Cost-effectiveness of diagnostic testing strategies including cervical-length measurement and fibronectin testing in women with symptoms of preterm labor

Role of Platelet Activating Factor as a Mediator of Inflammatory Diseases and Preterm Delivery

Nearly 70% of preterm deliveries occur spontaneously, and the clinical pathways involved include preterm labor and preterm premature rupture of membranes. Prediction of preterm delivery is considered crucial due to the significant effects of preterm birth on health and the economy at both the personal and community levels. Although similar inflammatory processes occur in both term and preterm delivery, the premature activation of these processes or exaggerated inflammatory response triggered by infection or sterile factors leads to preterm delivery. Platelet activating factor (PAF) is a phosphoglycerylether lipid mediator of inflammation that is implicated in infections, cancers, and various chronic diseases and disorders including cardiovascular, renal, cerebrovascular, and central nervous system diseases. In gestational tissues, PAF mediates the inflammatory pathways that stimulate the effector mechanisms of labor, including myometrial contraction, cervical dilation, and fetal membrane rupture. Women with preterm labor and preterm premature rupture of membranes have increased levels of PAF in their amniotic fluid. In mice, the intrauterine or intraperitoneal administration of carbamyl PAF activates inflammation in gestational tissues, thereby eliciting preterm delivery. This review summarizes recent research on PAF as an important inflammatory mediator in preterm delivery and in other inflammatory disorders, highlighting its potential value for prediction, intervention, and prevention of these diseases.

Cervical Length Ultrasound for the Evaluation of Preterm Labor: A Survey of National Use and Review of Evidence

OBJECTIVE

The objective of this study was to survey national utilization of cervical length (CL) ultrasound on labor and delivery (L&D) for the evaluation of preterm labor (PTL) and identify provider attitudes and barriers to utilization.

STUDY DESIGN

Survey was emailed to Obstetrics and Gynecology Residency and Maternal-Fetal Medicine Fellowship program and advertised via links on obstetric-related Facebook interest groups. The survey was open from August 4, 2020 to January 4, 2021. Characteristics between respondents who did and did not report the use of CL ultrasound for PTL evaluation were compared with chi-square analysis.

RESULTS

There were 214 respondents across 42 states. One hundred and thirty-four respondents (63%) reported any use of CL in the evaluation of PTL and eighty (37%) denied it. There was a significant difference in practice location, practice type, delivery volume, and region between those who did and did not utilize CL ultrasound on L&D. Those who did use CL ultrasound were more likely to report no barriers to use (40 vs. 4%, p < 0.001). The most common barriers involved the availability of transvaginal ultrasound (31%), sterilization of transvaginal ultrasound probe (32%), limited availability of persons able to perform/interpret CL imaging (38%). Nineteen percent believed CL ultrasound had little/no utility in clinical practice. Those who did not use CL ultrasound in the evaluation of PTL were significantly more likely to report the feeling that there was little/no utility of CL ultrasound in clinical practice (37 vs. 7%, p < 0.001) and to report transvaginal ultrasound availability as barriers to use (63 vs. 12%, p < 0.001).

CONCLUSION

CL ultrasound is used nationally in PTL evaluation. However, significant barriers limit widespread adoption. These barriers can be addressed through the dissemination of information and practice guidelines, addition of CL ultrasound education in residency training and through CME opportunities after training, and providing support/resources/access for those looking to add this tool to their practice environment.

KEY POINTS

· In a national survey, 63% of obstetricians endorsed any use of cervical length (CL) ultrasound for preterm labor evaluation on labor and delivery.. · The most common barriers involved the availability of transvaginal ultrasound (31%), sterilization of transvaginal ultrasound probe (32%), limited availability of persons able to perform/interpret CL imaging (38%).. · Those who did not use CL ultrasound in the evaluation of PTL were significantly more likely to report the feeling that there was little/no utility of CL ultrasound in clinical practice and to report transvaginal ultrasound availability as barriers to utilization.. · Barriers to utilization of CL ultrasound for preterm labor evaluation can be addressed through practice guidelines, ultrasound education, and support for equipment/training necessary for use..

