Negative Fetal Fibronectin Research Articles

The diagnostic value of fetal fibronectin testing in clinical practice.

To evaluate the clinical management to withhold treatment for preterm labor in symptomatic women with an intermediate cervical length and negative fetal fibronectin (fFN) testing. A retrospective cohort study was performed in a tertiary care teaching hospital in the Netherlands. Pregnant women with a gestational age between 23+5 to 34+0 weeks, with the presence of regular uterine contractions accompanied by a cervical length between 15 and 30 mm and intact membranes, who underwent fFN testing were included to obtain the diagnostic value of fFN testing for preterm delivery within 7 days. Fetal fibronectin testing has an extremely high negative predictive value (100%) and sensitivity (100%) for delivery within 7 days, in singleton and multiple pregnancies. However, specificity (64%) and positive predictive value (10%) of fFN testing in singleton pregnancies are low. Blood present on the fFN sample does not affect the reliability of the fFN test; the negative predictive value remains 100%. