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AmniSure Placental Alpha-Microglobulin-1 Rapid Immunoassay versus Standard Diagnostic Methods for Detection of Rupture of Membranes

Abstract

The purpose of this study was to compare the AmniSure rapid immunoassay with standard methods for diagnosing rupture of fetal membranes. Patients presenting with signs/symptoms of membrane rupture between 15 and 42 weeks of gestation were invited to participate. Standard/control methods were performed to establish a diagnosis and compare it with AmniSure results. AmniSure performance metrics and their 95% confidence intervals were calculated. A total of 203 patients agreed to participate. Discrepancies between the control method and AmniSure were noted in seven cases. In these cases, true positives and negatives were determined by retesting with the control method and AmniSure and by noting sonographic evidence of low amniotic fluid. In the final analysis, the AmniSure diagnostic test demonstrated a sensitivity of 98.9%, specificity of 100%, positive predictive value of 100%, and a negative predictive value of 99.1%. AmniSure is highly accurate in diagnosing fetal membrane rupture.

Keywords
AmniSure ROM test, rupture of membranes, PAMG-1 immunoassay

Measurement of Placental Alpha-Microglobulin-1 in Cervicovaginal Discharge to Diagnose Rupture of Membranes

Abstract

Objective: To compare the accuracy of an immunoassay to measure levels of placental alpha-microglobulin-1 in cervicovaginal secretions with that of conventional clinical assessment for the diagnosis of rupture of membranes.

Methods: A prospective observational study was performed in consecutive patients with signs or symptoms of rupture of membranes at Seoul National University Hospital from March 2005 to February 2006. Initial evaluation included both the standard clinical evaluation for rupture of membranes and placental alpha-microglobulin-1 immunoassay. Rupture of membranes was diagnosed if fluid was seen leaking from the cervical os or if two of the following three conditions were present: pooling of fluid, positive nitrazine test, or ferning. Rupture of membranes was diagnosed definitively on review of the medical records after delivery.

Results: Of 184 patients (11– 42 weeks of gestation), rupture of membranes was diagnosed at initial presentation in 76% (139 of 184) using conventional clinical assessment and 88% (161 of 184) using placental alpha-microglobulin-1 immunoassay. Follow-up confirmed that a total of 159 of 183 patients (87%) had rupture of membranes at their initial presentations. Using this longitudinal assessment as the clinical gold standard, placental alpha-microglobulin-1 immunoassay confirmed rupture of membranes at initial presentation with a sensitivity of 98.7% (157 of 159), specificity of 87.5% (21 of 24), positive predictive value of 98.1% (157 of 160), and negative predictive value of 91.3% (21 of 23). Placental alpha-microglobulin-1 immunoassay was better than both the conventional clinical assessment and the nitrazine test alone in confirming the diagnosis of rupture of membranes.

Conclusion: Measurement of placental alpha-microglobulin-1 in cervicovaginal secretions is superior to conventional clinical assessment in the diagnosis of rupture of membranes.

Keywords
AmniSure ROM test, rupture of membranes, PAMG-1 immunoassay

Is AmniSure useful in the management of women with prelabour rupture of the membranes?

Abstract

Aims: Prelabour rupture of membranes (PROM), whether at term or preterm, can be a difficult diagnosis to confirm. Clinician uncertainty often leads to unnecessary intervention for risk management reasons. AmniSure is a bedside immunoassay for placental alpha macroglobulin-1 (PAMG-1), which has been shown to have high sensitivity and specificity in the diagnosis of PROM. However, whether the use of Manicured alters clinical management remains Untested. The objective of this study was to assess the clinical utility of AmniSure.

Methods: A prospective cohort study of 184 women presenting with a history of PROM to a tertiary maternity hospital. Before and after AmniSure, the attending clinician assessed and recorded membrane status (PROM or intact), his⁄her level of confidence in this diagnosis, and the intended management plan.

Results: There was clinician uncertainty regarding the diagnosis of PROM in 83 (47%) women. AmniSure significantly increased clinician confidence and led to a change of intended management in 23 (13%) women. In 33 women presenting with possible preterm PROM, seven thought to have PROM before AmniSure had a negative test, leading to a change of management in these women.

Conclusions: AmniSure is clinically useful when the clinician is uncertain about the diagnosis but not useful when the clinician is confident about the diagnosis. The use of AmniSure in women where the diagnosis is uncertain is likely to significantly change management, including reduced hospitalisation for women with preterm PROM.

Keywords
clinical tests, labour, placental alpha macroglobulin-1, preterm.

Placental a-microglobulin-1 to detect uncertain rupture of membranes in a European cohort of pregnancies

Abstract

Purpose: We evaluated the performance of the placental alpha-microglobulin-1 immunoassay (AmniSure, AT) in cervicovaginal secretions in patients with uncertain rupture of membranes (ROM) and investigated the influence of the examiners experience.

