Diagnosis Of Preterm Labor Research Articles

Diagnosis and Effective Management of Preterm Labor

Despite extensive research, we are still unable to diagnose, prevent and treat preterm labor. Monitoring efficacy of interventions that would allow this is largely biased by the inability to accurately identify true labor with the currently used crude technology. Progestin supplementation appears to be a promising approach to both preventing initiation of preterm labor and treating it once it is already established, given progesterone’s role in maintaining pregnancy as well as support from basic and clinical research. However, the questions on mechanisms of action, optimal progestin formulation, dose, route and timing of administration remain unanswered. We have established and reported noninvasive means to accurately monitor cervical ripening, by measuring collagen light-induced fluorescence (LIF) and myometrial contractility, by measuring uterine electromyo graphy (EMG). By accurately assessing the two components of parturition, cervical LIF and uterine EMG can help to identify effective prevention strategies and treatment of preterm labor.

The Effects of Progesterone Therapy on the Gestation Length and Reduction of Neonatal Complications in Patients who had Received Tocolytic Therapy for Acute Phase of Preterm Labor

BackgroundWhile tocolytic therapy can halt the process of delivery, some patients return before the 37th week of pregnancy with recurrence of preterm labor signs.ObjectivesThis study was designed to evaluate the efficacy of progesterone in the prolonging of gestation and reduction of neonatal complications.Material and MethodsIn a clinical trial in 2010, 110 singleton pregnant women admitted at Imam Reza Hospital, Mashhad, Iran, with the diagnosis of preterm labor were divided into three groups: 400 mg/d vaginal progesterone suppositories; 250 mg/w 17-alpha-hydroxyl-progestrone-caproate; and a control group with no additional treatment. After delivery, we assessed the duration between the first phases of labor to the recurrence of preterm labor. The neonatal complications, apgar score, birth weight, need for admission to NICU, and congenital malformations were compared between groups.ResultsThe mean gestational age was 34± 3 weeks in the first, 33.5 ± 3 weeks in the second and 32.5 ± 2 weeks in the control group. The duration of first phase of labor was 31 ± 17 days in the first, 36 ± 14 days in the second and 26 ± 22 days in the control group. The difference between study groups and the control group was significant (P < 0.005). The complications were lower in progesterone-receiving group in comparison to the control group.DiscussionThis study reveals that progesterone can significant reduce the rate of recurrent preterm labor and the several possible neonatal complications among women who had treated with tocolytics to suppress the acute phase.

Dysregulation of Diurnal Salivary Cortisol Production Is Associated with Spontaneous Preterm Delivery: A Pilot Study

Objectives: The purpose of this study was to evaluate whether the diurnal fluctuation of salivary cortisol and its overall diurnal secretion are associated with the length of gestation in patients who were admitted to the hospital with an assigned diagnosis of possible preterm labor (PL) at a gestational age of 28-33 weeks. Methods: In 22 patients, maternal saliva samples were collected for a cortisol assay 4 times per day (8 AM, 12 AM, 4 PM and 8 PM) on day 4 and day 6 after antenatal corticosteroid prophylaxis to prevent neonatal respiratory distress syndrome. Results: Eight patients who ultimately delivered before term (32.6 ± 1.7 gestation weeks) showed an inverted fluctuation of salivary cortisol on both days 4 and 6, morning cortisol levels being significantly lower than evening levels. In contrast, in 14 patients who delivered at term (39.5 ± 0.6 gestation weeks), the physiological diurnal fluctuation of salivary cortisol was maintained. In addition, a distinctive feature of women delivering before term was a significantly hampered salivary cortisol diurnal production measured on day 6. Conclusions: Corticoadrenal activity is dysregulated and anticipates very preterm delivery in women with an assigned diagnosis of possible PL.

