Fetal fibronectin as a predictor of preterm birth in patients with symptoms: a multicenter trial

Clinical application of amino-terminal pro-brain natriuretic peptide concentration in amniotic fluid for the prediction of preterm birth in symptomatic women

BACKGROUND

Preterm birth accounts for 60% to 80% of neonatal mortality. Approximately one-third of preterm births are caused by the spontaneous onset of preterm labor. Nevertheless, 70% to 90% of women diagnosed with preterm labor will not deliver within 7 days. Thus, many women will be unnecessarily treated by preterm labor with risk medications. Better tools are needed to categorize women in preterm labor into high or low risk of preterm delivery.

OBJECTIVE

This study aimed to evaluate the amino-terminal pro-brain natriuretic peptide concentration in the amniotic fluid as a prognostic test to predict the risk of delivery within 48 hours or 7 days and before 34 0/7 or 37 0/7 weeks of gestation in women in preterm labor.

STUDY DESIGN

A total of 102 pregnant women presenting signs and symptoms of spontaneous preterm birth (22 0/7 to 34 0/7 weeks of gestation) were included. Amniotic fluid was obtained by amniocentesis, and amino-terminal pro-brain natriuretic peptide concentration was measured. Below normal concentration was defined as <0.5 multiples of the median of the standard curve according to gestational age. The risk of preterm delivery was estimated according to normal or lower-than-normal amino-terminal pro-brain natriuretic peptide concentrations. The predictive capacity of the test (below normal amino-terminal pro-brain natriuretic peptide concentration) was evaluated to identify spontaneous preterm birth at 48 hours or 7 days from amniocentesis and less than 34 0/7 or 37 0/7 weeks at delivery.

RESULTS

For the outcome delivery within 48 hours, lower-than-normal amino-terminal pro-brain natriuretic peptide concentration had 94.6% sensitivity, 73.8% specificity, 96.0% negative predictive value, 3.61 positive likelihood ratio, and 0.07 negative likelihood ratio. For the outcome delivery within 7 days, the test had 93.9% sensitivity, 88.7% specificity, 94.0% negative predictive value, 8.31 positive likelihood ratio, and 0.07 negative likelihood ratio. For the outcomes of spontaneous preterm birth before 34 0/7 and 37 0/7 weeks of gestation, below normal amino-terminal pro-brain natriuretic peptide concentrations had 80.0% sensitivity, 83.0% specificity, 78.0% negative predictive value, 4.70 positive likelihood ratio, and 0.24 negative likelihood ratio and 64.1% sensitivity, 91.7% specificity, 44.0% negative predictive value, 7.70 positive likelihood ratio, and 0.39 negative likelihood ratio, respectively.

CONCLUSION

Among patients in spontaneous preterm labor, the detection of lower-than-normal amino-terminal pro-brain natriuretic peptide concentrations (<0.5 multiples of the median) in amniotic fluid has an excellent predictive capacity to identify those patients at low risk of preterm delivery within 48 hours or 7 days.

Analysis of Factors Contributing to Antenatal Corticosteroid Administration in Patients Presenting with Threatened Preterm Labor

OBJECTIVE

 This study aimed to analyze characteristics of those seen for threatened preterm labor (tPTL) who receive antenatal corticosteroids (ACS) to better understand clinical decision-making.

STUDY DESIGN

 This retrospective cohort study consisted of patients seen in triage at an urban county hospital in 2021 for tPTL during pregnancy. Demographic variables (maternal age, race/ethnicity, and prior preterm delivery) and obstetrical variables (cervical dilation, effacement, membrane rupture, and tocolytic administration) were evaluated against the primary outcome of ACS administration.

RESULTS

 After exclusions, a cohort of 290 pregnant people with 372 unique encounters for tPTL remained. The mean maternal age was 26.7, and 15.6% of patients had a history of prior preterm birth. A total of 107 patients in 111 encounters received ACS, which were associated with lower body mass index (BMI), greater cervical dilation, greater effacement, membrane rupture, and more frequent contractions (all ps < 0.01). The mean presentation was at 33.5 weeks. Only 44% of those receiving ACS delivered within 7 days, compared with 11% of those who did not receive ACS (p < 0.001). Half (50%) of the patients receiving ACS delivered at >37 weeks. Adjusting for significant factors in the univariable analysis and limited to first encounter in triage, BMI (odds ratio: 0.91, 95% confidence interval: 0.87-0.95), cervical dilation ≥ 2 cm (2.49, 1.12-5.35), and cervical effacement ≥ 50% (4.80, 2.25-10.24) were significantly associated with patients receiving ACS.

CONCLUSION

 Greater cervical dilation and effacement and a lower BMI were associated with ACS administration, although most patients receiving ACS still did not deliver within 7 days.

KEY POINTS

· In a cohort of 290 patients with 373 encounters for threatened preterm labor, 37% received ACS.. · We found that only 40% of those who received ACS delivered within 7 days and half went on to deliver at term.. · Cervical dilation ≥2 cm (odds ratio, 95% confidence interval: 2.49, 1.12-5.35) and effacement ≥50% (4.80, 2.25-10.24) were independently associated with receiving ACS..

Preterm Birth: Screening and Prediction

Preterm birth (PTB) affects approximately 10% of births globally each year and is the most significant direct cause of neonatal death and of long-term disability worldwide. Early identification of women at high risk of PTB is important, given the availability of evidence-based, effective screening modalities, which facilitate decision-making on preventative strategies, particularly transvaginal sonographic cervical length (CL) measurement. There is growing evidence that combining CL with quantitative fetal fibronectin (qfFN) and maternal risk factors in the extensively peer-reviewed and validated QUanititative Innovation in Predicting Preterm birth (QUiPP) application can aid both the triage of patients who present as emergencies with symptoms of preterm labor and high-risk asymptomatic women attending PTB surveillance clinics. The QUiPP app risk of delivery thus supports shared decision-making with patients on the need for increased outpatient surveillance, in-patient treatment for preterm labor or simply reassurance for those unlikely to deliver preterm. Effective triage of patients at preterm gestations is an obstetric clinical priority as correctly timed administration of antenatal corticosteroids will maximise their neonatal benefits. This review explores the predictive capacity of existing predictive tests for PTB in both singleton and multiple pregnancies, including the QUiPP app v.2. and discusses promising new research areas, which aim to predict PTB through cervical stiffness and elastography measurements, metabolomics, extracellular vesicles and artificial intelligence.

A dual-binding magnetic immunoassay to predict spontaneous preterm birth

Complications posed by preterm birth (delivery before 37 weeks of pregnancy) are a leading cause of newborn morbidity and mortality. The previous discovery and validation of an algorithm that includes maternal serum protein biomarkers, sex hormone-binding globulin (SHBG), and insulin-like growth factor-binding protein 4 (IBP4), with clinical factors to predict preterm birth represents an opportunity for the development of a widely accessible point-of-care assay to guide clinical management. Toward this end, we developed SHBG and IBP4 quantification assays for maternal serum using giant magnetoresistive (GMR) sensors and a self-normalizing dual-binding magnetic immunoassay. The assays have a picomolar limit of detections (LOD) with a relatively broad dynamic range that covers the physiological level of the analytes as they change throughout gestation. Measurement of serum from pregnant donors using the GMR assays was highly concordant with those obtained using a clinical mass spectrometry (MS)-based assay for the same protein markers. The MS assay requires capitally intense equipment and highly trained operators with a few days turnaround time, whereas the GMR assays can be performed in minutes on small, inexpensive instruments with minimal personnel training and microfluidic automation. The potential for high sensitivity, accuracy, and speed of the GMR assays, along with low equipment and personnel requirements, make them good candidates for developing point-of-care tests. Rapid turnaround risk assessment for preterm birth would enable patient testing and counseling at the same clinic visit, thereby increasing the timeliness of recommended interventions.

Using Fetal Fibronectin Test to Reduce Hospital Admissions with Diagnosis of Preterm Labor: An Economic Evaluation Study

Background: Preterm labor and delivery remain a major problem in obstetrics accounting for perinatal morbidity and mortality. The challenge is to identify those with true preterm labor to avoid unnecessary hospital admissions. The fetal fibronectin (FFN) test is a strong predictor of preterm birth and can help identify women with true preterm labor. However, its cost-effectiveness as a strategy for triaging women with threatened preterm labor is still debatable. Objective: To evaluate the effect of FFN test implementation on hospital resources by reducing the admission rate of threatened preterm labor in a tertiary hospital, Latifa Hospital, UAE. Methods: A retrospective cohort study of singleton pregnancies between 24 and 34 weeks of gestation who attended Latifa Hospital in the period of September 2015-December 2016, complaining of threatened preterm labor after the availability of an FFN test, and a historical cohort study for those who attended with threatened preterm labor before the availability of an FFN test. Data analysis was performed using a Kruskal-Wallis test, Kaplan-Meier, Fischer exact chi-square and cost analysis. The significance was set at p-value < 0.05. Results: In total, 840 women met the inclusion criteria and were enrolled. The relative risk of FFN for delivery at term was 4.35 times higher among the negative-tested compared to preterm delivery (p-value < 0.001). A total of 134 (15.9%) women were unnecessarily admitted (FFN tested negative, delivered at term) which yielded $107,000 in extra costs. After the introduction of an FFN test, a 7% reduction of threatened preterm labor admissions was recorded.