Methods: This prospective cohort study was performed in pregnant women (17–42 weeks of gestation) with signs of possible ROM. Evaluation included clinical assessment, examination for cervical leakage, Nitrazine test and measurement of the amniotic fluid index by ultrasound and AT. ROM occurrence was based on review of the medical records after delivery.

Results: 199 women were included. AT had a sensitivity of 94.4%; specificity of 98.6%; positive predictive value, 96.2%; negative predictive value, 98.0%. Clinical assessment showed a sensitivity of 72.2%; specificity of 97.8%; positive predictive value, 92.9%; negative predictive value, 90.6%. AT was more sensitive for diagnosing ROM (p = 0.00596) compared to clinical assessment, independent of the examiners experience. Furthermore, the sole use of AT reduced costs by 58.4% compared to clinical assessment.

Conclusions: AT was more sensitive compared to clinical assessment, independent of the examiners experience and gestational age. Our data extend its use in patients with uncertain ROM. Moreover, AT seems to be a cost-effective approach in the assessment of these patients.

Keywords
Amniotic fluid index (AFI), Placental alpha-microglobulin-1 immunoassay, Pregnancy, Rupture of membranes (ROM), Sensitivity, Specificity

Comparison of Two Rapid Strip Tests Based on IGFBP-1 and PAMG-1 for the Detection of Amniotic Fluid

Abstract

Our objective was to compare two rapid strip tests for the detection of amniotic fluid, based on the detection of insulin-like growth factor-binding protein-1 (IGFBP-1) and of placental a-microglobulin-1 (PAMG-1). Samples of amniotic fluid were taken in 20 pregnant women between 31 3/7 and 41 2/7 gestational weeks at elective cesarean section before delivery of the newborn. These samples were diluted with 0.9% saline solution in a dilution series down to concentrations of 1:320. Immunoassay strip tests were then compared in their ability to detect remaining concentrations of amniotic fluid. In 5 cases, both test methods showed the same results. In all remaining 15 cases, the test based on PAMG-1 proved to be superior by detecting amniotic fluid at least at one descending concentration below the test based on IGFBP-1. Thus, the rapid strip test based on PAMG-1 seems to be a more sensitive bedside test compared with the test based on IGFBP-1 for the detection of amniotic fluid.

Keywords
Amniotic fluid, bedside test, insulin-like growth factor-binding protein-1, placental a-microglobulin-1

Detection of Placental Alpha Microglobulin-1 versus Insulin-Like Growth Factor-Binding Protein-1 in Amniotic Fluid at Term: A Comparative Study

Abstract

We compared two biochemical tests of premature rupture of membranes (PROM) in vitro: Actim PROM (Medix Biochemica, Kauniainen, Finland), which detects insulin-like growth factor binding protein-1, and AmniSure (AmniSure International LLC, Cambridge, MA), which detects placental alpha microglobulin-1. Samples of amniotic fluid were collected during caesarean section in 41 patients. A dilution series was prepared and both tests were performed twice at each dilution. Sensitivity, detection limit, response time, and reproducibility of both tests were compared. Both tests’ sensitivity was 100% at dilution 1:10 and 1:20. AmniSure sensitivity was higher at dilution 1:40 and 1:80 (p < 0.05). In 29 of 40 cases, AmniSure had a lower detection limit than Actim PROM. AmniSure response times were shorter and reproducibility was higher than Actim PROM (p < 0.05). AmniSure had a lower detection limit of amniotic fluid than Actim PROM, with a shorter response time, a higher sensitivity, and a better reproducibility.

Keywords
Premature rupture of membranes, insulin-like growth factor binding protein-1, placental alpha-microglobulin-1, dilution

Examination Methods Used for Diagnosing Premature Rupture of Fetal Membranes

Abstract

Nearly one in ten pregnancies has a premature rupture of the fetal membranes (PROM). In nine out of ten cases, a diagnosis can be determined by clinical examination. In the remaining cases, it is necessary to make a reliable PROM diagnosis in order to make the appropriate management decisions. How do rapid biochemical tests perform here?

Comparative analysis of insulin-like growth factor binding protein-1 (IGFBP-1), placental alpha-microglobulin-1 (PAMG-1) and nitrazine test to diagnose premature rupture of membranes in pregnancy

Abstract

Purpose: To compare insulin-like growth factor binding protein-1 (IGFBP-1) (non-phosphorylated), placental alpha-microglobulin-1 (PAMG-1) and nitrazine test to diagnose premature rupture of membrane to allow gestation-specific management.

Methods: We recruited 100 women with signs or symptoms of premature rupture of membranes (PROM), between 17 and 37 weeks at a tertiary referral center.