Maternal serum interlukin-6 level in preterm labor

The aim of this study was to measure interleukin-6 (IL-6) levels in maternal serum of women undergoing preterm labor without a clear infection. Twenty two pregnant women with diagnosis of preterm labor who presented to the outpatient clinic of 19 Mayis University Faculty of Medicine from July 2011 through December 2011 were enrolled in the study group. Twenty two healthy pregnant women who were at the same gestational age as the study group were selected as the control group. Gestational age in the study and control groups varied from 24 weeks and 4 days to 34 weeks and 6 days. In the study group, 11 patients (50%) underwent preterm birth. Pregnant women in preterm labor were compared to healthy pregnant women with regards to serum IL-6 levels. No significant difference was found in the IL-6 levels of maternal serum between the 2 groups. In this study we have shown that there is no increase in lL-6 levels in patients undergoing preterm labor without clinical or biochemical infection signs.

The factors affecting depression, anxiety and perceived social support level of pregnant women who have the diagnosis of preterm labor

Gebelik doneminde depresyon ve kayginin, gebelik ve dogum komplikasyonlarini artirdigi, yeni doganin sagligini olumsuz etkiledigi, erken doguma, dusuk dogum agirligina ve intrauterin gelisme geriligine neden oldugu bildirilmistir. Arastirmanin amaci preterm eylem tanisi alan gebelerde kaygi, depresyon ve algilanan sosyal destek duzeyini etkileyen faktorleri belirlemektir. Arastirma tanimlayici tiptedir. Arastirma kapsamina Ege Universitesi Hastanesi Kadin Dogum Klinigi dogum servisi ve T.C. Saglik Bakanligi Dr. Ekrem Hayri Ustundag Kadin Hastaliklari ve Dogumevinin riskli gebe servisinde 01 Haziran - 31 Agustos 2010 tarihleri arasinda yatan 113 gebe alinmistir. Arastirma verilerinin toplanmasinda; arastirmacilar tarafindan literatur dogrultusunda hazirlanan birey tanitim formu, Beck Depresyon Olcegi (BDO), Durumluk Kaygi Olcegi (DKO) ve Surekli Kaygi Olcegi (SKO) ve Cok Boyutlu Algilanan Sosyal Destek Olcegi (CBASDO) yuz-yuze gorusme teknigi kullanilarak uygulanmistir. Veriler t-testi ve tek-yonlu ANOVA kullanilarak analiz edildi. Preterm eylem tanisi alan gebelerin BDO puan ortalamasinin 24.92±10.40, DKO puan ortalamasinin 45.81±8.75, SKO puan ortalamasinin 49.68±7.41 ve CBASDO puan ortalamasinin 49.15±15.90 oldugu belirlenmistir. Sonuc olarak, gebelerin depresyon puanlari orta duzeyde, kaygi duzeyi puanlari yuksek duzeyde ve algilanan sosyal destek puanlari da orta duzeydeydi. Hemsire ve ebelerin preterm eylem tanisi alan gebelerde depresyon ve anksiyeteyi degerlendirmesi ve sosyal destegi arttiracak girisimler planlamalari onerilmektedir.

Accurate preterm labor diagnosis using a CD55-TLR4 combination biomarker model

We previously demonstrated immune activation in the maternal peripheral circulation associated with preterm labor (PTL). There was an elevation in WBC mRNA of anti-inflammatory complement decay-accelerating factor (CD55) and the innate-immune response activating toll-like receptor 4 (TLR4). These findings suggested that collectively, these two molecules might serve as useful biomolecules to aid in the diagnosis of PTL. In this study, we used a combined marker approach to determine whether a dual marker model utilizing both CD55 and TLR4 mRNA levels to classify PTL would increase diagnostic accuracy compared to either molecule alone. Two methods were evaluated; a linear discriminant (LD) method and a distribution free (DF) method, in order to find the optimal linear combination of TLR4 and CD55 data to diagnose PTL accurately. Our results indicated that a combined CD55-TLR4 dual marker model could provide statistically significant improvements compared to CD55 or TLR4 single marker models for PTL classification performance.