Psychological impact of simple scoring system for predicting early pregnancy outcome in pregnancy of uncertain viability: randomized controlled trial

OBJECTIVE

To investigate whether psychological wellbeing of women with an intrauterine pregnancy of uncertain viability can be modified during the waiting period to final diagnosis, by offering predictive information regarding the likely outcome of the pregnancy (chance of ongoing viability).

METHODS

This was a single-center two-arm randomized controlled trial conducted over 18 months at a teaching hospital in London, UK. Consecutive eligible women attending the early pregnancy assessment unit with an interim ultrasound finding of intrauterine pregnancy of uncertain viability were recruited. All women were offered a follow-up ultrasound scan after 14 days. Participants were randomized to receive a prediction score for ongoing viability at 14 days or routine care (control). Anxiety, depression and worry symptoms were assessed using validated self-report questionnaires (hospital anxiety and depression scale (HADS), Penn state worry questionnaire (PSWQ)) prior to randomization and at two further timepoints during the waiting period preceding final diagnosis. The change in psychological scores over the study period was analyzed. The secondary outcome was the perceived value of the risk prediction tool reported by participants.

RESULTS

A total of 278 women participated in this study. After adjusting for baseline scores, no difference in anxiety, depression or worry scores was demonstrated between control and intervention groups at either timepoint. Subgroup analysis, first of women with high initial anxiety (HADS > 11) or worry (PSWQ ≥ 45), and second of women with a more favorable predicted prognosis (≥ 75% chance of ongoing viability), demonstrated no difference between intervention and control groups. Despite this, 76/110 (69.1% (95% CI, 60.5-78.4%)) women who provided feedback in the intervention group found it to be helpful and 97/110 (88.2% (95% CI, 81.0-93.7%)) reported that they would use the tool again.

CONCLUSION

Current prediction tools may be useful for healthcare professionals to guide management and optimize utilization of early pregnancy resources. However, in this study, implementation of an accurate tool did not result in an objective measurable benefit to patients in terms of reduction in anxiety, depression and worry symptoms experienced during the waiting period to final outcome compared with women who did not receive a prediction score. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

The amniotic fluid proteome predicts imminent preterm delivery in asymptomatic women with a short cervix

Preterm birth, the leading cause of perinatal morbidity and mortality, is associated with increased risk of short- and long-term adverse outcomes. For women identified as at risk for preterm birth attributable to a sonographic short cervix, the determination of imminent delivery is crucial for patient management. The current study aimed to identify amniotic fluid (AF) proteins that could predict imminent delivery in asymptomatic patients with a short cervix. This retrospective cohort study included women enrolled between May 2002 and September 2015 who were diagnosed with a sonographic short cervix (< 25 mm) at 16–32 weeks of gestation. Amniocenteses were performed to exclude intra-amniotic infection; none of the women included had clinical signs of infection or labor at the time of amniocentesis. An aptamer-based multiplex platform was used to profile 1310 AF proteins, and the differential protein abundance between women who delivered within two weeks from amniocentesis, and those who did not, was determined. The analysis included adjustment for quantitative cervical length and control of the false-positive rate at 10%. The area under the receiver operating characteristic curve was calculated to determine whether protein abundance in combination with cervical length improved the prediction of imminent preterm delivery as compared to cervical length alone. Of the 1,310 proteins profiled in AF, 17 were differentially abundant in women destined to deliver within two weeks of amniocentesis independently of the cervical length (adjusted p-value < 0.10). The decreased abundance of SNAP25 and the increased abundance of GPI, PTPN11, OLR1, ENO1, GAPDH, CHI3L1, RETN, CSF3, LCN2, CXCL1, CXCL8, PGLYRP1, LDHB, IL6, MMP8, and PRTN3 were associated with an increased risk of imminent delivery (odds ratio > 1.5 for each). The sensitivity at a 10% false-positive rate for the prediction of imminent delivery by a quantitative cervical length alone was 38%, yet it increased to 79% when combined with the abundance of four AF proteins (CXCL8, SNAP25, PTPN11, and MMP8). Neutrophil-mediated immunity, neutrophil activation, granulocyte activation, myeloid leukocyte activation, and myeloid leukocyte-mediated immunity were biological processes impacted by protein dysregulation in women destined to deliver within two weeks of diagnosis. The combination of AF protein abundance and quantitative cervical length improves prediction of the timing of delivery compared to cervical length alone, among women with a sonographic short cervix.

Increasing the Prediction Power of Preterm Labor using Interleukin 6 and Fetal Fibronectin as Alarming Signals in Symptomatic Patients

Background: Giving birth at preterm is considered as a bothering problem to both healthcare systems and pregnant women around the world, causing alarming levels of mortality. To avoid this issue, certain biological markers can be employed for early detection to predict the occurrence of the PTD (PTD) ahead of time for giving better medical care to the pregnant women who at risk of PTD. Objective: The current study was performed to evaluate the power of using interleukin-6 (IL-6) and fetal fibronectin (fFN) present in the cervicovaginal fluid (CVF) as predictors of the symptomatic PTD patients. Patients & Methods: In this study, 91 pregnant hospital attendees (24-34 weeks; 18-45 years old) with suggested PTD symptoms, such as abdominal pain and uterine contraction and with cervical length of less than 25mm, were participated. To detect IL-6 and fFN, vaginal swabs were collected for performing an ELISA test to later follow up with the patients within 48hrs, seven days, and 14 days from the first day of admission to the hospital.  Results: No significant association between PTD with patients age, parity, BMI, and gestational age, but significant association with previous history of PTD. There was significant association between PTD and increase the level of CVF fFN and IL-6 with best cut-off value for CVF fFN is(>45ng/ml) with (95%CI of 0.763-0.918) and accuracy of 85.2% with a sensitivity of 73.1% and specificity of 95.6% which is of high significant value (P≤0.01).While CVF of IL-6 (>231pg/ml) with (95% CI of 0.630- 0.820), with accuracy of 73.3%,  sensitivity of 50% and specificity of 96.9% which was statistically significant finding (P≤0.01).The predictive value of combined fFN and IL-6  in women at risk  of preterm labor was 84.6% with sensitivity 84.6%,specificity 92.3%, positive predictive value (PPV) 81.5%, negative predictive value (PPV) 93.8% and accuracy of 90.1%. Conclusion:  Each of fFN or IL-6 located in the CVF may provide a strong predictor of PTD; however, this prediction capability may provide an even stronger signal of detecting PTD ahead of time if both biomarkers requested at the same time.

Challenges in Interpreting the Ob/Gyn Literature: Studies of Screening

Screening tests are critical to patient care. Screening tests must meet ten criteria established by the World Health Organization in order to be considered effective. Common types of studies on screening tests include those that establish test characteristics, such as sensitivity, specificity, positive predictive value, and negative predictive value, as well as cost-effective analyses. In this paper, we review the criteria for effective screening tests, and discuss the strengths and pitfalls of common study designs evaluating screening tests.

Change in cervical length after arrested preterm labor and risk of preterm birth

OBJECTIVE

To assess the association between preterm birth and cervical length after arrested preterm labor in high-risk pregnant women.

METHODS

In this post-hoc analysis of a randomized clinical trial, transvaginal cervical length was measured in women whose contractions had ceased 48 h after admission for threatened preterm labor. At admission, women were defined as having a high risk of preterm birth based on a cervical length of < 15 mm or a cervical length of 15-30 mm with a positive fetal fibronectin test. Logistic regression analysis was used to investigate the association of cervical length measured at least 48 h after admission and of the change in cervical length between admission and at least 48 h later, with preterm birth before 34 weeks' gestation and delivery within 7 days after admission.

RESULTS

A total of 164 women were included in the analysis. Women whose cervical length increased between admission for threatened preterm labor and 48 h later (32%; n = 53) were found to have a lower risk of preterm birth before 34 weeks compared with women whose cervical length did not change (adjusted odds ratio (aOR), 0.24 (95% CI, 0.09-0.69)). The risk in women with a decrease in cervical length between the two timepoints was not different from that in women with no change in cervical length (aOR, 1.45 (95% CI, 0.62-3.41)). Moreover, greater absolute cervical length after 48 h was associated with a lower risk of preterm birth before 34 weeks (aOR, 0.90 (95% CI, 0.84-0.96)) and delivery within 7 days after admission (aOR, 0.91 (95% CI, 0.82-1.02)). Sensitivity analysis in women randomized to receive no intervention showed comparable results.

CONCLUSION

Our study suggests that the risk of preterm birth before 34 weeks is lower in women whose cervical length increases between admission for threatened preterm labor and at least 48 h later when contractions had ceased compared with women in whom cervical length does not change or decreases. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Are newborn outcomes different for term babies who were exposed to antenatal corticosteroids?

BACKGROUND

Antenatal corticosteroids improve newborn outcomes for preterm infants. However, predicting which women presenting for threatened preterm labor will have preterm infants is inaccurate, and many women receive antenatal corticosteroids but then go on to deliver at term.

OBJECTIVE

This study aimed to compare the short-term outcomes of infants born at term to women who received betamethasone for threatened preterm labor with infants who were not exposed to betamethasone in utero.