Results: In 100 women in whom PAMG-1 was performed, sensitivity was 92.7%, specificity was 100%, positive predictive value (PPV) was 100% and negative predictive value (NPV) was 95.2%. IGFBP-1 was performed in 94 women, the sensitivity was 87.5%, specificity was 94.4%, PPV was 92.1% and NPV was 91.1%. In 98 women in whom nitrazine test was performed, the sensitivity was 85%, specificity was 39.7%, PPV was 49.3% and NPV was 79.3%.

Conclusion: PAMG-1 was the most accurate test in diagnosing rupture of membranes and had the highest sensitivity, specificity, PPVs and NPVs.

Keywords
Insulin-like growth factor binding protein-1 (non-phosphorylated); placental alpha-microglobulin-1; premature rupture of membranes.

Comparison of the diagnostic efficacy of the two rapid bedside immunoassays and combined clinical conventional diagnosis in prelabour rupture of membranes

Abstract

Objective: Diagnosis of prelabour rupture of membranes (PROM) may be challenging. Conventional diagnostic methods such as speculum examination, ferning pattern, and pH detection are not satisfactorily accurate. Two relatively new, commercially available rapid bedside immunoassay strip tests, for placental alpha microglobulin-1 (PAMG-1) and insulin-like growth factor binding protein-1 (ILGFBP-1), are alleged to be more accurate. We compared the diagnostic efficacy of PAMG-1 and ILGFBP- 1 immunoassay tests and combined conventional clinical diagnostic methods in PROM.

Study design: 167 pregnant women with signs and/or symptoms of PROM were prospectively evaluated with a combination of conventional clinical tests including speculum examination, nitrazine, ferning pattern, and pooling, in addition to PAMG-1 and ILGFBP-1 immunoassays. Differences in sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of the diagnostic methods were compared.

Results: Although the PAMG-1 assay was more accurate, the PAMG-1 immunoassay, ILGFBP-1 immunoassay, and combined conventional clinical diagnosis were, in fact, all highly accurate with no significant difference in sensitivity, specificity, PPV, NPV, or accuracy.

Conclusion: Both rapid bedside strip tests may be used in clinical practice with similar efficacy in diagnosing PROM, particularly as a backup when diagnosis is still in doubt following a combination of conventional diagnostic methods.

Keywords
Premature rupture of membranes, Prelabour ruptures of membranes, PAMG-1, ILGFBP-1

Contemporary Diagnosis and Management of Preterm Premature Rupture of Membranes

Abstract

Spontaneous rupture of membranes (ROM) is a normal component of labor and delivery. Premature ROM (PROM) refers to rupture of the fetal membranes prior to the onset of labor irrespective of gestational age. Once the membranes rupture, delivery is recommended when the risk of ascending infection outweighs the risk of prematurity. When PROM occurs at term, labor typically ensues spontaneously or is induced within 12 to 24 hours. The management of pregnancies complicated by preterm PROM (defined as PROM occurring prior to 37 weeks of gestation) is more challenging. Preterm PROM complicates 2% to 20% of all deliveries and is associated with 18% to 20% of perinatal deaths. Management options include admission to hospital, amniocentesis to exclude intra-amniotic infection, and administration of antenatal corticosteroids and broad-spectrum antibiotics, if indicated. This article reviews in detail the contemporary diagnosis and management of preterm PROM.

Keywords
Premature rupture of membranes, Preterm premature rupture of membranes, Preterm birth, Antibiotics, Antenatal corticosteroids

Technical innovations in clinical obstetrics

Abstract

Caring for a pregnant woman is both an enormous privilege and a weighty responsibility. To meet these demands, ob/gyns must constantly keep up with new innovations in their specialty and adapt new recommendations, when they are based on solid clinical research. Unfortunately, given the complexity of human pregnancy and the lack of an adequate animal model, the discipline of clinical obstetrics—unlike specialties like cardiology and neurology—is plagued by a dearth of such studies.

As you know, there are many situations in daily practice where we find ourselves in a "data-free zone," having to make recommendations and management decisions without the benefit of sound evidenced-based data. In those circumstances, clinical experience and the art of medical practice have to take over.

Nowhere is this more apparent than in clinical obstetrics, where many basic questions remain unanswered. While cardiologists measure changes in calcium flux within a single myocardial cell and nephrologists estimate changes in osmotic gradient along a single nephron, ob/gyns continue to debate such questions as: Why is the fetus head down at the end of pregnancy? What causes labor? How do we adequately monitor fetal well-being during labor?

Our purpose here is to review a series of devices and technical innovations that are currently under development to assist clinicians in caring for a pregnant woman and her fetus. Although none of these instruments are currently in routine clinical use, it is likely that they will find their way into clinical practice within the next few years.