Assessment of cervical softening and the prediction of preterm birth (STIPP): protocol for a prospective cohort study

INTRODUCTION

Preterm birth (PTB) is among the leading causes of perinatal and childhood morbidity and mortality. Therefore, accurate identification of pregnant women at high risk of PTB is key to enable obstetric healthcare professionals to apply interventions that improve perinatal and childhood outcomes. Serial transvaginal cervical length measurement is used to screen asymptomatic pregnant women with a history of PTB and identify those at high risk for a recurrent PTB. Cervical length measurement, fetal fibronectin test or a combination of both can be used to identify women at high risk of PTB presenting with symptoms of threatened PTB. The predictive capacity of these methods can be improved. Cervical softening is a precursor of cervical shortening, effacement and dilatation and could be a new marker to identify women a high risk of PTB. However, the predictive value of cervical softening to predict spontaneous PTB still needs to be determined.

METHODS AND ANALYSIS

This is a single-centre, prospective cohort study, conducted at the Amsterdam University Medical Centers in the Netherlands. Cervical softening will be investigated with a non-invasive CE-marked device called the Pregnolia System. This device has been developed to evaluate consistency of the cervix based on tissue elasticity. Two different cohorts will be investigated. The first cohort includes women with a history of spontaneous PTB <34 weeks. These women undergo biweekly measurements between 14 and 24 weeks of gestation. The second cohort includes women with symptoms of threatened PTB. These women will receive the measurement once at presentation between 24 and 34 weeks of gestation. The primary outcome is spontaneous PTB before 34 weeks for women with a history of PTB and delivery within 7 days for women with threatened PTB. The minimum sample size required to analyse the primary outcome is 227 women in the cohort of women with a history of PTB and 163 women in the cohort of women with symptoms of threatened PTB. Once this number is achieved, the study will be continued to investigate secondary objectives.

ETHICS AND DISSEMINATION

The study is approved by the Medical Ethics Committee of Amsterdam UMC (METC2022.0226). All patients will give oral and written informed consent prior to study entry. Results will be disseminated via a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05477381.

Benefits of Premaquick® Combined Detection of IL-6/Total IGFBP-1/Native IGFBP-1 to Predict Preterm Delivery

We conducted a prospective double-blind study to compare two vaginal diagnostic methods in singleton pregnancies with threatened preterm labor (TPL) at the University Hospital of Clermont-Ferrand (France) from August 2018 to December 2020. Our main objective was to compare the diagnostic capacity at admission, in terms of positive predictive value (PPV) and negative predictive value (NPV), of Premaquick® (combined detection of IL-6/total IGFBP-1/native IGFBP-1) and QuikCheck fFN™ (fetal fibronectin) for delivery within 7 days in cases of TPL. We included 193 patients. Premaquick® had a sensitivity close to 89%, equivalent to QuikCheck fFN™, but a higher statistical specificity of 49.5% against 38.6% for QuikCheck fFN™. We found no superiority of Premaquick® over QuickCheck fFN™ in terms of PPV (6.6% vs. 7.9%), with NPV being equivalent in predicting childbirth within 7 days in cases of TPL (98.6% vs. 98.9%). Nevertheless, the combination of positive native and total IGFBP-1 and the combination of all three positive markers were associated with a higher PPV. Our results, though non-significant, support this combined multiple-biomarker approach to improve testing in terms of predictive values.

Cost-effectiveness of antenatal corticosteroids and tocolytic agents in the management of preterm birth: A systematic review

BACKGROUND

Preterm birth is a leading cause of neonatal mortality and morbidity, and imposes high health and societal costs. Antenatal corticosteroids (ACS) to accelerate fetal lung maturation are commonly used in conjunction with tocolytics for arresting preterm labour in women at risk of imminent preterm birth.

METHODS

We conducted a systematic review on the cost-effectiveness of ACS and/or tocolytics as part of preterm birth management. We systematically searched MEDLINE and Embase (December 2021), as well as a maternal health economic evidence repository collated from NHS Economic Evaluation Database, EconLit, PubMed, Embase, CINAHL and PsycInfo, with no date cutoff. Eligible studies were economic evaluations of ACS and/or tocolytics for preterm birth. Two reviewers independently screened citations, extracted data on cost-effectiveness and assessed study quality using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement.

FINDINGS

35 studies were included: 11 studies on ACS, eight on tocolytics to facilitate ACS administration, 12 on acute and maintenance tocolysis, and four studies on a combination of ACS and tocolytics. ACS was cost-effective prior to 34 weeks' gestation, but economic evidence on ACS use at 34-<37 weeks was conflicting. No single tocolytic was identified as the most cost-effective. Studies disagreed on whether ACS and tocolytic in combination were cost-saving when compared to no intervention.