STUDY DESIGN

We performed a retrospective cohort study of infants born at or after 37 weeks' gestational age to mothers diagnosed as having threatened preterm labor during pregnancy. The primary neonatal outcomes of interest included transient tachypnea of the newborn, neonatal intensive care unit admission, and small for gestational age and were evaluated for their association with betamethasone exposure while adjusting for covariates using multiple logistic regression.

RESULTS

Of 5330 women, 1459 women (27.5%) received betamethasone at a mean gestational age of 32.2±3.3 weeks. The mean age of women was 27±5.9 years and the mean gestational age at delivery was 38.9±1.1 weeks. Women receiving betamethasone had higher rates of maternal comorbidities (P<.001 for diabetes mellitus, asthma, and hypertensive disorder) and were more likely to self-identify as White (P=.022). Betamethasone-exposed neonates had increased rates of transient tachypnea of the newborn, neonatal intensive care unit admission, small for gestational age, hyperbilirubinemia, and hypoglycemia (all, P<.05). Controlling for maternal characteristics and gestational age at delivery, betamethasone exposure was not associated with a diagnosis of transient tachypnea of the newborn (adjusted odds ratio, 1.10; 95% confidence interval, 0.80-1.51), although it was associated with more neonatal intensive care unit admissions (adjusted odds ratio, 1.49; 95% confidence interval, 1.19-1.86) and higher odds of the baby being small for gestational age (adjusted odds ratio, 1.78; 95% confidence interval, 1.48-2.14).

CONCLUSION

Compared with women evaluated for preterm labor who did not receive betamethasone, women receiving betamethasone had infants with higher rates of neonatal intensive care unit admission and small for gestational age. Although the benefits of betamethasone to infants born preterm are clear, there may be negative impacts for infants delivered at term.

A prognostic model, including quantitative fetal fibronectin, to predict preterm labour: the QUIDS meta-analysis and prospective cohort study

BACKGROUND

The diagnosis of preterm labour is challenging. False-positive diagnoses are common and result in unnecessary, potentially harmful treatments (e.g. tocolytics, antenatal corticosteroids and magnesium sulphate) and costly hospital admissions. Measurement of fetal fibronectin in vaginal fluid is a biochemical test that can indicate impending preterm birth.

OBJECTIVES

To develop an externally validated prognostic model using quantitative fetal fibronectin concentration, in combination with clinical risk factors, for the prediction of spontaneous preterm birth and to assess its cost-effectiveness.

DESIGN

The study comprised (1) a qualitative study to establish the decisional needs of pregnant women and their caregivers, (2) an individual participant data meta-analysis of existing studies to develop a prognostic model for spontaneous preterm birth within 7 days in women with symptoms of preterm labour based on quantitative fetal fibronectin and clinical risk factors, (3) external validation of the prognostic model in a prospective cohort study across 26 UK centres, (4) a model-based economic evaluation comparing the prognostic model with qualitative fetal fibronectin, and quantitative fetal fibronectin with cervical length measurement, in terms of cost per QALY gained and (5) a qualitative assessment of the acceptability of quantitative fetal fibronectin.

DATA SOURCES/SETTING

The model was developed using data from five European prospective cohort studies of quantitative fetal fibronectin. The UK prospective cohort study was carried out across 26 UK centres.

PARTICIPANTS

Pregnant women at 22⁺⁰-34⁺⁶ weeks' gestation with signs and symptoms of preterm labour.

HEALTH TECHNOLOGY BEING ASSESSED

Quantitative fetal fibronectin.

MAIN OUTCOME MEASURES

Spontaneous preterm birth within 7 days.

RESULTS

The individual participant data meta-analysis included 1783 women and 139 events of spontaneous preterm birth within 7 days (event rate 7.8%). The prognostic model that was developed included quantitative fetal fibronectin, smoking, ethnicity, nulliparity and multiple pregnancy. The model was externally validated in a cohort of 2837 women, with 83 events of spontaneous preterm birth within 7 days (event rate 2.93%), an area under the curve of 0.89 (95% confidence interval 0.84 to 0.93), a calibration slope of 1.22 and a Nagelkerke R ² of 0.34. The economic analysis found that the prognostic model was cost-effective compared with using qualitative fetal fibronectin at a threshold for hospital admission and treatment of ≥ 2% risk of preterm birth within 7 days.

LIMITATIONS

The outcome proportion (spontaneous preterm birth within 7 days of test) was 2.9% in the validation study. This is in line with other studies, but having slightly fewer than 100 events is a limitation in model validation.

CONCLUSIONS

A prognostic model that included quantitative fetal fibronectin and clinical risk factors showed excellent performance in the prediction of spontaneous preterm birth within 7 days of test, was cost-effective and can be used to inform a decision support tool to help guide management decisions for women with threatened preterm labour.

FUTURE WORK

The prognostic model will be embedded in electronic maternity records and a mobile telephone application, enabling ongoing data collection for further refinement and validation of the model.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42015027590 and Current Controlled Trials ISRCTN41598423.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 52. See the NIHR Journals Library website for further project information.

Development of Polydiacetylene-Based Testosterone Detection as a Model Sensing Platform for Water-Insoluble Hormone Analytes

We have developed a polydiacetylene (PDA)-based sensing platform to detect testosterone (T) as a potential biomarker of preterm birth. The insolubility of the steroid hormone in water, where PDA assemblies are dispersed, poses a major issue, since they can hardly interact with each other. To overcome this challenge, acetonitrile was used as a suitable solvent. In addition, to minimize false signals of PDA assemblies caused by the solvent, a mixture of acetonitrile and distilled water was selected. To prove a concept of PDA-based sensing platform for targeting T hormone, we conjugated anti-T antibodies to surface of PDA assemblies to induce selective binding between T and anti-T antibodies. The fluorescence sensory signaling of the PDA-anti-T antibody conjugate was selectively generated for T, over 3.4 times higher sensitivity of the signaling compared to that from other sex steroid hormones studied (β-estradiol and progesterone).

Development and validation of a risk prediction model of preterm birth for women with preterm labour symptoms (the QUIDS study): A prospective cohort study and individual participant data meta-analysis

BACKGROUND

Timely interventions in women presenting with preterm labour can substantially improve health outcomes for preterm babies. However, establishing such a diagnosis is very challenging, as signs and symptoms of preterm labour are common and can be nonspecific. We aimed to develop and externally validate a risk prediction model using concentration of vaginal fluid fetal fibronectin (quantitative fFN), in combination with clinical risk factors, for the prediction of spontaneous preterm birth and assessed its cost-effectiveness.

METHODS AND FINDINGS

Pregnant women included in the analyses were 22+0 to 34+6 weeks gestation with signs and symptoms of preterm labour. The primary outcome was spontaneous preterm birth within 7 days of quantitative fFN test. The risk prediction model was developed and internally validated in an individual participant data (IPD) meta-analysis of 5 European prospective cohort studies (2009 to 2016; 1,783 women; mean age 29.7 years; median BMI 24.8 kg/m2; 67.6% White; 11.7% smokers; 51.8% nulliparous; 10.4% with multiple pregnancy; 139 [7.8%] with spontaneous preterm birth within 7 days). The model was then externally validated in a prospective cohort study in 26 United Kingdom centres (2016 to 2018; 2,924 women; mean age 28.2 years; median BMI 25.4 kg/m2; 88.2% White; 21% smokers; 35.2% nulliparous; 3.5% with multiple pregnancy; 85 [2.9%] with spontaneous preterm birth within 7 days). The developed risk prediction model for spontaneous preterm birth within 7 days included quantitative fFN, current smoking, not White ethnicity, nulliparity, and multiple pregnancy. After internal validation, the optimism adjusted area under the curve was 0.89 (95% CI 0.86 to 0.92), and the optimism adjusted Nagelkerke R2 was 35% (95% CI 33% to 37%). On external validation in the prospective UK cohort population, the area under the curve was 0.89 (95% CI 0.84 to 0.94), and Nagelkerke R2 of 36% (95% CI: 34% to 38%). Recalibration of the model's intercept was required to ensure overall calibration-in-the-large. A calibration curve suggested close agreement between predicted and observed risks in the range of predictions 0% to 10%, but some miscalibration (underprediction) at higher risks (slope 1.24 (95% CI 1.23 to 1.26)). Despite any miscalibration, the net benefit of the model was higher than "treat all" or "treat none" strategies for thresholds up to about 15% risk. The economic analysis found the prognostic model was cost effective, compared to using qualitative fFN, at a threshold for hospital admission and treatment of ≥2% risk of preterm birth within 7 days. Study limitations include the limited number of participants who are not White and levels of missing data for certain variables in the development dataset.

CONCLUSIONS

In this study, we found that a risk prediction model including vaginal fFN concentration and clinical risk factors showed promising performance in the prediction of spontaneous preterm birth within 7 days of test and has potential to inform management decisions for women with threatened preterm labour. Further evaluation of the risk prediction model in clinical practice is required to determine whether the risk prediction model improves clinical outcomes if used in practice.

TRIAL REGISTRATION

The study was approved by the West of Scotland Research Ethics Committee (16/WS/0068). The study was registered with ISRCTN Registry (ISRCTN 41598423) and NIHR Portfolio (CPMS: 31277).

