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

Accuracy of the sonographic determination of estimated fetal weight in anhydramnios

OBJECTIVE

To determine whether the presence of anhydramnios significantly influences the sonographic estimated fetal weight (EFW) compared to a matched cohort with normal amniotic fluid volume.

METHODS

The study sample of this retrospective case-control study consisted of 114 pregnant women who presented to a Tertiary Perinatal Clinic between 2015 and 2020. 57 of them presented with an anhydramnios and a matched cohort of 57 women with normal amniotic fluid volume. At time of admission, gestational age varied between 22 + 4 and 42 + 6 weeks of pregnancy. All women underwent detailed ultrasound assessment for EFW and amniotic fluid index. To determine EFW Hadlock's estimation formula I was used which is based on measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL). The EFW was compared with the weight at delivery. The maximum time interval between measurement and delivery was 5 days.

RESULTS

There was neither a significant difference between the case and control group with regard to gestational age at ultrasound in days (median 249 days and 246 days, p = 0.97), nor to gestational age at birth (median 249 days and 247 days, p = 0.98). Concerning the newborns parameters, the body length at birth was not significantly different between the case and control group in centimeters (cm) (median 47 cm and 47 cm, p = 0.79). EFW in gram (g) was lower than birth weight in both groups and did not differ significantly between case and control group (estimated weight median 2247 g and 2421 g, p = 0.46; birth weight median 2440 g and 2475 g, p = 0.47). The difference between EFW and birth weight in percent (%) did not differ between the case and control group (median - 3.9% and - 5.6%, p = 0.70). The maternal parameters showed that the patients in the case group were younger (median 31 years and 38 years p = 0.20) and had a significantly higher body mass index (BMI) (median 27.3 kg/m2 vs 22.0 kg/m2, < 0.001) compared to the control group.

CONCLUSION

Our study shows for the first time that EFW in women with anhydramnios can be determined sonographically just as accurately as in a matched cohort with normal amniotic fluid volume. A reliable estimation of fetal weight is crucial for optimal assessment of the newborns prognosis and counseling of the parents especially when advising women in the early weeks of pregnancy at the limit of viability.

The Role of Pancreatic Stone Protein (PSP) as a Biomarker of Pregnancy-Related Diseases

Background: Pancreatic stone protein (PSP) is a biochemical serum marker that contains levels that are elevated in various inflammatory and infectious diseases. The role of PSP in the diagnosis of these diseases seems to be more important compared to clinically established biochemical serum markers in discriminating the severity of the same diseases. Standard values for PSP in pregnant women in relation to gestational age have been reported recently. Additionally, increased PSP levels have been observed to be associated with renal dysfunction in pregnant women. The aim of this study is to evaluate the diagnostic role of PSP in pregnancy-related diseases, such as pre-eclampsia (PE), hemolysis-elevated liver enzymes, and low platelet (HELLP) syndrome. In addition, the study aims to assess its diagnostic role in inflammation-triggered diseases as preterm premature rupture of membranes (PPROM) or COVID-19-positive pregnant women. Materials and Methods: In this single-centred prospective study performed at a tertiary university hospital between 2013 and 2021, we included 152 pregnant women who were diagnosed with either PE, HELLP syndrome, or PPROM. In December 2020, in the context of the COVID-19 pandemic, the Independent Ethics Committee (IEC) approved an amendment to the study protocol. Depending on the underlying disease, single or serial-serum PSP measurements were assessed. These PSP values were compared to PSP levels of women with normal pregnancies. Results: Pregnant women diagnosed with pre-eclampsia or HELLP syndrome had significantly increased PSP values (mean 9.8 ng/mL, SD 2.6) compared to healthy singleton pregnant women (mean 7.9 ng/mL, SD 2.6, p ≤ 0.001). There was no difference in serum PSP in pregnant women with PPROM compared to women with uncomplicated singleton pregnancies (mean in PPROM: 7.9 ng/mL; SD 2.9 versus mean in healthy pregnancies: 7.9 ng/mL; SD 2.6, p = 0.98). Furthermore, no difference in the PSP values in women with or without intra-amniotic infection was observed (infection: mean 7.9 ng/mL; SD 2.8 versus no infection: mean 7.8 ng/mL; SD 3, p = 0.85). The mean value of PSP in COVID-19-infected women during pregnancy (8.5 ng/mL, SD 2.3) was comparable to healthy singleton pregnancies (mean 7.9 ng/mL, SD 2.6), p = 0.24. Conclusions: The novel serum biomarker PSP is significantly upregulated in pregnant women with pre-eclampsia and HELLP syndrome. Our observations call for the further evaluation of PSP in randomized controlled clinical trials to demonstrate the actual role of PSP in pregnancy-related diseases and whether it may provide new approaches for the management and discrimination of the severity of these gestational conditions.