INTERPRETATION

ACS use prior to 34 weeks' gestation appears cost-effective. Further studies are required to identify what (if any) tocolytic option is most cost-effective for facilitating ACS administration, and the economic consequences of ACS use in the late preterm period.

FUNDING

UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction (HRP), a cosponsored programme executed by WHO.

Availability and use of fetal fibronectin testing and transvaginal ultrasound for preterm labor evaluation in the United States

OBJECTIVE

Measure availability and use of fetal fibronectin (fFN) testing and transvaginal ultrasound to measure cervical length (TVCL) for symptomatic preterm labor (PTL) patients. Additionally, assess the presence and impact of PTL triage protocols.

STUDY DESIGN

Cross-sectional online survey among clinicians from 255 unique hospitals regarding prior 12-month practices (pre-COVID-19).

RESULTS

fFN testing was always available in 87% (221) of hospitals, while TVCL was always available in 69% (175) of hospitals. Utilization was lower: fFN specimens were often/always collected in 61% (156) of hospitals and TVCL was often/always performed in 43% (110) of hospitals. fFN testing was significantly more likely than TVCL to be available and used (p < .05). Written PTL protocols were available in 47% (121) of hospitals but not consistently followed.

CONCLUSION

The most accurate risk assessment approach for imminent spontaneous preterm birth is the implementation of a universal screening program for symptomatic patients, including fFN testing and TVCL.

Serum Copeptin Levels in Threatened Preterm Labor

We investigated maternal copeptin level's usefulness in prediction of preterm birth. Materials and methods: The study was comprised of 97 pregnant women hospitalized for threatened preterm labor and 35 healthy pregnant women without preterm labor. Serum copeptin were compared with likelihood of threatened preterm labor timing of delivery and time interval to delivery. Result: Copeptin level of threatened preterm labor group was higher than of control group [7.76(0.39-35.62) ng/mL, 6.23(1.64-36.88) ng/mL, respectively, p = .04]. Copeptin levels of women did not differ according to preterm or term birth [7.76(0.69-35.62) ng/mL, 6.73(0.39-36.88) ng/mL, respectively, p = .22). Quartiles of copeptin levels were not associated with risk status or preterm birth. Conclusions: Serum copeptin is higher in threatened preterm labor. It does not differentiate those with threatened preterm labor verses preterm birth.

Using quantitative fetal fibronectin to predict term labour onset in Australian rural women: A pilot study

BACKGROUND

Many women living in rural and remote Australia are required to travel large distances to birth in a hospital with maternity facilities, incurring considerable financial, social and emotional burden for them and their families. No studies to date have investigated the use of quantitative fetal fibronectin (qfFN) to predict term labour in asymptomatic pregnant women. A tool which is able to more accurately predict term labour has the potential to guide informed travel decision-making for women and healthcare professionals in rural and remote Australia.

AIM

The aim of this study is to determine if qfFN can reliably predict term labour in asymptomatic women from rural and remote areas.

MATERIALS AND METHODS

Thirty-nine women from rural Australia provided 71 fFN samples between June 2016 and October 2018, from 37 weeks' gestation, with at least one week between samples for those providing multiple samples. Days from fFN sampling until spontaneous onset of labour were recorded. Using generalised estimating equation modelling we examined the utility of fFN as a predictor for onset of labour at term after adjusting for confounders.

RESULTS

There was a small-to-moderate negative correlation (r_s -0.27, P < 0.05) between time until labour and fFN. Quantitative fFN was observed to be a significant predictor of time until labour after adjusting for confounding variables (P < 0.001).

CONCLUSION

fFN levels may play a role in predicting term labour in rural women; however, future studies with a larger sample size are required to validate the findings of our pilot study.

Guideline No. 401: Sonographic Cervical Length in Singleton Pregnancies: Techniques and Clinical Applications

OBJECTIVES

• To assess the association between sonography-derived cervical length measurement and preterm birth. • To describe the various techniques to measure cervical length using sonography. • To review the natural history of the short cervix. • To review the clinical uses, predictive ability, and utility of sonography-measured short cervix.

OUTCOMES

Reduction in rates of prematurity and/or better identification of those at risk, as well as possible prevention of unnecessary interventions.

INTENDED USERS

Clinicians involved in the obstetrical management or cervical imaging of patients at increased risk of a short cervix.

TARGET POPULATION

Women at increased risk of a short cervix or at risk of preterm birth.