Evaluating the use of the QUiPP app and its impact on the management of threatened preterm labour: A cluster randomised trial

BACKGROUND

Preterm delivery (before 37 weeks of gestation) is the single most important contributor to neonatal death and morbidity, with lifelong repercussions. However, the majority of women who present with preterm labour (PTL) symptoms do not deliver imminently. Accurate prediction of PTL is needed in order ensure correct management of those most at risk of preterm birth (PTB) and to prevent the maternal and fetal risks incurred by unnecessary interventions given to the majority. The QUantitative Innovation in Predicting Preterm birth (QUIPP) app aims to support clinical decision-making about women in threatened preterm labour (TPTL) by combining quantitative fetal fibronectin (qfFN) values, cervical length (CL), and significant PTB risk factors to create an individualised percentage risk of delivery.

METHODS AND FINDINGS

EQUIPTT was a multi-centre cluster randomised controlled trial (RCT) involving 13 maternity units in South and Eastern England (United Kingdom) between March 2018 and February 2019. Pregnant women (n = 1,872) between 23+0 and 34+6 weeks' gestation with symptoms of PTL in the analysis period were assigned to either the intervention (762) or control (1,111). The mean age of the study population was 30.2 (+/- SD 5.93). A total of 56.0% were white, 19.6% were black, 14.2% were Asian, and 10.2% were of other ethnicities. The intervention was the use of the QUiPP app with admission, antenatal corticosteroids (ACSs), and transfer advised for women with a QUiPP risk of delivery >5% within 7 days. Control sites continued with their conventional management of TPTL. Unnecessary management for TPTL was a composite primary outcome defined by the sum of unnecessary admission decisions (admitted and delivery interval >7 days or not admitted and delivery interval ≤7 days) and the number of unnecessary in utero transfer (IUT) decisions/actions (IUT that occurred or were attempted >7 days prior to delivery) and ex utero transfers (EUTs) that should have been in utero (attempted and not attempted). Unnecessary management of TPTL was 11.3% (84/741) at the intervention sites versus 11.5% (126/1094) at control sites (odds ratio [OR] 0.97, 95% confidence interval [CI] 0.66-1.42, p = 0.883). Control sites frequently used qfFN and did not follow UK national guidance, which recommends routine treatment below 30 weeks without testing. Unnecessary management largely consisted of unnecessary admissions which were similar at intervention and control sites (10.7% versus 10.8% of all visits). In terms of adverse outcomes for women in TPTL <36 weeks, 4 women from the intervention sites and 12 from the control sites did not receive recommended management. If the QUiPP percentage risk was used as per protocol, unnecessary management would have been 7.4% (43/578) versus 9.9% (134/1,351) (OR 0.72, 95% CI 0.45-1.16). Our external validation of the QUiPP app confirmed that it was highly predictive of delivery in 7 days; receiver operating curve area was 0.90 (95% CI 0.85-0.95) for symptomatic women. Study limitations included a lack of compliance with national guidance at the control sites and difficulties in implementation of the QUiPP app.

CONCLUSIONS

This cluster randomised trial did not demonstrate that the use of the QUiPP app reduced unnecessary management of TPTL compared to current management but would safely improve the management recommended by the National Institute for Health and Care Excellence (NICE). Interpretation of qfFN, with or without the QUiPP app, is a safe and accurate method for identifying women most likely to benefit from PTL interventions.

TRIAL REGISTRATION

ISRCTN Registry ISRCTN17846337.

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.

AACC Guidance Document on Laboratory Testing for the Assessment of Preterm Delivery

Identifying women with preterm labor who will go on to deliver prematurely is crucial to improving outcomes for mother and baby and for saving healthcare resources. Even among those with symptoms, the number of women who deliver preterm is low, and thus the low positive predictive value (PPV) and high negative predictive value (NPV) associated with available biomarkers does not substantially reduce the uncertainty of the clinical diagnosis. While there is some promise in the use of fetal fibronectin (fFN), interleukin 6 (IL-6), or placental alpha microglobulin 1 (PAMG-1) for predicting preterm birth (PTB), their use is unlikely to provide considerable clinical value in populations with a low prevalence. To provide real clinical benefit, a biomarker must demonstrate a high PPV to allow identification of the minority of symptomatic women who will deliver prematurely. As none of the currently available biomarkers exhibit this performance characteristic, we do not recommend their routine clinical use in populations with a pre-test probability of PTB of <5%. Limiting biomarker testing to only high-risk women identified on the basis of cervical length or other characteristics will increase the pre-testprobability in the tested population, thereby improving PPV. PAMG-1 is associated with a higher PPV than fFN and may show clinical utility in populations with a higher pre-test probability, but further work is required to conclusively demonstrate improved outcomes in this patient group.

Development and rapid rollout of The QUiPP App Toolkit for women who arrive in threatened preterm labour

BACKGROUND

Often the first opportunity for clinicians to assess risk of preterm birth is when women present with threatened preterm labour symptoms (such as period-like pain, tightening's or back ache). However, threatened preterm labour symptoms are not a strong predictor of imminent birth. Clinicians are then faced with a complex clinical dilemma, the need to ameliorate the consequences of preterm birth requires consideration with the side-effects and costs. The QUiPP app is a validated app which can aid clinicians when they triage a women who is in threatened preterm labour.

AIM

Our aim was to produce a toolkit to promote a best practice pathway for women who arrive in threatened preterm labour.

METHODS

We worked with two hospitals in South London. This included the aid of a toolkit midwife at each hospital. We also undertook stakeholder focus groups and worked with two Maternity Voice Partnership groups to ensure a diverse range of voices was heard in the toolkit development. While we aimed to produce the toolkit in September 2020, we rapidly rolled out and produced the first version of the toolkit in April 2020 due to COVID-19. As the QUiPP app can reduce admissions and hospital transfers, there was a need to enable all hospitals in England to have access to the toolkit as soon as possible.

RESULTS

While the rapid rollout of The QUiPP App Toolkit due to COVID-19 was not planned, it has demonstrated that toolkits to improve clinical practice can be produced promptly. Through actively welcoming continued feedback meant the initial version of the toolkit could be continually and iteratively refined. The toolkit has been recommended nationally, with National Health Service England recommending the app and toolkit in their COVID-19 update to the Saving Babies Lives Care Bundle and in the British Association of Perinatal Medicine Antenatal Optimisation Toolkit.

Identifying the potential protein biomarkers of preterm birth in amniotic fluid

OBJECTIVE

Preterm birth severely threatens neonatal health and life. Although the detailed mechanism of preterm birth is not well understood, accurately predicting preterm birth can help people make preparations in advance, greatly reducing the subsequent health risk of neonates. Therefore, in this study, we aimed to identify potential protein biomarkers of preterm birth in amniotic fluid (AF).

MATERIALS AND METHODS

We first enrolled pregnant subjects and collected their AF samples when they underwent amniocentesis at the second trimester of gestation. After delivery, the collected AF samples were classified into a full-term birth (sample size n = 21) set or preterm birth (n = 36) set, followed by 2-D DIGE and MS/MS assays.

RESULTS

By doing so, we identified seven potential protein biomarkers of preterm birth, three of which were further validated in all samples with ELISA, including Apolipoprotein A-IV (Apoa4), Lumican (Lum) and Kininogen-1 (Kng1). As a result, all three potential biomarkers were significantly differently expressed between preterm and full-term birth AF samples. Furthermore, without prior classification, we found that these three biomarkers were positively correlated with gestation age (correlation coefficient ranging from 0.25 to 0.38) and were able to predict the occurrence of preterm birth.

CONCLUSION

In this study, by examining amniotic fluid, we identified three biomarker proteins that may facilitate the identification of preterm birth. There three proteins were never reported to be related to preterm birth. Their pathogenesis roles in preterm birth deserve further investigations by using in vitro cell model or in vivo animal model assays.

Uterocervical Angle and Cervical Length as a Tool to Predict Preterm Birth in Threatened Preterm Labor

Objective

To evaluate the diagnostic performance of uterocervical angle (UCA) and UCA with cervical length (CL) in predicting preterm delivery in threatened preterm labor.

Methods

A multicenter prospective observational cohort study was conducted in 160 pregnant women having threatened preterm labor at Srinagarind and Udonthani Hospitals in Thailand between March 2019 and June 2020. Researchers measured UCA and CL by transvaginal ultrasonography. Medical records were reviewed for patient characteristics, and patients were followed up until the date of delivery to assess for the outcome of preterm birth. The cut-off point of UCA was determined from receiver operating characteristic curve analysis. The sensitivity, specificity, likelihood ratio, positive and negative predictive values (PPV and NPV) of UCA and of UCA with CL for predicting preterm birth were determined.

Results

The incidence of preterm birth in women having threatened preterm labor was 27%. The sensitivity, specificity, PPV and NPV of UCA ≥110.97 degrees for predicting preterm birth were 65.1%, 43.6%, 29.8% and 77.3%, respectively. The sensitivity, specificity, PPV and NPV of UCA ≥110.97 degrees with CL <3.4 centimeters for predicting preterm birth were 48.8%, 68.4%, 36.2% and 78.4%. The specificity and NPV of UCA with CL were higher than for UCA alone.

Conclusion

With adequate sensitivity and high NPV, UCA by TVS can be supplemented with CL measurement in threatened preterm labor management to increase the diagnostic performance for predicting preterm birth.

