and reduce the risk of serious complications, including preterm delivery and infections. The ROM Plus is a rapid, point-of-care, qualitative immunochromatographic diagnostic test that uses a unique monoclonal/polyclonal antibody approach to detect two different proteins found in amniotic fluid at high concentrations: alpha-fetoprotein and insulin-like growth factor binding protein-1. Clinical study results have uniformly demonstrated high diagnostic accuracy and performance characteristics with this point-of-care test that exceeds conventional clinical testing with external laboratory evaluation. The description, indications for use, procedural steps, and laboratory and clinical characterization of this assay are presented in this article.

Accurate Point-of-Care Detection of Ruptured Fetal Membranes: Improved Diagnostic Performance Characteristics with a Monoclonal/Polyclonal Immunoassay

OBJECTIVE

Accurate and timely diagnosis of rupture of membranes (ROM) is imperative to allow for gestational age-specific interventions. This study compared the diagnostic performance characteristics between two methods used for the detection of ROM as measured in the same patient.

METHODS

Vaginal secretions were evaluated using the conventional fern test as well as a point-of-care monoclonal/polyclonal immunoassay test (ROM Plus^®) in 75 pregnant patients who presented to labor and delivery with complaints of leaking amniotic fluid. Both tests were compared to analytical confirmation of ROM using three external laboratory tests. Diagnostic performance characteristics were calculated including sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy.

RESULTS

Diagnostic performance characteristics uniformly favored ROM detection using the immunoassay test compared to the fern test: sensitivity (100% vs. 77.8%), specificity (94.8% vs. 79.3%), PPV (75% vs. 36.8%), NPV (100% vs. 95.8%), and accuracy (95.5% vs. 79.1%).

CONCLUSIONS

The point-of-care immunoassay test provides improved diagnostic accuracy for the detection of ROM compared to fern testing. It has the potential of improving patient management decisions, thereby minimizing serious complications and perinatal morbidity.

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.

Fetal fibronectin (Quick Check fFN test) versus placental alpha microglobulin-1 (AmniSure test) for detection of premature rupture of fetal membranes

OBJECTIVES

To compare accuracy of fetal fibronectin (fFN) versus placental alpha microglobulin-1 for detection of premature rupture of fetal membranes (PROM).

METHODS

Two hundred and twenty pregnant women >34 and <37 weeks were included in this comparative prospective study and divided into two groups according to presence or absence of PROM. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive ferning, positive nitrazine test, confirmed by visualization of fluid passing from the cervical canal and amniotic fluid index ≤5 cm measured by trans-abdominal ultrasound. Patients included in this study were examined by sterile speculum for visualization of membranes and for collection of samples (swabs) from posterior vaginal fornix.

RESULTS

Sensitivity and specificity of AmniSure test to diagnose PROM were 97.3 and 98.2 %, respectively, compared with 94.5 and 89.1 %, respectively, for fFN test. Positive predictive value, negative predictive value, and accuracy of AmniSure test to diagnose PROM were 98.2, 97.3, and 97.7 %, respectively, compared with 89.7, 94.2, and 91.8 %, respectively, for fFN test. Predictive values and accuracy of fFN test to diagnose PROM were statistically insignificant compared with predictive values and accuracy of ferning, nitrazine and AmniSure tests.

CONCLUSION

fFN bedside test is better than nitrazine and ferning tests in detection of PROM, but is not suited for identification of clinically difficult cases with suspected PROM, because, it is influenceable and can give false-positive results in preterm labor, women >34 gestational weeks and after any vaginal manipulation without PROM.

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.

Insulin-like growth factor binding protein-1 (Actim PROM test) for detection of premature rupture of fetal membranes

AIM

This study was designed to detect the accuracy of the insulin-like growth factor binding protein-1 (IGFBP-1) in diagnosing premature rupture of fetal membranes.

MATERIALS AND METHODS

A total of 150 pregnant women after 37 weeks' gestation were included in this study and divided into two groups according to presence or absence of premature rupture of the membranes (PROM); 75 patients with PROM were included in group I and 75 patients without PROM were included in group II as controls. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive Ferning pattern, positive Nitrazine test, confirmed by visualization of fluid passing from the cervical canal during sterile speculum examination and transabdominal ultrasound to measure the amniotic fluid index.