Fetal sex and preterm birth

Rates of preterm birth vary between different populations and ethnic groups. Epidemiologic studies have suggested that the incidence of preterm birth is also higher in pregnancies carrying a male fetus; the male:female difference is greater in earlier preterm pregnancy. Placental or chorion trophoblast cells from pregnancies with a male fetus produced more pro-inflammatory TNFα in response to LPS stimulation and less anti-inflammatory IL-10 and granulocyte colony stimulating factor (G-CSF) than cells from pregnancies with a female fetus, more prostaglandin synthase (PTGS-2) and less prostaglandin dehydrogenase (PGDH). These results suggest that in the presence of a male fetus the trophoblast has the potential to generate a more pro-inflammatory environment. Maturation of the fetal hypothalamic–pituitary–adrenal axis and expression of placental genes, particularly 11β hydroxysteroid dehydrogenase-2 are also expressed in a sex dependent manner, consistent with the sex-biasing influences on gene networks. Sex differences in these activities may affect clinical outcomes of pre- and post-dates pregnancies and fetal/newborn wellbeing. These factors need consideration in studies of placental function and in the development of personalized strategies for the diagnosis of preterm labor and postnatal health.

Improving the screening accuracy for preterm labor: is the combination of fetal fibronectin and cervical length in symptomatic patients a useful predictor of preterm birth? A systematic review

Our objective was to systematically review the current medical literature to assess the accuracy of the combination of fetal fibronectin (fFN) plus ultrasound assessment of cervical length (CL) as screening tools for preterm labor and prediction of preterm birth (PTB), and to compare this to the traditional clinical method of digital cervical examination. We searched PubMed and Cochrane databases without date restriction using the key words "fibronectin" and "cervical length," limited to human studies published in English. In all, 85 studies were identified and supplemented by 1 additional study found through bibliographic search. Nine studies reported the association between fFN positivity plus CL measurement with PTB in women presenting with symptomatic uterine contractions. We conducted an analytic review of the sensitivity, specificity, positive predictive value, and negative predictive value of fFN plus CL for PTB. Further metaanalysis was not performed due to study heterogeneity, especially with respect to the range of gestational ages and variations in cutoff values for the diagnosis of short cervix. Although the clinical diagnostic methodology of preterm labor diagnosis by documenting uterine contractions plus cervical change is currently standard practice, a newer approach combining fFN and CL screening results in a higher sensitivity and positive predictive value for PTB risk while maintaining high negative predictive value. We conclude that this combined screening approach yields useful information regarding short-term risks that can be used to guide acute management, and effectively identifies a population at low risk in whom expensive and potentially dangerous interventions could be avoided.

The frequency and clinical significance of intra-amniotic inflammation in women with preterm uterine contractility but without cervical change: do the diagnostic criteria for preterm labor need to be changed?

Objective: The objective of this study was to determine the frequency and clinical significance of intra-amniotic inflammation in patients with preterm increased uterine contractility with intact membranes but without cervical change. Methods: Amniocentesis was performed in 132 patients with regular uterine contractions and intact membranes without cervical change. Amniotic fluid was cultured for bacteria and mycoplasmas and assayed for matrix metalloproteinase-8 (MMP-8). Intra-amniotic inflammation was defined as an elevated amniotic fluid MMP-8 concentration (>23 ng/mL). Results: (1) Intra-amniotic inflammation was present in 12.1% (16/132); (2) Culture-proven intra-amniotic infection was diagnosed in 3% (4/132) of patients without demonstrable cervical change on admission or during the period of observation; and (3) Patients with intra-amniotic inflammation had significantly higher rates of preterm delivery and adverse outcomes, and shorter amniocentesis-to-delivery intervals than those without intra-amniotic inflammation (P < 0.05 for each). Adverse outcomes included chorioamnionitis, funisitis, and neonatal death. Conclusion: Intra-amniotic inflammation was present in 12% of patients with regular uterine contractions without cervical change, while culture-proven intra-amniotic infection was present in 3%. The presence of intra-amniotic inflammation was a significant risk factor for adverse neonatal outcomes. These observations question whether cervical changes should be required for the diagnosis of preterm labor, because patients without modifications in cervical status on admission or during a period of observation are at risk for adverse pregnancy outcomes.

