Comparison of rapid immunoassays for rupture of fetal membranes

[Pelvic exam in gynecology and obstetrics: Guidelines for clinical practice]

OBJECTIVE

To provide guidelines for the pelvic clinical exam in gynecology and obstetrics.

MATERIAL AND METHODS

A multidisciplinary experts consensus committee of 45 experts was formed, including representatives of patients' associations and users of the health system. The entire guidelines process was conducted independently of any funding. The authors were advised to follow the rules of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasized.

METHODS

The committee studied 40 questions within 4 fields for symptomatic or asymptomatic women (emergency conditions, gynecological consultation, gynecological diseases, obstetrics, and pregnancy). Each question was formulated in a PICO (Patients, Intervention, Comparison, Outcome) format and the evidence profiles were produced. The literature review and recommendations were made according to the GRADE® methodology.

RESULTS

The experts' synthesis work and the application of the GRADE method resulted in 27 recommendations. Among the formalized recommendations, 17 present a strong agreement, 7 a weak agreement and 3 an expert consensus agreement. Thirteen questions resulted in an absence of recommendation due to lack of evidence in the literature.

CONCLUSIONS

The need to perform clinical examination in gynecological and obstetrics patients was specified in 27 pre-defined situations based on scientific evidence. More research is required to investigate the benefit in other cases.

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.

Prelabor Rupture of Membranes: ACOG Practice Bulletin, Number 217

Preterm birth occurs in approximately 10% of all births in the United States and is a major contributor to perinatal morbidity and mortality (). Prelabor rupture of membranes (PROM) that occurs preterm complicates approximately 2-3% of all pregnancies in the United States, representing a significant proportion of preterm births, whereas term PROM occurs in approximately 8% of pregnancies (). The optimal approach to assessment and treatment of women with term and preterm PROM remains challenging. Management decisions depend on gestational age and evaluation of the relative risks of delivery versus the risks (eg, infection, abruptio placentae, and umbilical cord accident) of expectant management when pregnancy is allowed to progress to a later gestational age. The purpose of this document is to review the current understanding of this condition and to provide management guidelines that have been validated by appropriately conducted outcome-based research when available. Additional guidelines on the basis of consensus and expert opinion also are presented. This Practice Bulletin is updated to include information about diagnosis of PROM, expectant management of PROM at term, and timing of delivery for patients with preterm PROM between 34 0/7 weeks of gestation and 36 6/7 weeks of gestation.

Diagnosis of rupture of membranes: AmniSure, clinical assessment, and the Food and Drug Administration warning

BACKGROUND

An accurate diagnosis of rupture of membranes is critical to the rendering of appropriate maternity care in both preterm and term patients. Immunoassays, such as the one detecting placental alpha microglobulin-1 (AmniSure) in cervicovaginal secretions, have replaced the traditional speculum-based assessment in some clinical settings; however, the Food and Drug Administration recently issued a warning regarding the potential risks of using the test in isolation.

OBJECTIVE

The study aimed to report the performance of AmniSure as a first-line nurse-administered screening test for rupture of membranes in our teaching county hospital obstetrical triage unit and as part of a clinical protocol to diagnose rupture of membranes.

STUDY DESIGN

We conducted a retrospective secondary analysis of 310 randomly selected term and preterm patients with concern for rupture of membranes screened with the AmniSure test. We systematically reviewed medical records to determine membrane status at the time of the AmniSure test. We calculated test characteristics of the AmniSure test used independently and in conjunction with speculum-based assessment.

RESULTS

Of 302 women evaluated for retrospective determination of membrane status at 17 to 41 weeks' gestation (median, 36.6 weeks' gestation), 208 (68.9%) were intact and 94 (31.1%) were ruptured at the time of the AmniSure test using a gold standard of retrospective membrane status determined by medical record review. A total of 4 false-negative AmniSure results and 16 false-positive AmniSure results were identified. The AmniSure test used independently had a sensitivity of 95.7%, specificity of 92.3%, positive predictive value of 84.9%, and negative predictive value of 98.0%. A rupture of membranes protocol combining AmniSure and clinical assessment had a sensitivity of 98.2%, specificity of 99.5%, positive predictive value of 100.0%, and negative predictive value of 100.0%.