Maternal metabolic profiling to assess fetal gestational age and predict preterm delivery: a two-centre retrospective cohort study in the US

OBJECTIVES

The aim of this study was to develop a single blood test that could determine gestational age and estimate the risk of preterm birth by measuring serum metabolites. We hypothesised that serial metabolic modelling of serum analytes throughout pregnancy could be used to describe fetal gestational age and project preterm birth with a high degree of precision.

STUDY DESIGN

A retrospective cohort study.

SETTING

Two medical centres from the USA.

PARTICIPANTS

Thirty-six patients (20 full-term, 16 preterm) enrolled at Stanford University were used to develop gestational age and preterm birth risk algorithms, 22 patients (9 full-term, 13 preterm) enrolled at the University of Alabama were used to validate the algorithms.

OUTCOME MEASURES

Maternal blood was collected serially throughout pregnancy. Metabolic datasets were generated using mass spectrometry.

RESULTS

A model to determine gestational age was developed (R²=0.98) and validated (R²=0.81). 66.7% of the estimates fell within ±1 week of ultrasound results during model validation. Significant disruptions from full-term pregnancy metabolic patterns were observed in preterm pregnancies (R²=-0.68). A separate algorithm to predict preterm birth was developed using a set of 10 metabolic pathways that resulted in an area under the curve of 0.96 and 0.92, a sensitivity of 0.88 and 0.86, and a specificity of 0.96 and 0.92 during development and validation testing, respectively.

CONCLUSIONS

In this study, metabolic profiling was used to develop and test a model for determining gestational age during full-term pregnancy progression, and to determine risk of preterm birth. With additional patient validation studies, these algorithms may be used to identify at-risk pregnancies prompting alterations in clinical care, and to gain biological insights into the pathophysiology of preterm birth. Metabolic pathway-based pregnancy modelling is a novel modality for investigation and clinical application development.

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.

The utility of fetal fibronectin in asymptomatic singleton and twin pregnancies with a cervical length ≤ 10 mm

Objective: To examine the utility of fetal fibronectin (fFN) for predicting spontaneous preterm birth (PTB) in asymptomatic women with a cervical length (CL) ≤10 mm compared to those with a CL 11-25 mm.Methods: Data was collected on all women with nonanomalous singleton and twin gestations who underwent transvaginal CL at a single institution between 2009 and 2012. Women with an incidental short cervix (CL ≤ 25 mm) between 22 and 32 weeks who had an fFN result within 7 days thereafter were included. Indicated preterm deliveries at <14 days of fFN, women who underwent cerclage placement, and terminations of pregnancy were excluded. The primary outcome was spontaneous PTB within 7 and 14 days of the fFN. Sensitivity, specificity, and positive (PPV) and negative predictive value (NPV) of fFN for a CL ≤ 10 mm was calculated for singletons and twins and compared to those with a CL 11-25 mm.Results: Of the 213 women included, 117 (54.9%) were singletons and 96 (45%) were twins. Baseline characteristics were similar between those with a CL ≤ 10 mm and with a CL 11-25 mm in both singletons and twins. The NPV of fFN for delivery within 7 days in singletons and twins with a CL ≤ 10 mm was 100%, similar to those with a CL 11-25 mm (93-100%). The NPV of fFN for delivery within 14 days in singletons and twins with a CL ≤ 10 mm remained high (87.5-100%) when compared to those with a CL 11-25 mm (93-100%). The PPV of fFN for delivery within 7 and 14 days in both singletons and twins with a CL ≤ 10 mm was low (10-25%) and similar to those with a CL 11-25 mm (7.1-24.4%).Conclusions: The NPV of fFN in asymptomatic singleton and twin pregnancies with a CL ≤ 10 mm is high and comparable to the NPV of fFN in women with a longer CL. Routine fFN collection in this select population should be considered as it may avoid unnecessary and costly admissions, as well as assist with timing of antenatal corticosteroids.

All the right moves: why in utero transfer is both important for the baby and difficult to achieve and new strategies for change

The best way to ensure that preterm infants benefit from relevant neonatal expertise as soon as they are born is to transfer the mother and baby to an appropriately specialised neonatal facility before birth (“ in utero”). This review explores the evidence surrounding the importance of being born in the right unit, the advantages of in utero transfers compared to ex utero transfers, and how to accurately assess which women are at most risk of delivering early and the challenges of in utero transfers.

Accurate identification of the women most at risk of preterm birth is key to prioritising who to transfer antenatally, but the administrative burden and pathway variation of in utero transfer in the UK are likely to compromise optimal clinical care. Women reported the impact that in utero transfers have on them, including the emotional and financial burdens of being transferred and the anxiety surrounding domestic and logistical concerns related to being away from home. The final section of the review explores new approaches to reforming the in utero transfer process, including learning from outside the UK and changing policy and guidelines. Examples of collaborative regional guidance include the recent Pan-London guidance on in utero transfers. Reforming the transfer process can also be aided through technology, such as utilising the CotFinder app.

In utero transfer is an unavoidable aspect of maternity and neonatal care, and the burden will increase if preterm birth rates continue to rise in association with increased rates of multiple pregnancy, advancing maternal age, assisted reproductive technologies, and obstetric interventions. As funding and capacity pressures on health services increase because of the COVID-19 pandemic, better prioritisation and sustained multi-disciplinary commitment are essential to maximise better outcomes for babies born too soon.

Compliance with Fetal Fibronectin Testing at a Canadian Tertiary Care Perinatal Centre

OBJECTIVE

The purpose of this study was to assess compliance with fetal fibronectin (fFN) testing recommendations at a single tertiary care perinatal centre. The secondary objective was to identify factors associated with compliance with these recommendations.

METHODS

A retrospective cohort study was conducted from January 1, 2016 to December 31, 2016 of all patients who presented to the IWK Health Centre with suspected preterm labour. Inclusion criteria included symptoms of preterm labour prior to 37⁰ weeks gestation, singleton or multiple pregnancy, and established fetal wellbeing. Exclusion criteria included severe fetal anomaly, contraindications to tocolysis, transfer from community hospital, or inadequate documentation. Provider compliance was evaluated to determine: 1) whether the test was performed for appropriate indications according to provincial fFN guidelines; 2) whether fFN results were appropriately being used to inform patient care. Logistic regression was used to determine factors associated with compliance.

RESULTS

A total of 528 patients presented with symptoms of preterm labour. The overall compliance with testing recommendations was 76.1%. Compliance for patients who met criteria for fFN testing was 73%, and compliance for those not meeting criteria was 76.4%. Of patients with a negative fFN result, 85.3% were appropriately discharged home without intervention. Gestational age, time of day, and non-obstetrician provider type were found to be associated with compliance.

CONCLUSION

Despite regional and national guidelines, this study demonstrates a compliance rate of 76% in our centre, indicating a gap in provider knowledge regarding proper use and interpretation of fFN. Non-obstetrician provider type was associated with decreased compliance.

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.

Comparison of Fetal Fibronectin and Phosphorylated Insulin-Like Growth Factor Binding Protein-1 Testing to Predict Preterm Delivery in Symptomatic Women: A 10-Year Retrospective Study

OBJECTIVE

To assess the diagnostic accuracy and cost-effectiveness of fetal fibronectin (fFN) and cervical phosphorylated insulin-like growth factor binding protein-1 (phIGFBP-1) tests, individually and in combination, to predict preterm delivery within 48 hours, 7 days and 14 days in symptomatic women.

METHOD

We selected women in Victoria, British Columbia, who presented between January 2008 and December 2017 at <34 weeks gestation at intermediate risk for labour (intact membrane, cervical dilatation <3 cm, and >6 contractions per hour). We calculated sensitivity, specificity, and positive and negative predictive values (PPV, NPV) for independent and concurrent testing and conducted a cost-effectiveness analysis to ensure appropriate test utilization.

RESULTS

We identified 2911 cases. Both fFN and phIGFBP-1 tests showed high and comparable NPV in predicting risk of delivery within 48 hours, 7 days and 14 days (fFN: 99.3%, 98.5% and 97.3%; phIGFBP-1: 98.8%, 97.9% and 96.1%). In 1976 cases, samples for fFN and phIGFBP-1 tests were collected and analyzed concurrently. Concurrent analysis increased specificity (90.8%, 91.4%, and 91.8%) and PPV (11.8%, 19.8% and 24.2%). Independently, both tests had comparable sensitivity, while the fFN test had higher specificity. Concurrent testing offered the highest PPV. The net gain in PPV comes with a clinically insignificant net loss (<1%) in NPV when compared with either of the tests individually.

CONCLUSION

Clinical usefulness of PPV for either test is limited. Routine concurrent testing comes with additional costs, and fFN has additional collection requirements. Point-of-care phIGFBP-1 testing has proven to be cheaper, simpler, and equally effective. Ordering physicians should be provided with education on how to interpret test results and should have protocols to guide clinical decision making.

Development and validation of predictive models for QUiPP App v.2: tool for predicting preterm birth in women with symptoms of threatened preterm labor

OBJECTIVE

To develop enhanced prediction models to update the QUiPP App prototype, a tool providing individualized risk of spontaneous preterm birth (sPTB), for use in women with symptoms of threatened preterm labor (TPTL), incorporating risk factors, transvaginal ultrasound assessment of cervical length (CL) and cervicovaginal fluid quantitative fetal fibronectin (qfFN) test results.