RESULTS

In this study, the sensitivity and the specificity of IGFBP-1 (Actim PROM test) in diagnosing PROM were 89.3% and 82.7%, respectively, as compared with 84% sensitivity and 78.7% specificity for Ferning test, and 86.7% sensitivity and 81.3% specificity for Nitrazine test. The positive predictive value (PPV) and negative predictive value (NPV) of IGFBP-1 were 83.8% and 88.6%, respectively, as compared with 79.7% PPV and 83.1% NPV for the Ferning test, and 82.2% PPV and 85.9% NPV for the Nitrazine test. The IGFBP-1 was more accurate (86%) for detection of PROM than the Ferning (81.3%) or Nitrazine (84.0%) tests.

CONCLUSION

The Actim PROM test for detection of IGFBP-1 in the vaginal fluid is a simple bedside test and can be used as a complimentary test to confirm the clinical diagnosis of PROM.

Fetal fibronectin (Quick Check fFN test(®)) for detection of premature rupture of fetal membranes

OBJECTIVES

This study was designed to detect the accuracy of the fetal fibronectin (Quick Check fFN test(®)) in diagnosing premature rupture of fetal membranes.

STUDY DESIGN

This comparative prospective study was carried out over 1 year in Ahmadi Kuwait Oil Company (KOC) Hospital, Kuwait from March 2011 till March 2012.

PATIENTS AND METHODS

Two hundred and twenty (220) pregnant women >34 and <37 weeks gestation were included in this study and divided into two groups according to presence or absence of PROM; 110 patients with PROM were included in group I, and 110 patients without PROM were included in group II as controls. Patients with multiple pregnancies or >37 weeks gestation or not sure of dates or fetal distress or vaginal bleeding or preterm labor or chorioamnionitis were excluded from this study. The diagnosis of PROM was based on patient's history of sudden gush of water, pooling of amniotic fluid, positive ferning pattern, positive nitrazine test, confirmed by visualization of fluid passing from the cervical canal during sterile speculum examination and Trans-abdominal ultrasound to measure the amniotic fluid index (AFI ≤ 5 cm in PROM). The gestational age was calculate from the first day of LMP and confirmed by early ultrasound scan (done before 20 weeks gestation). Patients included in this study were subjected to standard examination, trans-abdominal ultrasound and sterile speculum examination to detect amniotic fluid pooling through the cervical canal and for collection of samples on admission. Some laboratory investigations were done to exclude chorioamnionitis (maternal fever, maternal tachycardia, fetal tachycardia, maternal leucocytosis, CRP).

RESULTS

In this study, the sensitivity and the specificity of fetal fibronectin in diagnosing PROM were 94.5 and 89.1 %, respectively, as compared with 84.5 % sensitivity and 78.2 % specificity for Ferning test, respectively, and 87.3 % sensitivity and 80.9 % specificity for Nitrazine test, respectively. The PPV and NPV of fetal fibronectin were 89.7 and 94.2 %, respectively, as compared with 79.5 % PPV and 83.5 % NPV for Ferning test, respectively, and 82.1 % PPV and 86.4 % NPV for Nitrazine test, respectively. Fetal fibronectin was more accurate (91.8 %) for detection of PROM than Ferning (81.4 %) or Nitrazine (84.1 %) tests.

CONCLUSION

The Quick Check fFN test(®) for detection of the fetal fibronectin in the vaginal fluid is a simple bedside test, more sensitive, and specific than Ferning and Nitrazine tests, it can be used as complimentary test to confirm the clinical diagnosis of premature rupture of fetal membranes.

The clinical significance of a positive Amnisure test in women with preterm labor and intact membranes

OBJECTIVE

This study was conducted to examine the frequency and clinical significance of a positive Amnisure test in patients with preterm labor and intact membranes by sterile speculum exam.

STUDY DESIGN

A retrospective cohort study was performed including 90 patients with preterm labor and intact membranes who underwent Amnisure tests prior to amniocentesis (< 72 h); most patients (n=64) also underwent fetal fibronectin (fFN) tests. Amniotic fluid (AF) was cultured for aerobic/anaerobic bacteria and genital mycoplasmas and assayed for matrix metalloproteinase-8.

