Accuracy of fetal fibronectin for the prediction of preterm birth in symptomatic twin pregnancies: a pilot study

Preterm birth in low-middle income Countries

Preterm birth (PTB), remains a major cause of significant morbidity and mortality world-wide with about 12-15million preterm births occurring every year. Although the overall trend is decreasing, this is mainly in high-income countries (HIC). The rate remains high in low-and middle-income countries (LMIC) varying on average between 10 and 12% compared to 9% in HIC. The pathogenesis of PTB is complex and multifactorial. Attempts to reduce rates that have focused on PTB as a single condition have in general been unsuccessful. However, more recent attempts to phenotype PTB have resulted in targeted preventative approaches which are yielding better results. Prevention (primary or secondary) is the only approach that has been shown to make a difference to rates of PTB. These include identifying risk factors pre-pregnancy and during pregnancy and instituting appropriate measures to address these. In LMIC, although some approaches that have been shown to be effective in some HIC are adaptable, there is a need to involve stakeholders at all levels in utilizing evidence preferrably generated in LMIC to implement strategies that are likely to reduce the rate of PTB. In this review, we focus on prevention and how to involve policy makers in the process of applying evidence into policy that would reduce PTB in LMIC.

MicroRNA-21 as a potential biomarker for detecting esophageal carcinoma in Asian populations: a meta-analysis

Background

MicroRNA-21 (miR-21) is significantly expressed in a variety of cancers and could be used as a tumor biomarker. However, the results are varied, and no studies on the diagnostic usefulness of miR-21 in Asian esophageal cancer (EC) patients have been published. This meta-analysis was aimed at exploring whether miR-21 can be used as a diagnostic marker and assessing its effectiveness.

Methods

The relevant literature was identified in six main databases: Ovid MEDLINE, PsycINFO, PubMed MEDLINE, Embase, Web of Science, and the Cochrane Library. Two researchers independently selected the literature based on the inclusion and exclusion criteria, extracted data, and evaluated the risk of bias. The meta-analysis was carried out using Review Manager 5.4, Meta-Disc 1.4 and STATA 15.1 software. In the end, 987 patients from 12 different studies were included. Quality evaluation of diagnostic accuracy studies 2 (QUADAS-2) was used to examine the risk of bias.

Results

The pooled sensitivity (SEN) was 0.72 (95% CI [0.69-0.75]), the pooled specificity (SPE) was 0.78 (95% CI [0.75-0.81]), the pooled positive likelihood ratio (PLR) was 2.87 (95% CI [2.28-3.59]), the pooled negative likelihood ratio (NLR) was 0.36 (95% CI [0.31-0.43]), the pooled diagnostic odds ratio (DOR) was 10.00 (95% CI [7.73-12.95]), and the area under the curve 0.82 (95% CI [0.79-0.85]). A Deeks' funnel plot shows that there was no publication bias (P = 0.99).

Conclusion

Our findings suggest miR-21 might be the potential biomarker for detecting EC in Asian populations, with a good diagnostic value.

Self-reported pain scores as a predictor of preterm birth in symptomatic twin pregnancy: a retrospective study

BACKGROUND

To evaluate the self-reported pain scores as a predictor of preterm birth (PTB) in symptomatic twin pregnancy and to develop a nomogram for the prediction model.

METHODS

We conducted a retrospective study of 148 cases of symptomatic twin pregnancies before 34 weeks of gestation visited at Seoul national university hospital from 2013 to 2018. With other clinical factors, self-reported pain score was evaluated by the numerical rating scale (NRS) pain scores for pain intensity. By multivariate analyses and logistic regression, we developed a prediction model for PTB within 7 days. Using the Cox proportional hazards model, the curves were plotted to show the predictability of the PTB according to NRS pain score, while adjusting the other covariates.

RESULTS

Twenty-three patients (15.5 %) delivered preterm within 7 days. By a logistic regression analysis, higher NRS pain score (OR 1.558, 95 % CI 1.093-2.221, P < 0.05), shorter cervical length (OR 3.164, 95 % CI 1.262-7.936, P < 0.05) and positive fibronectin results (OR 8.799, 95 % CI 1.101-70.330, P < 0.05) affect PTB within 7 days. Using the variables, the area under the receiver operating characteristic curve (AUROC) of the prediction model was 0.917. In addition, we developed a nomogram for the prediction of PTB within 7 days.

CONCLUSIONS

Self-reported pain scores combined with cervical length and fetal fibronectin are useful in predicting impending PTB in symptomatic twin pregnancy.