METHODS

Participants were pregnant women between 23 + 0 and 34 + 6 weeks' gestation with symptoms of TPTL, recruited as part of four prospective cohort studies carried out at 16 UK hospitals between October 2010 and October 2017. The training set comprised all women whose outcomes were known in May 2017 (n = 1032). The validation set comprised women whose outcomes were gathered between June 2017 and March 2018 (n = 506). Parametric survival models were developed for three combinations of predictors: risk factors plus qfFN test results alone, risk factors plus CL alone, and risk factors plus both qfFN and CL. The best models were selected using the Akaike and Bayesian information criteria. The estimated probability of sPTB < 30, < 34 or < 37 weeks' gestation and within 1 or 2 weeks of testing was calculated and receiver-operating-characteristics (ROC) curves were created to demonstrate the diagnostic ability of the prediction models.

RESULTS

Predictive statistics were similar between the training and the validation sets at most outcome time points and for each combination of predictors. Areas under the ROC curves (AUC) demonstrated that all three algorithms had good accuracy for the prediction of sPTB at < 30, < 34 and < 37 weeks' gestation and within 1 and 2 weeks' post-testing in the validation set, particularly the model combining risk factors plus qfFN alone (AUC: 0.96 at < 30 weeks; 0.85 at < 34 weeks; 0.77 at < 37 weeks; 0.91 at < 1 week from testing; and 0.92 at < 2 weeks from testing).

CONCLUSIONS

Validation of the new prediction models suggests that the QUiPP App v.2 can reliably calculate risk of sPTB in women with TPTL. Use of the QUiPP App in practice could lead to better targeting of intervention, while providing reassurance and avoiding unnecessary intervention in women at low risk. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

The Biomarkers for Preterm Birth Study-A prospective observational study comparing the impact of vaginal biomarkers on clinical practice when used in women with symptoms of preterm labor

INTRODUCTION

This study aims to compare the use of qualitative fetal fibronectin, quantitative fetal fibronectin, and placental α-microglobulin-1 in women with symptoms of preterm labor, to evaluate which vaginal biomarker performs the best in clinical practice.

MATERIAL AND METHODS

This prospective observational study included women who presented with symptoms of preterm labor at 24⁺⁰ to 34⁺⁰  weeks of gestation at a large tertiary maternity hospital in Auckland, New Zealand. Women were managed according to hospital guidelines using qualitative fetal fibronectin. Quantitative fetal fibronectin and placental α-microglobulin-1 tests were also taken, with clinicians blinded to the results. Management and delivery outcomes were collected from clinical records. The primary outcome was the rate of antenatal hospital admission. Analysis was performed according to predefined management protocols for each of the tests.

RESULTS

A total of 128 women had all three biomarkers tests taken. Spontaneous preterm birth rates were 7/128 (5.5%) ≤34⁺⁰  weeks and 20/128 (15.6%) <37⁺⁰  weeks of gestation; 5/128 (3.9%) delivered within 7 days of testing. Positive results were recorded in 28 qualitative fetal fibronectin tests, 25 quantitative fetal fibronectin tests with 11 ≥200 ng/mL, and 16 placental α-microglobulin-1 tests. The use of quantitative fetal fibronectin or placental α-microglobulin-1 would have lowered antenatal admission rates: 27/128 (21.1%) for qualitative fetal fibronectin, 11/128 (8.6%) for quantitative fetal fibronectin (admission threshold ≥200 ng/mL), and 15/128 (11.7%) for placental α-microglobulin-1. No additional women with quantitative fetal fibronectin <200 ng/mL delivered within 7 days or missed corticosteroids compared with standard care (qualitative fetal fibronectin); however, an additional 3 cases had a false-negative placental α-microglobulin-1 and clinical care may have been compromised (no antenatal corticosteroids or admission).

CONCLUSIONS

The use of quantitative fetal fibronectin (admission threshold ≥200 ng/mL) has the potential to reduce the rate of antenatal admissions for women with symptoms of preterm labor without compromising use of antenatal interventions that improve outcomes for babies born preterm.

The role of the obstetrician in the prevention of retinopathy of prematurity

This review underlines the important role that obstetricians play in the prevention of retinopathy of prematurity. Efforts predominately focus on predicting which pregnant women are at highest risk of preterm birth, instigating treatments to prevent pre-eclampsia, fetal growth restriction and maternal infection which could lead to iatrogenic or spontaneous preterm birth, and optimizing care when preterm birth is inevitable. More broadly, optimizing maternal health pre-conception through stopping smoking, improving diet, reducing obesity with its associated gestational diabetes, and treating hypertension may reduce preterm birth and other pregnancy complications. This is a message that all healthcare professionals including obstetricians, neonatologists and GPs, nursing and midwifery staff need to communicate all women and men who are contemplating having a baby.

Mouse models of preterm birth: suggested assessment and reporting guidelines

Preterm birth affects approximately 1 out of every 10 births in the United States, leading to high rates of mortality and long-term negative health consequences. To investigate the mechanisms leading to preterm birth so as to develop prevention strategies, researchers have developed numerous mouse models of preterm birth. However, the lack of standard definitions for preterm birth in mice limits our field's ability to compare models and make inferences about preterm birth in humans. In this review, we discuss numerous mouse preterm birth models, propose guidelines for experiments and reporting, and suggest markers that can be used to assess whether pups are premature or mature. We argue that adoption of these recommendations will enhance the utility of mice as models for preterm birth.

Predictive value of the quantitative fetal fibronectin levels for the management of women presenting with threatened preterm labour - A revised cut off level: A retrospective cohort study

Objective

To evaluate a new a cut off level of fetal fibronectin as a predictor of birth in women with threatened preterm labour.

Design

A retrospective cohort study performed at Ipswich hospital, Ipswich, Queensland, Australia, in women with threatened preterm labour with intact membranes between 23 weeks to 34 + 6 week gestation.

Study design

A quantitative fetal fibronectin (fFN) was performed. Maternal demographics and birth outcome data were extracted from the routinely collected perinatal data held by the hospital. The odds of preterm birth were estimated for each cut off value of fFN (10, 50 and 200 ng ml⁻¹) using logistic regression and accounting for multiple presentations by the same woman.

Results

Among the 447 presentations and 376 pregnancies, rates of preterm birth <34 weeks were 2.9%, 9.2%, 3.3%, 19.6%, 4.2% and 35.3% for each category of values respectively (fFN <10, ≥10, <50, ≥50, <200 and ≥200 ng ml⁻¹). Birth rates within 7 d of testing were 1.1%, 7.5%, 1.8%, 16.1%, 2.1% and 41.2% respectively. Comparing fFN level of <10 to a level of 10-199 ng ml⁻¹ there was no significant increase in odds of preterm birth < 34 weeks or birth within the next 7 d (OR 2.28, 95% CI 0.84-6.17 and OR 3.61, 95% CI 0.89-14.7 respectively.

Conclusion

In women presenting with TPL, those with levels of <200 ng ml⁻¹ have a low risk of birthing within 7 d or before 34 weeks gestation. This allows a personalised decision making and probable discharge home without need for steroid loading.

A high concentration of fetal fibronectin in cervical secretions increases the risk of intra-amniotic infection and inflammation in patients with preterm labor and intact membranes

Objective To determine whether the risk of intra-amniotic infection/inflammation and spontaneous preterm delivery (SPTD) varies as a function of the concentration of cervical fetal fibronectin (fFN) in patients with preterm labor and intact membranes. Methods This prospective study included 180 patients with preterm labor and intact membranes who had a sample collected for quantitative fFN measurement and underwent amniocentesis. Amniotic fluid was cultured for aerobic and anaerobic bacteria and genital mycoplasmas. Intra-amniotic inflammation was defined as an amniotic fluid matrix metalloproteinase-8 concentration >23 ng/mL. Results (1) The prevalence of intra-amniotic infection/inflammation and SPTD within 7 days was 32.2% (58/180) and 33.9% (61/178), respectively; (2) The higher the fFN concentration, the greater the risk of intra-amniotic infection/inflammation and SPTD within 7 days (P<0.001, respectively); (3) An fFN concentration 150 ng/mL had a better diagnostic performance than an fFN 50 ng/mL in the identification of intra-amniotic infection/inflammation and SPTD within 7 days; (4) Among the patients with an fFN <50 ng/mL, intra-amniotic infection/inflammation was identified in 7.6% (6/79) of patients and 66.7% (4/6) delivered within 7 days. Conclusion The higher the concentration of fFN, the greater the risk of intra-amniotic infection/inflammation and SPTD in patients with preterm labor and intact membranes.

Utility of cervical length and quantitative fetal fibronectin for predicting spontaneous preterm delivery among symptomatic nulliparous women

OBJECTIVE

To validate the utility of fetal fibronectin (fFN) and cervical length (CL) in predicting preterm delivery among symptomatic nulliparous women.

METHODS

A retrospective cohort study of nulliparous women who presented with uterine contractions, abdominal pain, or cervical change at 21-34 gestational weeks at Fukushima Medical University Hospital, Japan, between 2008 and 2017. fFN (categorized as <50 ng/dL, 50-199 ng/dL, >200 ng/dL) and CL (≥15 mm or <15 mm) were evaluated simultaneously. Adjusted odds ratios (aORs) and confidence intervals (CIs) for preterm delivery before 37 or 34 weeks, and delivery within 28 or 14 days were calculated (references: fFN, <50 ng/dL; CL, ≥15 mm).