EVIDENCE

Literature published up to June 2019 was retrieved through searches of PubMed and the Cochrane Library using appropriate controlled vocabulary and key words (preterm labour, ultrasound, cervix, cervical insufficiency, transvaginal, transperineal, cervical length, fibronectin). Results were restricted to general and systematic reviews, randomized controlled trials, controlled clinical trials, and observational studies. There were no date or language restrictions. Grey (unpublished) literature was identified through searching the websites of health technology assessment agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies.

VALUES

The evidence and this guideline were reviewed by the Diagnostic Imaging Committee of the Society of Obstetricians and Gynaecologists of Canada, and the recommendations were made and graded according to the rankings of the Canadian Task Force on Preventive Health Care (Online Appendix Table A1).

BENEFITS, HARMS, COSTS

Preterm birth is a leading cause of perinatal morbidity and mortality. Use of the sonographic technique reviewed in this guideline may help identify women at risk of preterm birth and, in some circumstances, lead to interventions that may reduce the rate of preterm birth. SUMMARY STATEMENTS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES): RECOMMENDATIONS (CANADIAN TASK FORCE ON PREVENTIVE HEALTH CARE GRADING IN PARENTHESES).

The efficacy of reduced-visit prenatal care model during the coronavirus disease 2019 pandemic: A protocol for systematic review and meta-analysis

BACKGROUND

While this reduced-visit prenatal care model during the COVID-19 pandemic is well-intentioned, there is still a lack of relevant evidence to prove its effectiveness. Therefore, in order to provide new evidence-based medical evidence for clinical treatment, we undertook a systematic review and meta-analysis to assess the efficacy of reduced-visit prenatal care model during the COVID-19 pandemic.

METHODS

The online literature will be searched using the following combination of medical subject heading terms: "prenatal care" OR "prenatal nursing" AND "reduced-visit" OR "reduce visit" OR "virtual visit." MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science will be searched without any language restrictions. A standard data extraction form is used independently by 2 reviewers to retrieve the relevant data from the articles. The outcome measures are as following: pregnancy-related stress, satisfaction with care, quality of care. The present study will be performed by Review Manager Software (RevMan Version 5.3, The Cochrane Collaboration, Copenhagen, Denmark). P < .05 is set as the significance level.

RESULTS

It is hypothesized that reduced-visit prenatal care model will provide similar outcomes compared with traditional care model.

CONCLUSIONS

The results of our review will be reported strictly following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria and the review will add to the existing literature by showing compelling evidence and improved guidance in clinic settings.

OSF REGISTRATION NUMBER

10.17605/OSF.IO/WYMB7.

Transvaginal ultrasound cervical length for prediction of spontaneous labor at term: A protocol for systematic review and meta-analysis

PURPOSE

To evaluate the predictive accuracy of transvaginal ultrasound (TVU) cervical length (CL) for spontaneous onset of labor in singleton gestation enrolled at term by a meta-analysis.

MATERIALS AND METHODS

This protocol established in this study has been reported following the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols. Web of Science, PubMed, EMBASE, and the Cochrane Library were searched for all clinical trials assessing the accuracy of TVU CL in prediction of spontaneous onset of labor in singleton gestations with vertex presentation who were enrolled at term until August 15, 2020. We will use a combination of Medical Subject Heading and free-text terms with various synonyms to search based on the eligibility criteria. Two investigators independently reviewed the included studies and extracted relevant data. The 95% confidence intervals (CIs) of was used as effect estimate. I-square (I2) test, substantial heterogeneity, sensitivity analysis, and publication bias assessment will be performed accordingly. Stata 15.0 and Review Manger 5.3 are used for meta-analysis and systematic review.

RESULTS

The results will be published in a peer-reviewed journal.

CONCLUSION

The results of this review will be widely disseminated through peer-reviewed publications and conference presentations. This evidence may also assess the accuracy of TVU CL in prediction of spontaneous onset of labor in singleton gestations with vertex presentation.

REGISTRATION NUMBER

INPLASY202080065.

Three biomarker tests to help diagnose preterm labour: a systematic review and economic evaluation

BACKGROUND

Preterm birth may result in short- and long-term health problems for the child. Accurate diagnoses of preterm births could prevent unnecessary (or ensure appropriate) admissions into hospitals or transfers to specialist units.