Diagnosis of Premature Rupture of Membranes: Inspiration From the Past and Insights for the Future

Abstract

Objective: To review the diagnostic methods described to confirm premature rupture of membranes during pregnancy, and to assess their effectiveness in establishing the diagnosis.

Data Sources and Extraction: The medical literature was searched to identify all relevant studies and reviews on methods for diagnosis of membrane rupture published in English up to January 31, 2009. Medline and the Cochrane databases were searched, and reference lists in identified articles were also examined. Articles not available through journals’ online editions were retrieved by manual search.

Study Selection: We identified 71 original studies and reviews on diagnostic methods of chorioamniotic membrane rupture published in English. These articles were reviewed and results were summarized based on the diagnostic test assessed.

Conclusion: Recognition of the importance of and difficulties in confirmation of rupture of the chorioamniotic membranes pervades past and present obstetric publications. The subjectivity and poor sensitivity of early diagnostic techniques for confirmation of ruptured membranes sparked technical advancements using biochemical markers. None of these biochemical tests have gained popularity, although novel techniques involving placental markers such as placental alpha microglobulin-1 may provide a future solution to the problem of diagnosing chorioamniotic membrane rupture.

Are we ready for a new look at the diagnosis of premature rupture of membranes?

Abstract

Premature rupture of membranes is a significant contributor to preterm birth with its associated short- and long-term complications. The absence of a standard approach to its management places a burden on the clinicians’ ability to promptly and accurately diagnose premature rupture of membranes. For the last half century, there have been no significant changes in the way premature ruptured membranes is diagnosed. With the advent of newer, amniotic fluid-specific, noninvasive, and accurate markers, there is an opportunity to update the diagnosis of premature rupture of membranes.

Keywords
Ruptured fetal membranes, update, diagnosis

Guidelines for the management of spontaneous preterm labor: identification of spontaneous preterm labor, diagnosis of preterm premature rupture of membranes, and preventive tools for preterm birth

Keywords
Preterm labor, premature rupture or membranes, preventive tools

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

Abstract

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.

Keywords
Amniocentesis, amniorrhexis, amniotic fluid, diagnosis, dye test, fetal membranes, prelabor rupture of membranes, premature rupture.

The role of PAMG-1 protein and ultrasound cervicometry in detection of spontaneous preterm labour

Abstract

Context: Symptoms and signs of the premature labor (PTL) are very common in pregnancy; however symptoms and clinical evaluation alone do not accurately predict the probability of preterm delivery and the need for admission and treatment.

Objective: The objective of this study was to define the objective criteria based on the TVU examination and biochemical markers to predict probability of the PTL in order to reduce the number of unnecessary admissions.

Methods: Patients were assessed with the standard clinical examination, carditotocography and TVU. Placental a-microglobulin-1 (PAMG-1) was detected in the vaginal secretion with the PartoSure time-to-delivery (TTD) test (AmniSure Int, USA)

Patients: 49 women 290/7 - 346/7 GA with the symptoms of spontaneous preterm labor (10 contractions per hour median, interquartile range 5 - 13)

Intervention(s): All patients received the standard PTL management (corticosteroids, magnesium, tololytics)

Main Outcome Measure: Cervical length (CL) defined by TVU and the result of the PartoSure test were compared with the time-to delivery interval.

Results: Based on the CL all the patients were divided in 3 groups: <15 mm - 3 (6%), 15-30 mm - 42 (85%), >30 mm - 4 (8%). PartoSure test was positive in patients from the 1st group. 2 patients from the 1st group delivered in 7 days. 1 patient delivered in 18 days at term. In the 2nd group only 1 patient was PartoSure positive and she delivered within 7 days. No one else in the 2nd group delivered within 14 days. In the 3rd group no patients delivered within 14 days. The correlation between PartoSure test and the CL was (r = -0.47, p <0.05). The test predicted PTL within 14 days with 100% SN, 98% SP, 75% PPV and 100% NPV.

Conclusions: PartoSure test can be used to predict PTL probability in patients with the borderline CL (15-30 mm) and to support the further admission and treatment decision.

Comparison of a novel test for placental alpha microglobulin-1 with fetal fibronectin and cervical length measurement for the prediction of imminent spontaneous preterm delivery in patients with threatened preterm labor

Abstract

Objective: PartoSure is a bedside test for the prediction of time-to-spontaneous preterm delivery by the detection of placental alpha microglobulin-1 (PAMG-1). The objectives of this study were to further determine the test’s efficacy in predicting delivery within 7 or 14 days from testing, and to compare it with fetal fibronectin (fFN) and cervical length (CL) measurement by transvaginal ultrasound.

Study design: The study population consisted of 203 consecutively recruited women with singleton pregnancies between 200/7 and 366/7 weeks of gestation with symptoms of preterm labor, clinically intact membranes, and cervical dilatation of ≤ 3 cm. PartoSure and CL were performed on all patients and the test-to-spontaneous-delivery interval was calculated. In a sub-segment of patients, the QuikCheck fFN test was used.