Comparison of placental α microglobulin-1 protein assay (Amnisure) with speculum examination for the diagnosis of premature preterm rupture of membranes (PPROM): a clinical evaluation

In this study, we aimed to compare the clinical outcomes of Premature Preterm Rupture of Membranes (PPROM) cases diagnosed by classical speculum examination and by placental alpha microglobulin-1 protein (PAMG-1) assay. The medical records of all patients with singleton pregnancies that were diagnosed with PPROM were retrospectively reviewed. Singleton pregnancies with PPROM diagnosis that was confirmed either by direct visualisation of amniotic fluid leaking through the cervix or by placental alpha microglobulin-1 protein (PAMG-1) assay if no amniotic fluid leakage was documented were included in the study. Demographics, prenatal and postnatal characteristics were reviewed from the medical charts and were recorded. The study included 138 pregnancies with PPROM; 111 patients in clinical speculum examination group and 27 in PAMG-1 assay group. There were no significant differences in maternal and pregnancy characteristics between the clinical speculum examination and PAMG-1 assay groups. Foetal outcomes were comparable between clinical speculum examination and PAMG-1 assay groups. In the clinical speculum examination group, there were nine (8.1%) chorioamnionitis cases, however, there were no chorioamnionitis cases in the PAMG-1 assay group during the latency period (p = .21).Impact statementWhat is already known on this subject? Placental alpha microglobulin-1 protein assay uses immunochromatography method to detect trace amount of placental alpha microglobulin-1 protein in vaginal fluids and has high sensitivity and specificity for ROM diagnosis. However, to the best of our knowledge, the clinical outcome of ROM cases detected by classical speculum examination and by placental alpha microglobulin-1 protein assay has not been compared in the literature previously.What do the results of this study add? Although statistically insignificant, cases diagnosed by PAMG-1 assay had lower risk of chorioamnionitis during latency period.What are the implications of these findings for clinical practice and/or further research? Whether cases diagnosed by PAMG-1 assay represent a milder form of rupture of membranes than cases diagnosed by classical speculum examination group warrants further research.

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.

Premature rupture of the membranes at 16 weeks: report of a successful outcome of pregnancy and review of the literature

Prelabor rupture of the fetal membranes (premature rupture of membranes, PROM) before or at the limit of fetal viability is condition associated with significant and serious pediatric morbidity and mortality. It is a rare problem, with an estimated incidence between 0.1 and 0.7%. Management of this condition is one of the most challenging clinical situations in obstetrics. We report the case of a pregnant woman presenting at 16 weeks gestation with ruptured membranes. The course of pregnancy was further complicated by complete placenta previa. Expectant management was undertaken, with term delivery and successful outcome of pregnancy. Expectant management is a reasonable approach in properly selected patients. Better understanding of the mechanisms of spontaneous membrane resealing is needed in order to improve poor outcomes. More published data and evidence are necessary to standardize treatment options for this rare condition.

First-trimester vaginal microbiome diversity: A potential indicator of preterm delivery risk

Preterm birth is a leading cause of global neonate mortality. Hospitalization costs associated with preterm deliveries present a huge economic burden. Existing physical/biochemical markers for predicting preterm birth risk are mostly suited for application at mid/late pregnancy stages, thereby leaving very short time (between diagnosis and delivery) for adopting appropriate intervention strategies. Recent studies indicating correlations between pre/full-term delivery and the composition of vaginal microbiota in pregnant women have opened new diagnostic possibilities. In this study, we performed a thorough meta-analysis of vaginal microbiome datasets to evaluate the utility of popular diversity and inequality measures for predicting, at an early stage, the risk of preterm delivery. Results indicate significant differences (in diversity measures) between ‘first-trimester’ vaginal microbiomes obtained from women with term and preterm outcomes, indicating the potential diagnostic utility of these measures. In this context, we introduce a novel diversity metric that has significantly better diagnostic ability as compared to established diversity measures. The metric enables ‘early’ and highly accurate prediction of preterm delivery outcomes, and can potentially be deployed in clinical settings for preterm birth risk-assessment. Our findings have potentially far reaching implications in the fight against neonatal deaths due to preterm birth.

Use of cervicovaginal PAMG-1 protein as a predictor of delivery within seven days in pregnancies at risk of premature birth

Background

To investigate the utility of vaginal placental alpha microglobulin-1 (PAMG-1) protein as a predictor of preterm delivery within 7 days in pregnancies at risk of premature birth.

Methods

This prospective study was performed in women at risk of premature birth. The levels of vaginal PAMG-1 and foetal fibronectin (fFN) and the transvaginal cervical length measurement (CLM) were investigated and compared.