RESULT

Among 285 women who met the study criteria, CL less than 15 mm was a risk factor for preterm delivery before 37 (aOR, 4.1; 95% CI, 1.1-6.7) and 34 (aOR, 6.8; 95% CI, 2.3-20.2) weeks. fFN of 200 ng/dL or higher was a risk factor for delivery within 28 (aOR, 19.8; 95% CI, 4.3-90.2) and 14 (aOR, 10.8; 95% CI, 1.7-67.6) days.

CONCLUSION

Among symptomatic nulliparous women, short CL was found to be a risk factor for preterm delivery and higher fFN levels were related to short gestational latency.

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.

Fetal fibronectin test for threatened preterm delivery 48h after admission: Cost-effectiveness study

OBJECTIVE

The aim of this work was to assess the cost-effectiveness of the fetal fibronectin (fFN) test at 48 h after admission for threatened preterm delivery to promote early discharge.

STUDY DESIGN

Before-and-after study to calculate the incremental cost-effectiveness ratio (ICER). Patients were enrolled 48 h after admission in a tertiary care centre for threatened preterm delivery between 24⁺⁰ and 34⁺⁶ weeks. fFN testing was performed. During the first period, physician was blinded to fFN test and discharge occurred after apparent reduced symptomatology at physician's discretion. During the second period, fFN test was revealed to physician and discharge was immediately proposed to negative test patients. The costs considered in this analysis were the direct medical costs from the hospital perspective: costs of hospitalisation, treatment, and imaging procedures. The efficacy criterion selected was the number of deliveries at 7 and at 14 days after admission for threatened preterm delivery.

RESULTS

The study included 178 pregnant patient, 99 during the first period (July 2008-October 2009) and 79 during the second (March 2010-February 2012). The lengths of hospital stays were shorter during the second period, with more than 50% of women discharged home between 48 and 72 h (p < 0.0001) resulting in a cost-saving of 76 051 euros. The number of deliveries at 7 and at 14 days was similar between the two periods.

CONCLUSION

The fFN test at 48 h after admission supported early discharge and was safe and cost-effective.

[Preterm Birth Screening: What Does Really Make Sense?]

Preterm Birth Screening: What Does Really Make Sense? Abstract. Spontaneous preterm birth is a syndrome triggered by multiple mechanisms. In view of the pathophysiological heterogeneity of preterm birth, a single biomarker cannot show the required high negative and positive predictive values. From a clinical point of view, anamnesis, sonographic measurement of cervical length, and placental alpha-microglobulin-1 (PAMG-1) testing from cervico-vaginal secretion are established. Further prospective, large-scale longitudinal studies must validate the combined use of new biomarkers.

Prediction of spontaneous preterm delivery in women presenting with premature labor: a comparison of placenta alpha microglobulin-1, phosphorylated insulin-like growth factor binding protein-1, and cervical length

BACKGROUND

Placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 have been studied in patients at risk for preterm birth with signs and symptoms of preterm labor. However, a direct comparison between these 2 biomarkers, alone or in combination with cervical length measurement with an adequate sample size, has been lacking to date.

OBJECTIVE

The purpose of this study was to compare the placental alpha microglobulin-1 test and the phosphorylated insulin-like growth factor-binding protein-1 test alone and in combination with cervical length measurement for the prediction of imminent spontaneous preterm birth of testing in pregnant women with symptoms of preterm labor in a tertiary care setting.

STUDY DESIGN

Four hundred three patients with intact amniotic membranes and cervical dilation ≤3 cm, without recent intercourse or cerclage, between gestational weeks of 20⁺⁰ and 36⁺⁶ were recruited prospectively from 3 international centers. Placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 tests were conducted before cervical length measurement via transvaginal ultrasound scanning. Caregivers were blinded to the biomarker test results. Medically indicated deliveries within 14 days of testing were excluded. Standard performance statistics with 95% confidence intervals were calculated and compared based on pairwise estimates from a generalized model.

RESULTS

Of 403 subjects who were enrolled in the study cohort, 94% (383/403 women) met the inclusion criteria. Median gestational age and cervical length at presentation were 30⁺⁵ weeks and 27 mm, respectively; 6.8% women (26/383 women) had spontaneous birth ≤7 days from testing. The placental alpha microglobulin-1 test was positive in 7.8% of the women (30/383 women); the phosphorylated insulin-like growth factor-binding protein-1 test was positive in 29.5% women (113/383 women). Positive predictive value for placental alpha microglobulin-1, phosphorylated insulin-like growth factor-binding protein-1, and cervical length <25 mm for the prediction of spontaneous preterm birth in the overall cohort was 60.0% (18/30 women), 18.6% (21/113 women), 11.8% (18/152 women), respectively. The negative predictive value was 97.7% (345/353 women), 98.2% (265/270 women), 96.5% (223/231 women), respectively. The prevalence of spontaneous preterm birth in this group was 6.8% (26/383 women). The positive likelihood ratios were 20.6, 3.1, and 1.8, respectively. The negative likelihood ratio were 0.3, 0.3, and 0.5, respectively. Positive predictive values for placental alpha microglobulin-1 and phosphorylated insulin-like growth factor-binding protein-1 tests in patients with cervical length shortening of 15-30 mm for the prediction of spontaneous preterm birth were 60.9% (14/23 women) and 28.1% (16/57 women), respectively. The negative predictive values were 97.1% (168/173 women) and 97.8% (136/139 women), respectively. The prevalence of spontaneous preterm birth in the 15-30 mm cohort was 9.7% (19/196 women). The positive likelihood ratios were 14.5 and 3.6, respectively. The negative likelihood ratios were 0.3 and 0.2, respectively.

CONCLUSION

Placental alpha microglobulin-1 is significantly more specific than phosphorylated insulin-like growth factor-binding protein-1 for the prediction of spontaneous preterm birth ≤7 days (P<.0001), whereas both tests have comparable sensitivity. In patients with cervical length 15-30 mm, although placental alpha microglobulin-1 has a significantly higher positive predictive value and specificity compared with phosphorylated insulin-like growth factor-binding protein-1 for the prediction of spontaneous preterm birth at ≤7 days (P<.01), both tests have a comparable sensitivity and negative predictive value. In conclusion, placental alpha microglobulin-1 is a better predictor of imminent spontaneous preterm birth when compared with phosphorylated insulin-like growth factor-binding protein-1 alone or in combination with cervical length measurement. In patients with shortening of cervical length of 15-30 mm, the placental alpha microglobulin-1 test is a significantly better predictor of imminent spontaneous preterm birth within 7 days of testing than is phosphorylated insulin-like growth factor-binding protein-1.

Prediction of preterm delivery in symptomatic women using PAMG-1, fetal fibronectin and phIGFBP-1 tests: systematic review and meta-analysis

OBJECTIVE

To assess the accuracy of placental alpha microglobulin-1 (PAMG-1), fetal fibronectin (fFN) and phosphorylated insulin-like growth factor-binding protein-1 (phIGFBP-1) tests in predicting spontaneous preterm birth (sPTB) within 7 days of testing in women with symptoms of preterm labor, through a systematic review and meta-analysis of the literature. The test performance of each biomarker was also assessed according to pretest probability of sPTB ≤ 7 days.

METHODS

The Cochrane, MEDLINE, PubMed and ResearchGate bibliographic databases were searched from inception until October 2017. Cohort studies that reported on the predictive accuracy of PAMG-1, fFN and phIGFBP-1 for the prediction of sPTB within 7 days of testing in women with symptoms of preterm labor were included. Summary receiver-operating characteristics (ROC) curves and sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and positive (LR+) and negative (LR-) likelihood ratios were generated using indirect methods for the calculation of pooled effect sizes with a bivariate linear mixed model for the logit of sensitivity and specificity, with each diagnostic test as a covariate, as described by the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy.

RESULTS

Bivariate mixed model pooled sensitivity of PAMG-1, fFN and phIGFBP-1 for the prediction of sPTB ≤ 7 days was 76% (95% CI, 57-89%), 58% (95% CI, 47-68%) and 93% (95% CI, 88-96%), respectively; pooled specificity was 97% (95% CI, 95-98%), 84% (95% CI, 81-87%) and 76% (95% CI, 70-80%) respectively; pooled PPV was 76.3% (95% CI, 69-84%) (P < 0.05), 34.1% (95% CI, 29-39%) and 35.2% (95% CI, 31-40%), respectively; pooled NPV was 96.6% (95% CI, 94-99%), 93.3% (95% CI, 92-95%) and 98.7% (95% CI, 98-99%), respectively; pooled LR+ was 22.51 (95% CI, 15.09-33.60) (P < 0.05), 3.63 (95% CI, 2.93-4.50) and 3.80 (95% CI, 3.11-4.66), respectively; and pooled LR- was 0.24 (95% CI, 0.12-0.48) (P < 0.05), 0.50 (95% CI, 0.39-0.64) and 0.09 (95% CI, 0.05-0.16), respectively. The areas under the ROC curves for PAMG-1, fFN and phIGFBP-1 for sPTB ≤ 7 days were 0.961, 0.874 and 0.801, respectively.

CONCLUSIONS

In the prediction of sPTB within 7 days of testing in women with signs and symptoms of preterm labor, the PPV of PAMG-1 was significantly higher than that of phIGFBP-1 or fFN. Other diagnostic accuracy measures did not differ between the three biomarker tests. As prevalence affects the predictive performance of a diagnostic test, use of a highly specific assay for a lower-prevalence syndrome such as sPTB may optimize management. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

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.