Évolution de la synchronisation des signaux de l’électromyogramme utérin en fonction du terme de grossesse, et intérêt pour la détection précoce de la menace d’accouchement prématuré

ObjectivesOur study focuses on the analysis of the uterine electromyogram recorded on women during pregnancy. We were interested in evaluating the synchronization of this electrical signal at various terms in order to follow evolution of synchronization as labor approaches. This study attempts to deepen our understanding of the myometrial maturation close to labor and to provide reliable parameters for improving preterm labor diagnosis. Patients and methodsWe performed a prospective study by recording the electrical signals of physiological uterine contractions (causing no delivery) on 16 pregnant women. We then calculated the non-linear correlation coefficient h2 to estimate synchronization between EMG signals collected for each contraction. We expressed the results by grouping synchronization values by class of term in order to study the evolution of this coefficient along gestation. This study has been approved by the ethical committee of our hospital. ResultsOur results show a non-significant increase of the h2 value along term. There is however a trend towards an increase of the synchronization of EMG signals as labor approaches but not enough to conclude definitively. Discussion and conclusionWith a confirmation of the increase of h2 along term, the study of the synchronization of uterine electrical activity could be an important clue to support the notion of myometrial maturation close to labor. Synchronization analysis could also be a promising parameter for reliable diagnosis of preterm labor.

A STUDY OF RISK FACTORS AND PERINATAL OUTCOME IN PRETERM LABOUR AT TERTIARY CARE HOSPITAL

Background- Preterm labour is a common complication that contributes significantly to high perinatal morbidity and mortality. In India, the reported incidence of preterm labour is 10-15 percent. Premature babies are at risk of many immediate and long term complications. Material and Methods- Prospective observational study of various risk factors responsible for preterm labour and the perinatal outcome was done in 125 women, over one year period at tertiary care centre in rural area. Diagnosis of preterm labour was done by ACOG 197 criteria. Results-The incidence of preterm labour was 13.2%. It was observed that 95% women were unbooked cases from poor socio-economic class, staying in a rural area. Fifty percent cases had pregnancy duration of 32 to 34 weeks. Sixty percent cases had some associated risk factor responsible for preterm labour. Antepartum haemorrhage (22.53%) over distension of the uterus (16.90%), hypertension and maternal anaemia were common risk factors. Perinatal mortality in the study group was 42.4%. Early neonatal deaths accounted for 50% of the perinatal mortality. Antepartum haemorrhage, maternal anaemia, hepatitis, obstructed labour, and fetal congenital anomalies were common causes of stillbirths, where as respiratory distress, birth asphyxia and septicaemia were common causes of early neonatal deaths. Neonatal mortality was 100% in the babies with birth weight less than 1000 grams. Neonatal mortality was 63.33% in babies born before 31 weeks of gestation. Conclusion- Early detection of high-risk factors, appropriate intervention, institutional delivery and good neonatal care backup facilities can improve the outcome of preterm labour.