OBJECTIVES

The purpose of this report is to assess the test accuracy, clinical effectiveness and cost-effectiveness of the diagnostic tests PartoSure™ (Parsagen Diagnostics Inc., Boston, MA, USA), Actim^® Partus (Medix Biochemica, Espoo, Finland) and the Rapid Fetal Fibronectin (fFN)^® 10Q Cassette Kit (Hologic, Inc., Marlborough, MA, USA) at thresholds ≠50 ng/ml [quantitative fFN (qfFN)] for women presenting with signs and symptoms of preterm labour relative to fFN at 50 ng/ml.

METHODS

Systematic reviews of the published literature were conducted for diagnostic test accuracy (DTA) studies of PartoSure, Actim Partus and qfFN for predicting preterm birth, the clinical effectiveness following treatment decisions informed by test results and economic evaluations of the tests. A model-based economic evaluation was also conducted to extrapolate long-term outcomes from the results of the diagnostic tests. The model followed the structure of the model that informed the 2015 National Institute for Health and Care Excellence guidelines on preterm labour diagnosis and treatment, but with antenatal steroids use, as opposed to tocolysis, driving health outcomes.

RESULTS

Twenty studies were identified evaluating DTA against the reference standard of delivery within 7 days and seven studies were identified evaluating DTA against the reference standard of delivery within 48 hours. Two studies assessed two of the index tests within the same population. One study demonstrated that depending on the threshold used, qfFN was more or less accurate than Actim Partus, whereas the other indicated little difference between PartoSure and Actim Partus. No study assessing qfFN and PartoSure in the same population was identified. The test accuracy results from the other included studies revealed a high level of uncertainty, primarily attributable to substantial methodological, clinical and statistical heterogeneity between studies. No study compared all three tests simultaneously. No clinical effectiveness studies evaluating any of the three biomarker tests were identified. One partial economic evaluation was identified for predicting preterm birth. It assessed the number needed to treat to prevent a respiratory distress syndrome case with a 'treat-all' strategy, relative to testing with qualitative fFN. Because of the lack of data, our de novo model involved the assumption that management of pregnant women fully adhered to the results of the tests. In the base-case analysis for a woman at 30 weeks' gestation, Actim Partus had lower health-care costs and fewer quality-adjusted life-years (QALYs) than qfFN at 50 ng/ml, reducing costs at a rate of £56,030 per QALY lost compared with qfFN at 50 ng/ml. PartoSure is less costly than Actim Partus while being equally effective, but this is based on diagnostic accuracy data from a small study. Treatment with qfFN at 200 ng/ml and 500 ng/ml resulted in lower cost savings per QALY lost relative to fFN at 50 ng/ml than treatment with Actim Partus. In contrast, qfFN at 10 ng/ml increased QALYs, by 0.002, and had a cost per QALY gained of £140,267 relative to fFN at 50 ng/ml. Similar qualitative results were obtained for women presenting at different gestational ages.

CONCLUSION

There is a high degree of uncertainty surrounding the test accuracy and cost-effectiveness results. We are aware of four ongoing UK trials, two of which plan to enrol > 1000 participants. The results of these trials may significantly alter the findings presented here.

STUDY REGISTRATION

The study is registered as PROSPERO CRD42017072696.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Impact on perinatal health and cost-effectiveness of risk-based care in obstetrics: a before-after study

BACKGROUND

Obstetric health care relies on an adequate antepartum risk selection. Most guidelines used for risk stratification, however, do not assess absolute risks. In 2017, a prediction tool was implemented in a Dutch region. This tool combines first trimester prediction models with obstetric care paths tailored to the individual risk profile, enabling risk-based care.

OBJECTIVE

To assess impact and cost-effectiveness of risk-based care compared to care-as-usual in a general population.

METHODS

A before-after study was conducted using 2 multicenter prospective cohorts. The first cohort (2013-2015) received care-as-usual; the second cohort (2017-2018) received risk-based care. Health outcomes were (1) a composite of adverse perinatal outcomes and (2) maternal quality-adjusted life-years. Costs were estimated using a health care perspective from conception to 6 weeks after the due date. Mean costs per woman, cost differences between the 2 groups, and incremental cost effectiveness ratios were calculated. Sensitivity analyses were performed to evaluate the robustness of the findings.

RESULTS

In total 3425 women were included. In nulliparous women there was a significant reduction of perinatal adverse outcomes among the risk-based care group (adjusted odds ratio, 0.56; 95% confidence interval, 0.32-0.94), but not in multiparous women. Mean costs per pregnant woman were significantly lower for risk-based care (mean difference, -€2766; 95% confidence interval, -€3700 to -€1825). No differences in maternal quality of life, adjusted for baseline health, were observed.