Clinical and biochemical markers of spontaneous preterm birth in singleton and multiple pregnancies

AIM

The aim of this study was to compare the clinical characteristics of singleton and twin pregnancies that resulted in spontaneous preterm births (sPTB) and to evaluate the prognostic value of phosphorylated insulin-like growth factor binding protein-1 (phIGFB-1) and placental alpha macroglobulin-1(PAMG-1) for sPTB prediction in symptomatic women.

PATIENTS AND METHODS

The study included 420 women and included two parts. Firstly, we performed a retrospective cohort study comparing pregnancy and neonatal outcomes in 170 women with singleton pregnancies and spontaneous preterm birth before 37 weeks of gestation with 150 women with twin pregnancies who delivered at the same gestational age. In order to obtain the link between clinical and biochemical predictors of preterm labor we organized the second part of the research. The second part was a prospective observational study in 100 women with singleton and twin pregnancies between 24 and 33 + 6 weeks of gestation and symptoms of threatening preterm labor and intact membranes. We assessed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for phIGFBP-1 and PAMG-1 in terms of sPTB within 7 days and 14 days after testing.

RESULTS

The rate of preterm premature rupture of membranes was higher in singleton pregnancies (67.1 versus 42.8%, p = 0.034). Cervical shortening in multiples was diagnosed at an earlier mean gestational age than in singleton pregnancies (30.1 ± 4.3 versus 35.9 ± 3.1 weeks, p = 0.013). In the singleton pregnancies group, the rate of microbial cervical colonization and the rate of bacterial vaginosis were significantly higher than in twin pregnancies (49.4 versus 15.3%, p < 0.001; 32.9 versus 12.0%, p = 0.007, respectively). Premature twins had a longer oxygen dependency period, while the singletons were more predisposed to infectious morbidity. The study showed low sensitivity of phIGFBP-1 for sPTB, while the sensitivity of the PAMG-1 test was higher (sensitivity 60% and 90% within 7 days after testing and 50 versus 75% within 14 days after testing). Both tests showed a high NPV for sPTB (93.3% for phIGFBP-1 versus 98.9% for PAMG-1). The NPV for preterm labor in twins was also high for both tests (93% for phIGFBP-1 and 96% for PAMG-1).

CONCLUSION

Cervical shortening is the main risk factor of sPTB in women with twin pregnancies; sPTB among singletons is associated with ascendent infection, involving fetal membranes. The PAMG-1 test showed high PPV and NPV for sPTB in symptomatic women and could be a reliable prognostic tool in clinical obstetrics. High NPV was observed for phIGFBP-1 and PAMG-1 in twin pregnancies.

Accuracy of the combination of commercially available biomarkers and cervical length measurement to predict preterm birth in symptomatic women: A systematic review

An accurate prognostic method for preterm birth (PTB) could avoid unnecessary treatment(s) with potentially negative effects. The objective was to explore the prognostic accuracy of commercially available bedside cervicovaginal biomarker tests in combination with cervical length (CL) compared to CL measurement alone and/or a biomarker test alone, for PTB within 7 days after testing symptomatic women at 22-34 weeks. The MEDLINE, Cochrane, Embase and Web of Science databases were searched from inception to August 28th, 2019. Seven hundred and eight articles were identified and screened using Rayyan. Studies reporting on the predictive accuracy of combined tests compared to CL or biomarker alone for the prediction of PTB within 7 days of testing in symptomatic women with intact membranes were included. A piloted data extraction form was used. Direct comparisons of the prognostic accuracy of the combination test with CL measurement or a biomarker alone were done, as well as comparisons of prognostic accuracy of the included combination tests (indirect comparisons). Twelve articles were included (seven on fetal fibronectin, four on phosphorylated insulin-like growth factor binding protein-1, one comparing both). A variety of CL cut-offs was reported. The results could not demonstrate superiority of a combination method compared to single methods. Due to data scarcity and quality, the superiority of either predictive test for PTB, either combination or single, cannot be demonstrated with this systematic review. We recommend further research to compare available biomarkers.