Cervical Length Measurement in Obstetrics: From Academic Luxury to Clinical Practice

ABSTRACT Preterm birth is the main cause of perinatal mortality and morbidity and can be very costly to the healthcare system. Although improvements in neonatal care have led to higher survival of very premature infants, there is a need for the development of a sensitive method with which to identify women at high risk of preterm delivery and find an effective strategy for the prevention of preterm labor.1 Considering the increased incidence of preterm birth, it has become more important now to be able to early diagnose this problem. The measurement of cervical length to predict the risk of preterm birth can be extremely useful in diagnosing this condition. The use of transvaginal ultrasound in measuring cervical length is safe, reliable and well accepted by women.2 The use of vaginal progesterone has shown to be effective in the prevention of preterm delivery in women with short cervix. Tocolytics are used to delay labor for a minimum of 24 to 48 hours3 for up to 1 week but they have not shown to improve neonatal outcomes and most have undesirable side effects. Steroids can assist with fetal lung maturity when the diagnosis of preterm labor is made,3 they can be used unnecessarily when preterm labor is misdiagnosed. The measurement of cervical length can also be helpful in patients with preterm premature rupture of membrane and in patients with the presence of amniotic fluid (AF) sluge.4 Therefore, performing cervical length measurements in all pregnant women and use it as a screening tool at around 20 weeks of pregnancy to identify patients at high risk of preterm labor can assist with true diagnosis. There is a great expectation from cervical assessment and subsequent addition of progesterone to reduce preterm birth and have better neonatal outcomes. The aim of this review is to bring forward evidence that highlights the importance of performing cervical length measurement in midpregnancy in all pregnant women to predict the risk of preterm birth. Medline, PubMed, MD Consult and Science Direct were searched using the terms cervical length measurement, ‘preterm delivery’, ‘amniotic fluid sludge’ and ‘treatment for preterm birth’. How to cite this article Ahmed B, Hasnani Z. Cervical Length Measurement in Obstetrics: From Academic Luxury to Clinical Practice. Donald School J Ultrasound Obstet Gynecol 2012;6(1):93-96.

470: Betamethasone for threatened preterm labor: a clinical review at a single academic medical center

To review timing of administration of betamethasone for pregnancies with threatened preterm labor or advanced cervical dilation A retrospective cohort study of patients who received betamethasone (BMZ) for the reduction of preterm morbidity was performed between July 1, 2004 and June 30, 2009. Rescue or repeat courses of BMZ were not administered. The Northwestern University Electronic Database Warehouse was used to identify all patients who received BMZ. Each identified patient was assigned a diagnosis of preterm labor (PL) if they received tocolysis or delivered imminently. Advanced cervical dilation (ACD) was defined as those patients who did not require tocolysis or deliver imminently. PL and ACD groups were stratified by the cervical dilation and cervical effacement at the time BMZ was administered. The primary outcome was the interval between the gestational age (GA) at BMZ administration and the GA at delivery. NICU length of stay and the percentage of patients who delivered within 7 days of BMZ administration were secondary outcomes. All data was analyzed with the Kruskal-Wallis test. Three hundred and fifty six patients received BMZ for PL and 247 patients for ACD. The median interval between administration of BMZ and delivery was 35 days for preterm labor and 47 days for advanced 28 days (p<0.0001). Compared to ACD patients, PL patients were more dilated (2 vs. 1 cm, p<0.0001) and more effaced (1.5 vs. 2 cm, p<0.0001) at the time of BMZ administration. There was no significant difference in the median NICU length of stay between PL and ACD patients. Only patients who presented with PL and were 3.5+ cm dilated or completely effaced delivered within 7 days of BMZ administration (p<0.005). For ACD patients, only those who were 0.5 cm effaced or less delivered within 7 days of BMZ administration (p<0.005). The interval between BMZ administration and delivery at our institution is greater than 7 days for patients who present with PL or ACD. Improvements need to be made in order to better triage patients who present with threatened PL or ACD. Tabled 1

Application of proteomic models for the diagnosis of inflammatory and non-inflammatory preterm delivery