CONCLUSION

In the Netherlands, risk-based care in nulliparous women was associated with improved perinatal outcomes as compared to care-as-usual. Furthermore, risk-based care was cost-effective compared to care-as-usual and resulted in lower health care costs.

The diagnostic value of fetal fibronectin testing in clinical practice

AIM

To evaluate the clinical management to withhold treatment for preterm labor in symptomatic women with an intermediate cervical length and negative fetal fibronectin (fFN) testing.

METHODS

A retrospective cohort study was performed in a tertiary care teaching hospital in the Netherlands. Pregnant women with a gestational age between 23⁺⁵ to 34⁺⁰ weeks, with the presence of regular uterine contractions accompanied by a cervical length between 15 and 30 mm and intact membranes, who underwent fFN testing were included to obtain the diagnostic value of fFN testing for preterm delivery within 7 days.

RESULTS

Fetal fibronectin testing has an extremely high negative predictive value (100%) and sensitivity (100%) for delivery within 7 days, in singleton and multiple pregnancies. However, specificity (64%) and positive predictive value (10%) of fFN testing in singleton pregnancies are low. Blood present on the fFN sample does not affect the reliability of the fFN test; the negative predictive value remains 100%.

CONCLUSION

Women with symptoms of early preterm labor, intact membranes, a cervical length between 15 and 30 mm and negative fFN testing do not deliver within 7 days. Administration of corticosteroids and tocolytics can safely be withhold. Furthermore, blood on the fFN sample does not change the reliability of the fFN test.

Evaluation of the effectiveness of foetal fibronectin as a predictor of preterm birth in symptomatic preterm labour women

BACKGROUND

The prediction of preterm birth (PTB) is important in the management of symptomatic preterm labour women. We evaluated the effectiveness of the foetal fibronectin (fFN) test for predicting PTB in symptomatic preterm labour women with consideration of physiologic changes in cervical length (CL) during pregnancy.

METHODS

This prospective study included 85 women with symptomatic preterm labour of a singleton pregnancy. Positive fFN was defined as a fFN level of > 50 ng/mL in cervicovaginal secretion, while a short CL was defined as that below 25th percentile at the corresponding gestational age. We evaluated effectiveness of the fFN test, CL, and the combination of these two tests, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), positive likelihood ratio (LR⁺), negative likelihood ratio (LR^-) to predict the PTB within 7 and 14 days of testing and PTB at < 34 and 37 weeks of gestation. We also present the odds ratios (ORs) of the test results, defining the women with both negative results as the reference group.

RESULTS

Of the 85 women, 31 (36.5%) showed a positive fFN and 44 (51.8%) had a short CL. PTB occurred within 7 and 14 days of testing and before 34 and 37 weeks of gestation in 17.6, 20.0, 23.5 and 49.4% of the women, respectively. The fFN and CL results showed low predictive effectiveness for the studied outcomes with LR⁺ (fFN, 1.5-1.9; CL, 1.0-1.5) and LR^- (fFN, 0.7; CL, 0.7-0.9). The combined use of fFN and CL could not improve these results (LR⁺, 1.4-2.3; LR^-, 0.7-0.9). However, the risk of PTB before 37 weeks was increased in women with positive fFN but not CL shortening compared to the reference group (odds ratio [OR], 3.8; 95% confidence interval [CI], 1.1-1.3). The risk of PTB before 34 weeks was increased in both positive fFN and CL compared to the reference group (OR, 8.1; 95% CI, 1.9-34.5).

CONCLUSION

Although, our approach could not improve the ability to predict PTB, it could identify women at risk for delivery before 34 or 37 weeks of gestation. Therefore, it could be used to manage women with symptomatic preterm labour.

The prediction of preterm delivery: What is new?

Preterm birth, defined as birth occurring prior to 37 weeks gestation, is a serious obstetric problem accounting for 11% of pregnancies worldwide. It is associated with significant neonatal morbidity and mortality. Predictive tests for preterm birth are incredibly important, given the huge personal, economic, and health impacts of preterm birth. They can provide reassurance for women who are unlikely to deliver early, but they are also important for highlighting those women at higher risk of premature delivery so that we can offer prophylactic interventions and help guide antenatal management decisions. Unfortunately, there is unlikely to be a single test for predicting preterm birth, but a combination of tests is likely to improve clinical prediction. This review explores the clinical utility of the currently marketed predictive tests for preterm birth in both singleton and multiple pregnancies, as well as discussing novel predictive tests that may be useful in the future.