Biochemical predictors of preterm birth in twin pregnancies: A systematic review involving 6077 twin pregnancies

In women with twin pregnancies biomarkers are not used to predict preterm birth in clinical practice. This systematic review assessed the risk of both spontaneous and iatrogenic preterm birth in twin pregnancies based on biochemical predictors. We searched the electronic databases from January 1990 to June 2019 without language restrictions. All studies on twin pregnancies where biochemical predictors and preterm birth were evaluated were included. We reported our findings as odds ratio (OR) with 95 % confidence intervals (CI) and pooled the estimates using random-effects meta-analysis for various predictor thresholds. From 12,623 citations, we included 33 studies involving 6077 pregnancies. The odds of preterm birth <28 weeks (OR 12.06, 95 % CI 4.90-29.70, I² = 0%), <32 weeks (OR 10.03, 95 % CI 6.11-16.47, I² = 0%), <34 weeks (OR 6.26, 95 % CI 3.85-10.17, I² = 30 %), <37 weeks (OR 5.34, 95 % CI 3.68-7.76, I² = 15 %) and delivery within 14 days of testing (OR 13.95, 95 % CI 4.33-44.98, I² = 0%) was increased among women with a positive fetal Fibronectin (fFN) test who were either symptomatic or asymptomatic for preterm birth. Similarly, higher odds of preterm birth was also seen among twin pregnancies asymptomatic for preterm birth with a positive fFN test at gestations <32 weeks (OR 10.54, 95 % CI 5.66-19.64, I² = 19 %), < 34 weeks (OR 8.07, 95 % CI 5.28-12.33, I² = 0%) and < 37 weeks (OR 6.21, 95 % CI 4.34-8.87, I² = 0%). As for other biomarkers, a significantly higher odds of preterm birth <37 weeks was seen among women with elevated maternal serum human Chorionic Gonadotrophin (mshCG) (OR 1.51, 95 % CI 1.07-2.13, I² = 0%), 25 Hydroxy Vitamin D level <75 nmol/l (OR 2.59, 95 % CI 1.35-4.95, I²=NA), positive phosphorylated Insulin-like Growth Factor Binding Protein-1 (phIGFBP-1) (OR 4.23, 95 % CI 1.97-9.09, I² = 0%) and in those with elevated Interleukin 8 (IL-8) (OR 3.13, 95 % CI 1.18-8.34, I²=NA). A higher odds of preterm birth at <34 weeks gestation was seen among women with maternal serum Alpha fetoprotein (AFP)>3.5 MoM (OR 2.35, 95 % CI 1.12-4.96, I²=NA) while higher odds of preterm birth at <32 weeks was seen among women with 25 Hydroxy Vitamin D level <75 nmol/l (OR 3.01, 95 % CI 1.26-7.19, I²=NA). Delivery within seven days of testing was significantly increased in women with a positive Matrix Metallo Protein-8 (MMP-8) test (OR 10.59, 95 % CI 3.70-30.29, I²=NA). Fetal Fibronectin is strongly associated with predicting preterm birth among women with twin pregnancies who are either asymptomatic or symptomatic for preterm birth as well as in those asymptomatic for preterm birth. Other biomarkers have shown a positive association in the prediction of preterm birth among women with twin pregnancies. Further studies are recommended to evaluate their role.

Single and repeat cervical-length measurement in twin gestation with threatened preterm labor

OBJECTIVE

To examine the effectiveness of single and repeat sonographic cervical-length (CL) measurement in predicting preterm delivery in symptomatic women with a twin pregnancy.

METHODS

This was a retrospective study of women with a twin gestation who presented with painful and regular uterine contractions at 24 + 0 to 33 + 6 weeks' gestation at the perinatal unit of the University Hospital of Tübingen, Tübingen, Germany between 2012 and 2018. CL was measured on transvaginal ultrasound at the time of admission and a few days later after cessation of contractions. Treatment included administration of tocolytics (usually oral nifedipine), for no more than 48 h, and administration of steroids if CL was ≤ 25 mm. Patients were clustered into five groups according to the CL measurement obtained at first assessment: < 10.0 mm; between 10.0 and 14.9 mm; between 15.0 and 19.9 mm; between 20.0 and 24.9 mm; and ≥ 25.0 mm. For each group, we calculated the test performance of CL measurement for prediction of preterm delivery within the subsequent 7 days and before 34 weeks' gestation. Regression analysis was used to evaluate the test performance of the second CL measurement for predicting preterm delivery within 7 days after the second assessment.