To establish the serum proteomic models for the identification of premature delivery with inflammation or non-inflammation. The laboring patients from 2008 to 2010 at our hospital were divided into 5 groups according to placental pathology, including inflammatory preterm group, non-inflammatory preterm group and blind test group (n = 50 each). The control group was normal full-term. The preterm models with or without inflammation were established by the methods of SELDI-TOF-MS (matrix-assisted laser desorption/ionization-time of flight-mass spectrometry) and bioinformatics. And statistical analysis was performed after a blind test. Then differential protein fingerprints were compared and analyzed. A total of 36 different proteins were harvested after a comparison of inflammatory preterm and control groups. The model was established by eight markers. The rates of specificity, sensitivity, positive predictive value and negative predictive value were 80.85%, 84.44%, 93.33% and 46.67% respectively. Fifteen different proteins existed between non-inflammatory preterm and control groups. There were 4 marker proteins. The rates of specificity, sensitivity, positive predictive value and negative predictive value were 75.68%, 64.44%, 80.00% and 66.67% respectively. Different marker proteins existed between the identification models of inflammatory preterm labor and inflammatory full-term. Different serum proteomic models may be used for the diagnosis of preterm labor and the differentiation of preterm labor with or without inflammation. And different proteins are expressed during different stages of pregnancy with chorioamnionitis.

The Diagnosis and Natural History of False Preterm Labor

To estimate the natural history of pregnancies in women who present with preterm labor symptoms and who are sent home with a diagnosis of false labor. A prospective observational study of women with singletons and intact membranes who presented to triage between 24 0/7 and 33 6/7 weeks of gestation with preterm labor symptoms and cervical dilation less than 2 cm was conducted. Women sent home with a diagnosis of false preterm labor were analyzed against a comparable general obstetric population delivered during the same time period. The primary outcome was delivery before 37 weeks of gestation. Secondary outcomes included the interval between presentation and delivery, as well as maternal and neonatal outcomes. Of the 843 women who met inclusion criteria, 690 (82%) were sent home with a diagnosis of false preterm labor and 153 (18%) were admitted to labor and delivery. When analyzed compared with a comparable general obstetric population, women sent home had a similar rate of birth before 34 weeks of gestation (2% compared with 1%, P=.28) but a higher rate of birth between 34 and 36 weeks of gestation (5% compared with 2%, P<.001). There was no difference in neonatal mortality (0% compared with 0.3%, P=.18). Women with cervical dilation of 1 cm at discharge were more likely to deliver before 34 weeks of gestation compared with nondilated women (5% compared with 1%, P=.02); however, 89% of the 1-cm group delivered more than 21 days after presentation. Women sent home with a diagnosis of false preterm labor are not at increased risk for early preterm birth or neonatal mortality; however, they are at increased risk for late preterm birth. II.

A case of spontaneous rupture of a uterine superficial varicose vein in midgestation

A 25-year-old gravida two, nulliparous pregnant woman complained of a sudden onset of severe pain in the right lateral abdominal area and went to hospital at 28 weeks and 5 days' gestation. Since cyclic uterine contractions were observed, a diagnosis of preterm labor was made and tocolysis was carried out by the continuous venous infusion of ritodorine. She was transferred to Hamamatsu University Hospital and an emergency cesarean section was carried out due to non-reassuring fetal status. A hemoperitoneum of 850 mL was observed in the peritoneal cavity and an immature male baby weighing 1140 g was born. There was bleeding from a ruptured superficial varicose vein in the right lateral portion of the uterus, which was stopped by compression and the attachment of oxidized cellulose cotton. The clinical management and differential diagnosis were discussed.