RESULTS

(1) the prevalence of a positive Amnisure test was 19% (17/90); (2) patients with a positive Amnisure test had significantly higher rates of adverse pregnancy and neonatal outcomes (e.g., impending preterm delivery, intra-amniotic infection/inflammation, and neonatal morbidity) than those with a negative Amnisure test; (3) a positive test was associated with significantly increased risk of intra-amniotic infection and/or inflammation, delivery within 7, 14, or 28 days and spontaneous preterm birth (< 35 weeks) among patients with a negative fFN test.

CONCLUSIONS

A positive Amnisure test in patients with preterm labor and intact membranes is a risk factor for adverse pregnancy outcome, particularly in patients with a negative fFN test. A positive Amnisure test in patients without symptoms or signs of ROM should not be taken as an indicator that membranes have ruptured.

Practicability of vaginal washing fluid creatinine level in detecting premature rupture of membranes

OBJECTIVE

The purpose of this study was to evaluate the reliability of vaginal washing fluid creatinine level for the diagnosis of premature rupture of membranes (PROM).

METHOD

A prospective diagnostic study performed in Shahid Sedoughi Hospital on 160 pregnant women (30 definite PROM, 30 no PROM and 100 suspected PROM) at 28-40 weeks of gestation. The vagina was washed by injection with a syringe filled with 3 ml of saline solution, and the washing fluid was collected from the posterior vaginal fornix and send to laboratory. Creatinine values in vaginal washing were measured and compared.

RESULT

The mean vaginal fluid creatinine levels in definite PROM group, suspected PROM and no PROM were 0.40 ± 0.20, 0.16 ± 0.04 and 0.08 ± 0.01 mg/dl, respectively, where the difference was statistically significant (P = 0.001). The sensitivity, specificity, positive and negative predictivity values and accuracy were 98.7, 100, 100, 98.8 and 87.1%, respectively, in detecting PROM by evaluation of vaginal fluid creatinine concentration with cut-off value of 0.14 mg/dl.

CONCLUSION

This study showed that creatinine determination in vaginal washing fluid is a useful marker for PROM diagnosis. It is a reliable, simple, cheap and rapid test.

Placental alpha microglobulin-1 (AmniSure(®) test) for detection of premature rupture of fetal membranes

OBJECTIVES

This study was designed to detect the accuracy of the placental alpha microglobulin-1 (PAMG-1) (AmniSure(®) test) to diagnose premature rupture of the fetal membranes (PROM).

STUDY DESIGN

This comparative prospective study was carried out over 2 years in Al-Rashid Maternity Hospital, Kuwait from January 2006 till January 2008.

PATIENTS AND METHODS

One hundred and fifty (150) pregnant women after 37 weeks gestation were included in this study for induction of labor and divided into two groups according to the presence or absence of PROM; 75 patients with PROM were included in group I and 75 patients without PROM were included in group II as controls. Patients with multiple pregnancies or fetal distress or vaginal bleeding or preterm labor or chorioamnionitis were excluded from this study. Trans-abdominal ultrasound was done to detect the gestational age and the amniotic fluid index (AFI ≤5 cm in PROM) followed by sterile speculum examination to detect amniotic fluid pooling from the cervical canal and for the collection of samples.

RESULTS

In this study, the sensitivity and the specificity of PAMG-1 to diagnose PROM were 97.33 and 98.67%, respectively, compared with 84% sensitivity and 78.67% specificity for Ferning test and 86.67% sensitivity and 81.33% specificity for Nitrazine test. The positive predictive value (PPV) and negative predictive value (NPV) of PAMG-1 were 98.64 and 97.37%, respectively, compared with 79.74% PPV and 83.1% NPV for Ferning test and 82.28% PPV and 85.91% NPV for Nitrazine test. PAMG-1 was accurate (98%) for detection of PROM than Ferning (81.33%) or Nitrazine (84.0%) tests.

CONCLUSION

Detection of the PAMG-1 in the vaginal fluid using AmniSure(®) test is an accurate method to diagnose rupture of the fetal membranes, with high sensitivity, specificity, negative and positive predictive values.