RESULTS

The study population consisted of 257 twin pregnancies, of which 80.2% were dichorionic diamniotic. Median maternal and gestational ages at the time of admission were 32.0 years and 29.9 weeks' gestation, respectively. Preterm birth within 7 days of admission occurred in 23 (8.9%) pregnancies, and 82 (31.9%) patients delivered prior to 34 weeks' gestation. Median CL for the entire study population was 17.0 mm. Delivery within 7 days after the first assessment occurred in 29.0%, 10.6%, 4.2%, 6.3% and 0% of women with CL < 10.0 mm, 10.0-14.9 mm, 15.0-19.9 mm, 20.0-24.9 mm and ≥ 25.0 mm, respectively. There was a weak, but significant, association between the CL measurement at the time of admission and the time interval between admission and delivery (interval = 27.9 + 0.58 × CL; P = 0.003, r = 0.184). CL was measured again after a median time interval of 3 (interquartile range (IQR), 2-5) days in 248 cases. Median second CL measurement was 17.0 (IQR, 11.5-22.0) mm. Delivery occurred within the subsequent 7 days after the second measurement in 25/248 (10.1%) cases. Binary regression analysis indicated that the first (odds ratio (OR), 0.895; P = 0.003) and second (OR, 0.908; P = 0.002) CL measurements, but not the difference between the two measurements (OR, 0.961; P = 0.361), were associated significantly with delivery within 7 days after the second measurement. Receiver-operating-characteristics (ROC)-curve analysis for the prediction of delivery within 7 days after the second assessment did not show a significant difference between the predictive performance of the first (area under ROC curve (AUC), 0.676 (95% CI, 0.559-0.793)) and the second (AUC, 0.661 (95% CI, 0.531-0.790)) measurement.

CONCLUSION

Sonographic measurement of CL can be helpful in predicting preterm delivery within 7 days of presentation in symptomatic women with a twin gestation; however, the test performance is relatively weak. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Quantitative fetal fibronectin to predict spontaneous preterm delivery after laser surgery for twin-twin transfusion syndrome

Our goal was to assess whether quantitative fetal fibronectin (qfFN) is associated with spontaneous preterm birth (sPTB) after laser surgery for twin-twin transfusion syndrome (TTTS). qfFN was collected within 24 hours before and after laser surgery. Aims were: (1) To determine if qfFN changed with operative fetoscopy; and (2) To estimate the number of patients needed to study the predictive value of qfFN for sPTB <28 and <32 weeks. Results are reported as median (range). Among 49 patients, there was no net difference in qfFN levels after laser surgery [0.0 ng/mL (-37 to +400), p = 0.6041]. However, patients with a qfFN increase >10 ng/mL were 19 times more likely to undergo sPTB at <28 weeks (OR = 19.5). We determined that 383 and 160 patients would be needed to achieve adequate statistical power for qfFN to be predictive of sPTB at a GA <28 weeks and <32 weeks, respectively. In conclusion, laser surgery did not alter the qfFN level within the entire cohort, but qfFN may be useful in identifying a subset of patients at increased risk of preterm delivery.

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.

The fetal fibronectin test: 25 years after its development, what is the evidence regarding its clinical utility? A systematic review and meta-analysis

Background: The identification of women at risk for preterm birth should allow interventions which could improve neonatal outcome. Fetal fibronectin, a glycoprotein which acts normally as glue between decidua and amniotic membranes could be a good marker of impending labour when its concentration in cervicovaginal secretions between 22 and 36 weeks of gestation is ≥50 ng/mL. Many authors worldwide have tested this marker with many different methodologies and clinical settings, but conclusions about its clinical use are mixed. It is time for a comprehensive update through a systematic review and meta-analysis.Methods: We searched PubMed, Cochrane Library, and Embase, supplemented by manual search of bibliographies of known primary and review articles, international conference papers, and contact with experts from 1-1990 to 2-2018. We have selected all type of studies involving fetal fibronectin test accuracy for preterm delivery. Two authors independently extracted data about study characteristics and quality from identified publications. Contingency tables were constructed. Reference standards were preterm delivery before 37, 36, 35, 34, and 32 weeks, within 28, 21, 14, or 7 d and within 48 h. Data were pooled to produce summary likelihood ratios for positive and negative tests results.Results: One hundred and ninety-three primary studies were identified allowing analysis of 53 subgroups. In all settings, none of the summary likelihood ratios were >10 or <0.1, thus indicating moderate prediction, particularly in asymptomatic women and in multiple gestations.Conclusions: The fetal fibronectin test should not be used as a screening test for asymptomatic women. For high-risk asymptomatic women, and especially for women with multiple pregnancies, the performance of the fetal fibronectin test was also too low to be clinically relevant. Consensual use as a diagnostic tool for women with suspected preterm labor, the best use policy probably still depends on local contingencies, future cost-effectiveness analysis, and comparison with other more recent available biochemical markers.