Use of fetal fibronectin testing in women transferred for threatened preterm labour in remote far north Queensland

BACKGROUND

Threatened preterm labour is a common reason for medical transfer from remote communities; however, many transferred women do not deliver preterm. A tool for prediction of preterm birth such as fetal fibronectin may reduce transfers and related social and economic costs.

AIM

To review the use of fetal fibronectin testing in women transferred for threatened preterm labour from Cape York to Cairns Hospital between 2011 and 2015 and determine the role testing could play in reducing transfers and associated costs.

MATERIALS/METHODS

Records from the Royal Flying Doctor Service and Cairns Hospital were accessed. Women transferred solely for threatened preterm labour were included in the study. Fetal fibronectin testing, hospital admission, outpatient stays and birth outcome data were collated and analysed. Costs were assigned using the National Hospital Cost Data Collection, round 19.

RESULTS

Forty-seven women were included in the study; however, only 20 underwent fetal fibronectin testing. Transfer of 30 women who had either a negative test or were not tested but delivered at term resulted in 41 inpatient nights and 443 excess outpatient nights, costing an estimated AU$57 408. Aeromedical transfers were estimated to cost a further $151 500.

CONCLUSION

Adherence to clinical guidelines and greater availability and use of fetal fibronectin testing in Cape York have the potential to reduce aeromedical transfers for threatened preterm labour. Substantial inpatient and excess outpatient stays could be avoided with associated reduction in health system and social costs. Strategies to improve adherence to guidelines and increase access to testing are required.

Quantitative fetal fibronectin and cervical length in symptomatic women: results from a prospective blinded cohort study. J Matern Fetal Neonatal Med 2018;32:3792-3800. [PMID: 29727248 DOI: 10.1080/14767058.2018.1472227]

Objectives: Our objectives were to determine whether quantitative fetal fibronectin (fFN) and cervical length (CL) screening can be used alone or in combination as prognostic tests to identify symptomatic women at the highest or lowest risk for spontaneous preterm birth (sPTB). Methods: A prospective, blinded cohort study of women presenting with a singleton gestation to our triage unit between 22-33w6d with preterm labor symptoms was performed. Women with ruptured membranes, moderate/severe bleeding, and dilation >2 cm were excluded. The primary outcome was sPTB <37 weeks. We evaluated test characteristics of quantitative fFN and CL assessment, both separately and in combination, considering traditionally reported cut-points (fFN ≥50 and CL <25), as well as cut-points above and below these measures. We found interactions between fFN >50 and CL <25 and sPTB by parity and obstetric history (p < .05) and therefore stratified results. Test characteristics are presented with positive predictive value (PPV) and negative predictive value (NPV). Results: Five hundred eighty women were enrolled and 537 women were available for analysis. Overall sPTB rate was 11.1%. Among nulliparous women, increasing levels of fFN were associated with increasing risk of sPTB, with PPV going from 26.5% at ≥20 ng/mL to 44.4% at ≥200 ng/mL. A cut-point of 20 ng/mL had higher sensitivity (69.2%) and higher NPV (96.8%) and therefore identified a "low-risk" group. fFN was not informative for multiparous women regardless of prior obstetrical history or quantitative level chosen. For all women, a shorter CL was associated with an increased sPTB risk. Among nulliparas and multiparas without a prior sPTB, a CL <20 mm optimized test characteristics (PPV 25 and 20%, NPV 95.5, and 92.7%, respectively). For multiparas with a prior sPTB, CL <25 mm was more useful. Using fFN and CL in combination for nulliparas did not improve test characteristics over using the individual fFN (p = .74) and CL (p = .31) components separately. Conclusions: This study identifies the importance of stratifying by parity and obstetrical history when using screening modalities for risk assessment in symptomatic women. For nulliparous women, either quantitative fFN or cervical length assessment can be utilized, depending on resources available, but a lower cut-point of 20 ng/mL should be used for quantitative fFN. For multiparous women, fFN is not useful and cervical length assessment should be the main screening tool utilized when there is clinical uncertainty. Regardless of parity, the PPV of fFN and CL is low and therefore the greatest clinical utility remains in its NPV.

Correlative study between C-reactive protein, clinical severity, and nerve conduction studies in Guillain-Barrè syndrome

Background

Guillain-Barre' syndrome (GBS) is a serious autoimmune disorder in which the immune system attacks healthy nerve cells of the peripheral nervous system causing polyradiculoneuropathy which leads to weakness, numbness, and tingling, and can eventually cause paralysis. Autoimmune conditions like GBS can induce a high level of inflammation resulting in an increase in the C-reactive protein( CRP) production. The aim of this study is to assess the relationship between CRP level and the clinical severity as well as the electrophysiological findings of nerve conduction studies in patients with GBS.

Methods

Twenty- four patients (10 males &14 females) with ages ranged from 14 to 50 years and a mean age of 33.46 ±12.25 years who fulfilled the clinical criteria for diagnosing GBS were recruited within the first 2 weeks of onset of illness, in a cross- section study. They underwent general and neurological examination. Nerve conduction studies as well as assessment of serum CRP level were done.

Results

There was a statistically significant positive correlation between clinical severity assessed by (Hughes disability scale) and serum CRP level in GBS patients. Multivariate logistic regression analysis showed that both gastroenteritis, cranio-bulbar affection, need for mechanical ventilation (MV), disability score >4, and absent motor and sensory responses were significantly associated with high serum CRP level >6mg/dl.

Conclusions

The results of this study support the hypothesis that in GBS patients, gastroenteritis, craniobulbar affection, need for MV, disability score >4, and absent motor and sensory nerve responses were significantly related to high serum CRP level. This reflects the negative impact of the inflammatory response elicited by high CRP level on clinical severity in GBS patients, and so it may be used as a prognostic marker of clinical severity of GBS and this can help in therapeutic decision making.

Quantitative fibronectin to help decision-making in women with symptoms of preterm labour (QUIDS) part 1: Individual participant data meta-analysis and health economic analysis

INTRODUCTION

The aim of the QUIDS study is to develop a decision support tool for the management of women with symptoms and signs of preterm labour, based on a validated prognostic model using quantitative fetal fibronectin (qfFN) concentration, in combination with clinical risk factors.

METHODS AND ANALYSIS

The study will evaluate the Rapid fFN 10Q System (Hologic, Marlborough, Massachusetts) which quantifies fFN in a vaginal swab. In part 1 of the study, we will develop and internally validate a prognostic model using an individual participant data (IPD) meta-analysis of existing studies containing women with symptoms of preterm labour alongside fFN measurements and pregnancy outcome. An economic analysis will be undertaken to assess potential cost-effectiveness of the qfFN prognostic model. The primary endpoint will be the ability of the prognostic model to rule out spontaneous preterm birth within 7 days. Six eligible studies were identified by systematic review of the literature and five agreed to provide their IPD (n=5 studies, 1783 women and 139 events of preterm delivery within 7 days of testing).

ETHICS AND DISSEMINATION

The study is funded by the National Institute of Healthcare Research Health Technology Assessment (HTA 14/32/01). It has been approved by the West of Scotland Research Ethics Committee (16/WS/0068).

PROSPERO REGISTRATION NUMBER

CRD42015027590.

VERSION

Protocol version 2, date 1 November 2016.

Electrohysterography in the diagnosis of preterm birth: a review

Preterm birth (PTB) is one of the most common and serious complications in pregnancy. About 15 million preterm neonates are born every year, with ratios of 10-15% of total births. In industrialized countries, preterm delivery is responsible for 70% of mortality and 75% of morbidity in the neonatal period. Diagnostic means for its timely risk assessment are lacking and the underlying physiological mechanisms are unclear. Surface recording of the uterine myoelectrical activity (electrohysterogram, EHG) has emerged as a better uterine dynamics monitoring technique than traditional surface pressure recordings and provides information on the condition of uterine muscle in different obstetrical scenarios with emphasis on predicting preterm deliveries.

OBJECTIVE

A comprehensive review of the literature was performed on studies related to the use of the electrohysterogram in the PTB context.

APPROACH

This review presents and discusses the results according to the different types of parameter (temporal and spectral, non-linear and bivariate) used for EHG characterization.

MAIN RESULTS

Electrohysterogram analysis reveals that the uterine electrophysiological changes that precede spontaneous preterm labor are associated with contractions of more intensity, higher frequency content, faster and more organized propagated activity and stronger coupling of different uterine areas. Temporal, spectral, non-linear and bivariate EHG analyses therefore provide useful and complementary information. Classificatory techniques of different types and varying complexity have been developed to diagnose PTB. The information derived from these different types of EHG parameters, either individually or in combination, is able to provide more accurate predictions of PTB than current clinical methods. However, in order to extend EHG to clinical applications, the recording set-up should be simplified, be less intrusive and more robust-and signal analysis should be automated without requiring much supervision and yield physiologically interpretable results.

SIGNIFICANCE

This review provides a general background to PTB and describes how EHG can be used to better understand its underlying physiological mechanisms and improve its prediction. The findings will help future research workers to decide the most appropriate EHG features to be used in their analyses and facilitate future clinical EHG applications in order to improve PTB prediction.