Results: The sensitivities for PartoSure (n=203), fFN (n=66), and CL (n=203) for predicting imminent spontaneous preterm delivery within 7 days were 80%, 50%, and 57%, respectively. The specificities were 95%, 72%, and 73% for PartoSure, fFN and CL, respectively. The NPVs were 96%, 87%, and 89% for PartoSure, fFN and CL, respectively. The PPVs were 76%, 29%, and 30% for PartoSure, fFN and CL, respectively.

Conclusion: PAMG-1 detection by PartoSure is the single best predictor of imminent spontaneous delivery within 7 days compared to fFN and CL. In settings where CL is used as an initial screen, PartoSure has the greatest clinical utility in patients with CL between 15 and 35 mm. In situations where CL is not an initial screen, PartoSure is the most accurate test compared to fFN and CL.

Keywords
Cervical length (CL); fetal fibronectin (fFN); PartoSure Test; placental alpha microglobulin-1 (PAMG-1); preterm birth; preterm delivery; preterm labor (PTL); QuikCheck; transvaginal ultrasound (TVU).

Evaluation of a novel placental alpha microglobulin-1 (PAMG-1) test to predict spontaneous preterm delivery

Abstract

Objective: The PartoSure time-to-delivery (TTD) test (AmniSure International, Boston, MA, USA) is a newly available bedside test for the prediction of time to spontaneous preterm delivery via the detection of placental alpha microglobulin-1. The objective of this study was to determine the efficacy of the test in predicting imminent delivery in 7 or 14 days from the time of testing.

Methods: The study population consisted of 101 consecutively recruited pregnant women with singleton pregnancies between 20+0 and 36+6 weeks of gestation with symptoms of preterm labor, clinically intact amniotic membranes, and minimal cervical dilatation (≤ 3 cm). The PartoSure TTD test was performed on these patients and the test-to-spontaneous-delivery interval was calculated. Results: The PartoSure TTD test predicted spontaneous preterm delivery within 7 days with 90.0% sensitivity, 93.8% specificity, 97.4% negative predictive value (NPV), and 78.3% positive predictive value (PPV). The test predicted spontaneous preterm delivery within 14 days with 80% sensitivity, 96.1% specificity, 93.6% NPV, and 87.0% PPV.

Conclusion: A positive PartoSure TTD test in patients presenting with symptoms of preterm labor, intact membranes, and minimal cervical dilatation (≤3 cm) indicated spontaneous preterm delivery will occur within 7 days with a high degree of accuracy. A negative result indicated that spontaneous preterm delivery within 14 days is highly unlikely.

Keywords
PartoSure TTD test, placental alpha microglobulin-1, preterm birth, preterm delivery, preterm labor

The role of PAMG-1 protein and ultrasound cervicometry in detection of spontaneous preterm labour

Abstract

Context: Symptoms and signs of the premature labor (PTL) are very common in pregnancy; however symptoms and clinical evaluation alone do not accurately predict the probability of preterm delivery and the need for admission and treatment.

Objective: The objective of this study was to define the objective criteria based on the TVU examination and biochemical markers to predict probability of the PTL in order to reduce the number of unnecessary admissions.

Methods: Patients were assessed with the standard clinical examination, carditotocography and TVU. Placental a-microglobulin-1 (PAMG-1) was detected in the vaginal secretion with the PartoSure time-to-delivery (TTD) test (AmniSure Int, USA)

Patients: 49 women 290/7 - 346/7 GA with the symptoms of spontaneous preterm labor (10 contractions per hour median, interquartile range 5 - 13)

Intervention(s): All patients received the standard PTL management (corticosteroids, magnesium, tololytics) Main Outcome Measure: Cervical length (CL) defined by TVU and the result of the PartoSure test were compared with the time-to delivery interval.

Results: Based on the CL all the patients were divided in 3 groups: <15 mm - 3 (6%), 15-30 mm - 42 (85%), >30 mm - 4 (8%). PartoSure test was positive in patients from the 1st group. 2 patients from the 1st group delivered in 7 days. 1 patient delivered in 18 days at term. In the 2nd group only 1 patient was PartoSure positive and she delivered within 7 days. No one else in the 2nd group delivered within 14 days. In the 3rd group no patients delivered within 14 days. The correlation between PartoSure test and the CL was (r = -0,47, p <0,05). The test predicted PTL within 14 days with 100% SN, 98% SP, 75% PPV and 100% NPV.

PartoSure test can be used to predict PTL probability in patients with the borderline CL (15-30 mm) and to support the further admission and treatment decision.