CONCLUSION

The AmniSure has a high sensitivity as a first-line nurse-administered screening test for membrane rupture. Consistent with the Food and Drug Administration warning, the sensitivity, specificity, positive predictive value, and negative predictive value are improved when it is used as part of a clinical protocol and not in isolation. Determination of membrane status remains challenging in a small subset of patients, especially those with an equivocal speculum-based assessment; therefore, engaging women in their care and careful follow-up for identifying persistent or recurrent symptoms are required.

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.

The Prevalence and Payer Costs of Potentially Avoidable Emergent Care Visits for Suspected Amniotic Membrane Rupture in Pregnant Women

BACKGROUND

Concern over amniotic fluid leakage is common among pregnant women. Uncertainty about prelabor rupture of amniotic membranes (PROM) can lead women to present to emergency departments or to labor and delivery units for medical evaluation. Many of such visits do not result in delivery, yet they carry significant, and potentially unnecessary, healthcare expenditures.

OBJECTIVE

To estimate the prevalence and payer cost of potentially avoidable visits by pregnant women to an emergent care facility (including emergency departments, labor and delivery units, or observation units) for suspected PROM.

METHODS

This study included 2 processes-an electronic medical records chart review and a commercial health insurance claims data analysis. The medical chart review included 843 scheduled and 1250 unscheduled pregnancy-related visits at Robert Wood Johnson University Hospital between January 4 and June 30, 2017, which was conducted to determine the rates of visits by pregnant women with suspected PROM and their results (ie, hospital admission or discharge). In addition, we performed a retrospective analysis of medical claims data from the Truven Health MarketScan Commercial Database to measure population-level incidence rates and the costs of pregnancy-related emergent care visits for suspected PROM.

RESULTS

Of the 1250 unscheduled visits reviewed, 663 did not result in delivery; of these, 68 had a primary complaint of suspected PROM, and 55 (81%) of them were discharged with PROM ruled out. Of all scheduled and unscheduled nondelivery visits (N = 1069), 5.1% (N = 55) were associated with suspected PROM but were discharged home with PROM ruled out. In the commercial claims analysis, the average rate of emergent care visits by pregnant women was 436.69 per 1000 deliveries, with an estimated average cost of $1428 per visit (in 2018 dollars), or $0.58 per member per month. Applying the rates from our chart review to the claims data, we estimated that commercial insurers pay, on average, for approximately 22.47 facility visits per 1000 deliveries for suspected and ruled-out PROM.

CONCLUSIONS

Our findings suggest that for most PROM cases that do not result in delivery, PROM is ruled out and patients are sent home. Reducing the number of PROM-related visits to emergent care facilities that result in ruled-out PROM could reduce healthcare costs and help patients and providers avoid these inconvenient visits.

Cytokines in Preterm Delivery: Proposal of a New Diagnostic Algorithm

Predicting preterm delivery within 7 days is very important for the proper timing of glucocorticosteroid administration. If within 7 days after glucocorticosteroid administration, the delivery does not occur, it remains questionable if repeated glucocorticosteroid therapy results in improved infant respiratory function. Therefore, differentiation of preterm delivery from false preterm delivery is clinically significant. The aim of this study was to create a diagnostic algorithm to distinguish preterm delivery from false preterm delivery on the basis of concentrations of selected cytokines. The study group (n = 622) were patients hospitalized due to threatened preterm delivery. To assess the concentration of cytokines in the serum, we used a multiplex method, which allows simultaneous determination of 13 cytokines. The sets consist of the following cytokines: IGFBP-1, IGFBP-2, BDNF, L-Selectin, E-Selectin, ICAM-1, PECAM, VCAM-1, MIP-1d, MIP-3b, Eotaxin-1, Eotaxin-2, and BLC. In the study group, 67.8% patients had preterm delivery and 32.2% had false preterm delivery. Based on the analysis of cytokine concentrations, a classification tree to distinguish between preterm delivery and false preterm delivery was created. Our findings show the possibility of prediction of preterm delivery with the use of a classification and regression tree of selected cytokine concentration.