Results

Seventy-two pregnant women were included in this study. The sensitivities of PAMG-1, fFN and CLM were 73.3, 73.6%, and 52.9%, respectively, while the specificities of PAMG-1, fFN and CLM were 92.9%, 94.3%, and 90.9%, respectively. The positive predictive values of PAMG-1, fFN and CLM were 73.3%, 82.3%, and 64.2%, respectively, and the negative predictive values of PAMG-1, fFN and CLM were 92.9%, 90.9%, and 86.2%, respectively.

Conclusion

The diagnostic accuracy of PAMG-1 is similar to that of fFN in terms of preterm labour detection within 7 days.

Factors affecting the rates of caesarean sections in cases with premature rupture of membranes (PROM) at term

The aim of this retrospective study was to investigate the factors affecting the rates of caesarean section in cases with premature rupture of membranes (PROM) in term pregnancies. Eighty-two term PROM patients who presented to Turgut Ozal University and Erzurum Nene Hatun Hospitals between 2012 and 2014 were included. The effects of demographics, nulliparity, active-latent phase durations, presence of meconium and chorioamnionitis, requirement of oxytocin and cervical dilation at the initial examination on C/S rates were assessed. The C/S rates were changed with the duration of active period and the duration of latent period. It was found that the presence of cervical dilation at the initial examination significantly reduced the risk for progress to C/S at a rate of 87.5%. C/S rates did not change with other variables. We conclude that the factors increasing the risk for C/S in PROM at term group are not different from the non-term PROM. Impact statement The aim of this retrospective study was to investigate the factors affecting the rates of caesarean section (C/S) in cases with premature rupture of membranes (PROM) in term pregnancies. The C/S rates were changed with the duration of active period and the duration of latent period. It was found that the presence of cervical dilation at the initial examination significantly reduced the risk for progress to C/S at a rate of 87.5%. We conclude that the factors increasing the risk for C/S in PROM at term group, are not different from the non-term PROM groups. Currently, the PROM is considered the start of a pathological process in both term and preterm pregnancies and also considered to increase the rates of caesarean sections. Studies on the management of PROM at term have concentrated rather on whether to intervene for accelerating the labour or spontaneous monitorisation. As found by the studies like this one in the literature, the factors having an impact on C/S rates in the cases of PROM at term are similar to those of non-PROM patients at term, may prevent clinicians from taking an invasive or aggressive approach towards the cases of PROM at term.

The role of placental alpha microglobulin-1 amnisure in determining the status of the fetal membranes; its association with preterm birth. Traditions … traditions …

The integrity of the fetal amnion-chorion is an imperative for the preservation of a normal pregnancy in the human. The diagnosis of the status of the fetal membranes has traditionally been reduced to either intact or ruptured. In the last decades, evidence has accumulated demonstrating that this clinical approach may well be an over simplification. Practically, all maternal organs experienced physiologic or eventually pathologic changes during the length of the gestational period. We propose that the fetal membranes are also significantly impacted by those changes. The accurate, specific, simplified and low-cost diagnosis of the status of the fetal membranes is of critical importance for the assessment of risk to the pregnancy followed by efficient and prompt treatment. The presence of placental alpha macroglobulin-1 in the vagina specifically indicates a disruption in the integrity of the fetal membranes and may indirectly mean increased risk for preterm birth. Further research to properly characterize this marker and its importance in the care of pregnant woman at risk for preterm birth is strongly recommended.

Comparative study of placental α-microglobulin-1, insulin-like growth factor binding protein-1 and nitrazine test to diagnose premature rupture of membranes: a randomized controlled trial

AIM

The aim of this study was to compare the accuracy of placental α-microglobulin-1 (PAMG-1), insulin-like growth factor binding protein-1 (IGFBP-1) and nitrazine test to diagnose premature rupture of membranes.

MATERIAL AND METHODS

A total of 120 pregnant women between 11 and 42 weeks with signs/symptoms of membrane rupture were eligible for our study. These women were evaluated with the PAMG-1, IGFBP-1, and nitrazine tests.

RESULTS

In the 120 women, the sensitivity, specificity, positive predictive value, and negative predictive value of PAMG-1, IGFBP-1 and nitrazine test were 100%, 100%, 100%, and 100%, 93.33%, 98.89%, 96.55% and 97.80%, and 93.33%, 94.44%, 84.85%, and 97.7%, respectively. In a comparison of the PAMG-1 test and the nitrazine test, positive coincidence rate was 84.85%, negative coincidence rate was 97.70%, total coincidence rate was 94.17%, and kappa value was 0.85. In a comparison of the PAMG-1 test and the IGFBP-1 test, the positive coincidence rate, negative coincidence rate and total coincidence rate were 96.55%, 97.80%, and 97.50%, and kappa value was 0.93.

CONCLUSION

PAMG-1 assay was the most accurate method to diagnose premature rupture of membranes with the highest sensitivity, specificity, positive predictive value and negative predictive value.

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.