Placental alpha-microglobulin-1 in combination with transvaginal ultrasound for prediction of preterm birth

Introduction

In patients with symptoms of preterm labor the measurement of the cervical length by transvaginal ultrasound alone has limited value regarding the prediction of preterm birth. The placental alpha-microglobulin-1 (PAMG-1) is a protein that can be found in high concentrations in the amniotic fluid and in lower concentrations in the vaginal secretion in patients with signs of preterm labor without rupture of membranes. This study aims to evaluate the clinical value of a novel point-of-care test for detection of PAMG-1 in the vaginal secretion. Patients, materials and methods: Patients with symptoms of preterm labor between 24 and 37 weeks of gestation were included into the study group. Gestational age-matched asymptomatic controls were included. Measurement of cervical length by transvaginal ultrasonography and a vaginal swab for the PAMG-1 point-of-care diagnostic kit were obtained. The test was performed according to the manufacturers recommendations. Primary endpoint was the time to delivery. The practicability of the PAMG-1 bedside test is the secondary endpoint. Results: The analysis showed a positive predictive value (PPV) and negative predictive value (NPV) of 100% and 69,5%, respectively, regarding the endpoint of birth within 7 days, and a PPV of 100% and NPV of 42.8% regarding birth within 14 days. These values were independent of cervical length measurements. The diagnostic kit for detection of PAMG-1 was easy to handle with no learning curve, and highly accepted by patients and staff.

Conclusions: The novel bedside PAMG-1 test has a higher positive predictive value compared to other commercially available bedside tests for preterm birth such as fetal fibronectine or IGFBP-1. Despite the low sensitivity and NPV, the test might be a clinically useful test if combined with cervical length measurement to predict preterm birth in patients with and without symptoms of preterm birth. Regarding the practicability the PAMG-1 test is easy and straightforward during routine examination.

An Audit of the Financial Burden of Admissions for Suspected Preterm Labour in a Peripheral Maternity Unit

Introduction

Preterm birth is defined as delivery occurring before 37 completed weeks gestation. It is a major obstetric and neonatal problem of the developed world. It is estimated to complicate up to 11% of pregnancies in Europe.(1)(2) A new test has been introduced which may be able to reliably predict the likelihood of preterm delivery within the following fortnight. National data from HIPE indicates that 􀁬false labour􀁺 is a significant cost to maternity hospital budgets nationally with 7599 patients admitted in 2011 with a mean length of stay of 1.2 days.(3) While many of these women may not be preterm it is indicative of the scale of financial costs to the Health Service of suspected preterm labour. A point of care test is now available which may prevent the unnecessary admission of this cohort to our maternity hospitals. Collection of data is necessary on the cost savings this test would be reasonably expected to yield in maternity hospitals. This may allow review in the future to see if the test, which in itself bears an economic cost, is being used appropriately and if clinicians are altering clinical practice based on its results. Only then can it be shown that definite economic value has been derived from this test and if the current resources and opportunity cost as a result of these current admissions can now be utilized elsewhere within the maternity hospital.

Objectives: To identify the volume of patients presenting to a peripheral maternity unit who would be suitable for a new point of care test to used to predict the onset of preterm labour and to assess the financial cost to the hospital and to the patient of admissions for suspected pre term labour. Study design and methods This was a retrospective audit of presentations with possible preterm labour. Cases were identified using the diary record of emergency presentations in addition to the transfer records over a 3 month period. Charts were reviewed and patients were contacted to obtain information regarding the impact on the patient and their partners. Patients were included if they presented with symptoms suggestive of preterm labour at 24-36+6 weeks gestation (e.g. pains, tightenings). Patients were excluded if they had confirmed PPROM, evident APH or cervical change suggestive of labour.

Discussion: As demonstrated by the available HIPE statistics admissions for 􀁬false labour􀁺 is a significant contributor to use of resources in maternity hospitals. Considering bed days and long term sick pay the total cost of these admissions to the excheqer was 61,230.40 euro in a small hospital over a 3 month period. Extrapolation of this figure over a year in this unit and further to all maternity units nationally the sum annual total would be astronomical. While no definitive figures exist nationally it is reasonable to assume that a significant percentage of these cases are preterm. Through this audit we have identified the significant financial burden these cases place on a peripheral maternity unit and also on referral centres through transfers which ultimately proved to have been unnecessary. The introduction of a new point of care test with a very high negative predictive value may act as a significant aide to the clinician in these cases and may reduce the opportunity cost of these cases. The case may be argued that cost cannot be saved by reducing admissions as hospital buildings and staff members are in existence regardless of the number of patients cared for. With increasing economic difficulty that is faced in the HSE and the possibility of further cutbacks, bed closures and staff redeployment careful resource management is increasingly important. We are currently employing this recently available commercial point of care test in conjunction with clinical assessment to identify a possible reduction in admissions /transfers. We plan to audit these cases prospectively, assessing the same parameters to see if it may result in a change in clinical practice .