The Role of Human Decay-Accelerating Factor in the Pathogenesis of Preterm Labor

Complement activation is thought to contribute to the pathogenesis of preterm labor (PTL). Decay-accelerating factor (DAF) is a natural complement pathway inhibitor. Our hypothesis was that DAF expression on maternal white blood cells (WBCs) in women with preterm labor is elevated compared with women with no preterm labor. Our secondary objective was to determine if differences in upregulation of DAF levels correlated with clinical outcomes. Serial blood samples were obtained from 30 patients with a clinical diagnosis of PTL and a control group of 30 pregnant individuals (same gestational age range) to determine DAF expression in peripheral WBCs in both groups. DAF expression was higher in women with PTL (less than 37 weeks) compared with the control group without PTL. Subjects with PTL who delivered before 34 weeks had less DAF expression and different kinetics of expression compared with those carrying pregnancies beyond 34 weeks. These data suggest that women with a clinical diagnosis of preterm labor have increased DAF expression on peripheral WBCs. Furthermore, it appears that failure to elevate DAF expression is associated with a risk of early premature delivery.

Fetal fibronectin as a predictor of spontaneous preterm birth: a European perspective

Preterm birth (PTB) is estimated to account for 6–10% of all births worldwide with 13 million PTBs occurring annually and 1 million resulting in death. The diagnosis of spontaneous preterm labor and accurate prediction of preterm delivery is notoriously difficult. Identification of effective risk assessment markers can potentially improve outcomes by enabling targeted therapy while allowing efficient use of resources and avoiding unnecessary interventions. Advances in perinatal medicine have not reduced PTB and effective measures that improve outcome are yet to be established. However, considerable progress has been made in the development of accurate methods (fetal fibronectin and cervical length assessment) to predict PTB in both symptomatic and asymptomatic high-risk women. The excellent negative predictive value of fFN has the ability to facilitate decision-making regarding admission, in utero transfer, administration of antenatal corticosteroids and/or tocolysis and has been shown to be cost-effective. This review describes the European perspective on the use of fFN and describes ongoing European clinical studies, which are appropriately designed with meaningful endpoints, which will undoubtedly facilitate a better understanding of test accuracy and cost-effectiveness within different populations.

Contingent Use of Fetal Fibronectin Testing and Cervical Length Measurement in Women With Preterm Labour

ObjectiveTo evaluate the contingent use of fetal fibronectin (fFN) testing and cervical length (CL) measurement to predict preterm delivery, and to validate the use of phosphorylated IGFBP-1 as a predictor of preterm delivery. MethodsWe recruited 71 women with a clinical diagnosis of preterm labour between 24 and 34 weeks, and tested for the presence of fFN and IGFBP-1 in the cervicovaginal secretions of all women immediately before CL measurement. ResultsAmong the 66 women with complete outcome, four were excluded from the final analysis as two had assessment for fFN but no CL measurement, and another two had CL measured but no screening for fFN. Among 62 women with complete results, the mean gestational age at recruitment was 29.4 ± 2.5 weeks. Six women (9.6%) delivered within two weeks of assessment, and 14 (22.5%) delivered before 34 weeks. A positive fFN test resulted in a sensitivity of 83%, a specificity of 84%, a positive predictive value of 36%, and a negative predictive value of 98% for delivery within two weeks; for CL < 25 mm, these figures were 50%, 52%, 10%, and 91%, respectively, and for a positive IGFBP-1, they were 17%, 93%, 20%, and 91%, respectively. A policy of contingent use of fFN (in which the test was assumed to be positive if CL ≤ 15 mm, and fFN was only measured if the CL was between 16 and 30 mm) gave sensitivity, specificity, positive and negative predictive values of 80%, 61%, 17%, and 97%, respectively for delivery within two weeks. Using this contingent use protocol, only one third of women needed fFN screening after CL measurement. ConclusionIn this study, IGFBP-1 screening did not predict preterm delivery and fFN screening provided the best predictive capacity. A policy of contingent use of testing for fFN after CL measurement, or contingent use of CL measurement after fFN screening (depending on available resources) is a promising approach to limit use of resources.

493: Elevated serum levels of matrix metalloproteinase-1, interstitial collagenase, is a useful adjunctive marker in the clinical diagnosis of preterm labor

493: Elevated serum levels of matrix metalloproteinase-1, interstitial collagenase, is a useful adjunctive marker in the clinical diagnosis of preterm labor