Conclusion: This audit demonstrates the significant financial cost associated with admissions for suspected pre term labor in a peripheral hospital. By conducting this audit prior to the introduction of a new point of care test we have identified significant financial and human resource potential benefits of this test. This will allow us to monitor post introduction of the test if it has resulted in a change in clinical practice and the potential financial savings realised.

Evaluation of pamg-1 for the prediction of preterm birth in patients symptomatic of preterm labor

Abstract

Purpose: Traditional methods for assessing the risk of preterm birth in patients with threatened preterm labor (PTL) are inadequate. Several studies to−date have reported high positive (PPV) and negative predictive values (NPV) for the placental alpha microglobulin−1 (PAMG−1) test, commercially known as PartoSure, and have suggested it as a solution to address this problem. However, none of these studies have evaluated the test in a multi−national setting as diverse as the United Arab Emirates, which is represented by over 200 different countries.

Methods: PTL symptomatic patients between 24 and 37 weeks gestation, cervical dilatation Š3 cm, no sexual intercourse within 24 hrs of presentation, and no evidence of ROM were recruited. The PartoSure specimen was collected without a speculum prior to any other testing. The attending clinician remained blinded to its results when managing the care of the patient, as this was a prospective observational study. Sensitivity (SN), specificity (SP), PPV and NPV of PartoSure for predicting delivery within 7 and 14 days of presentation was calculated.

Results: 175 patients were recruited between April 2014 and April 2015. 24 (16%) were excluded from the final analysis for failure to meet study criteria; 13 of these 24 (i.e. 54% of excluded patients) were excluded due to either labor augmentation or a cesarean section delivery before active labor was diagnosed as regular contractions every 10 minutes or less, lasting more than 40 seconds, with cervical effacement more than 80 percent and dilation of 2cm (or 3cm). Therefore, 151 patients were included in the final analysis. The rate of delivery within 7 days of presentation was 6%. 71% of patients presented at <34 completed weeks of gestation. Over 50 nationalities were represented. For prediction of imminent spontaneous preterm birth, the PartoSure test had SP of 99% and 99%, SN of 67% and 54%, PPV of 75% and 88%, and NPV of 98% and 96%, for 7 and 14 days, respectively.

Conclusion: Our large study of over 150 patients from different nationalities, reinforces the important role of a predictor test, as the PAMG−1 test, in foreseeing preterm birth in symptomatic patients, particularly with respect to imminent spontaneous delivery within 7 and 14 days. The level of SP and NPV exceeds that of current methods allowing a significant reductions in the unnecessary administration of drugs and hospitalization in this patient group. Further studies are suggested to evaluate its use in combination with cervical length measurement.

Comparison of the fetal fibronectin (rapid ffn) and placental alpha microglobulin-1 (partosure) tests for predicting imminent spontaneous preterm birth in patients with threatened preterm labor

Abstract

Purpose: Up to 85% of patients presenting with signs of preterm labor are unnecessarily admitted andƒor treated due to the low specificity of traditional tests. The combinatory use of traditional tests and biochemical tests holds promise. The purpose of this investigation was to compare the novel PAMG−1 test (PartoSure) to the fFN test (Rapid fFN) for the prediction of imminent spontaneous preterm birth in patients with threatened preterm labor and a short cervix.

Methods: Pregnant women presenting between 22 and 34 weeks of gestation, clinically intact membranes, cervical dilation < 3 cm, and cervical length < 30 mm measured via transvaginal ultrasound (TVU) were invited to participate. fFN and TVU were performed as part of the standard of care at the hospital, while clinicians were blind to the PAMG−1 test results. Tests were evaluated for their ability to predict delivery within 7 and 14 days of presentation in all patients, as well as separately in patients with cervical length between 15 and 30 mm.

Results: A total of 36 patients enrolled after providing informed consent. One patient delivered via cesarean section without obvious indication that spontaneous birth was imminent. Thus, 35 patients were included in the final analysis. Average maternal age was 30 yrs and average gestational age at presentation was 29 weeks. While 77% of patients had a cervix of less than 25 mm, only 14% delivered within 7 days of presentation. Whereas fFN was positive in 40% patients, the PAMG−1 test was positive in only 11%. The positive predictive value (PPV) and negative predictive value (NPV) for predicting delivery within 7 days for the PAMG−1 test were 75% and 94%, respectively; the PPV and NPV for the fFN test for the same endpoint were 29% and 95%, respectively. The PPV and NPV for predicting delivery within 14 days for the PAMG−1 test were 75% and 90%, respectively; the PPV and NPV for the fFN test for the same endpoint were 29% and 90%, respectively. While both tests had NPVs of 100% for patients with cervical length between 15 and 30 mm, the tests had PPVs of 50% and 17%, PAMG−1 and fFN respectively.

Conclusion: The PAMG−1 test is more accurate than the fFN test at predicting imminent spontaneous delivery in symptomatic patients. Our data suggests that use of the PAMG−1 test in addition to cervical length measurement may reduce unnecessary admissions and drug administration by up to 72%.

Evaluation of a novel placental alpha microglobulin-1 (PAMG-1) test to predict spontaneous preterm delivery)

Abstract

Objective: The PartoSure™ time-to-delivery (TTD) test (AmniSure International, Boston, MA, USA) is a newly available bedside test for the prediction of time to spon- taneous preterm delivery via the detection of placental alpha microglobulin-1. The objective of this study was to determine the efficacy of the test in predicting imminent delivery in 7 or 14 days from the time of testing.

Methods: The study population consisted of 101 consec- utively recruited pregnant women with singleton preg- nancies between 20+0 and 36+6 weeks of gestation with symptoms of preterm labor, clinically intact amniotic membranes, and minimal cervical dilatation (  3 cm). The PartoSure™ TTD test was performed on these patients and the test-to-spontaneous-delivery interval was calculated. Results: The PartoSure™ TTD test predicted spontane- ous preterm delivery within 7 days with 90.0% sensitivity, 93.8% specificity, 97.4% negative predictive value (NPV), and 78.3% positive predictive value (PPV). The test pre- dicted spontaneous preterm delivery within 14 days with 80% sensitivity, 96.1% specificity, 93.6% NPV, and 87.0% PPV.

Conclusion: A positive PartoSure™ TTD test in patients pre- senting with symptoms of preterm labor, intact membranes, and minimal cervical dilatation (3 cm) indicated sponta- neous preterm delivery will occur within 7 days with a high degree of accuracy. A negative result indicated that sponta- neous preterm delivery within 14 days is highly unlikely.

Keywords
PartoSure TTD test; placental alpha micro- globulin-1; preterm birth; preterm delivery; preterm labor.

Preterm Labor and Birth Management: Recommendations from the European Association of Perinatal Medicine

Abstract

Preterm delivery (PTD) is one of the most common and most serious complications of pregnancy [3]. In Europe, preterm delivery is defined as delivery after 22 weeks completed but before 37 weeks of gestation [4-6]. In most parts of Europe , most pregnancies are dated using first trimester ultrasound, which means that the practice of validation of maturity at birth is rare. Practically, this means that it is adequate to stick to a terminology that relates to gestational age rather than maturity. The most relevant terminology for the condition should be PTD or preterm birth, rather than prematurity.

Keywords
Preterm labor, Birth management, Risk factors.

Comparison of PAMG-1 and phIGFBP-1 Tests for the Prediction of Preterm Delivery in Patients with Preterm Labor

Abstract

Objective: To compare PAMG-1 and phIGFBP-1 tests in predicting impending spontaneous preterm delivery within 7 days upon presentation in pregnant women with symptoms of preterm labor.

Study Design: From September 2014 to April 2015 women with singleton gestation, symptoms of preterm labor, GA 22 - 35, participated in this prospective cohort study upon admission. Recruited patients had intact membranes and a minimal cervical dilatation of ≤3 cm. Vaginal swabs for phIGFBP-1 and PAMG-1 were taken in addition to routine treatment. Biochemical test results were blinded and had no effect on management of patients.

Results: A total of 96 patients were screened for inclusion into the trial; 57 met the inclusion criteria for final analysis. The PAMG-1 test was positive in 5.7% of patients, while phIGFBP-1 test was positive in 29.8% of patients. The prediction of spontaneous preterm delivery within 7 days of admission in patients with a cervical length < 25 mm (30%), the PAMG-1 test and phIGFBP-1 test showed a SN of 100% and 100%; SP of 83.3% and 50.0%, (p ≤ 0.05); PPV of 71.4% and 45.5%; and NPV of 100% and 100%. 89.5% of women who received corticosteroids and 84.2% of women who received tocolysis did not go into preterm labor within one week.

Conclusion: Our study supports the high negative predictability of biochemical tests to rule out spontaneous preterm labor in patients with a short cervix. However, our study strongly suggests that the PAMG-1 test is more accurate for predicting imminent spontaneous preterm delivery as compared to phIGFBP-1. These findings can significantly reduce economic burden caused by unnecessary admission and treatment of patients suspected of preterm labor. Such a reduction in the use of corticosteroids and tocolytics would lead to a reduction in the short and long term health effects associated with the use of therapeutic drugs like corticosteroids, antibiotics and tocolytics.

Keywords
Preterm Labour/Labor, Preterm Birth, phIGFBP-1, Parto Sure, PAMG-1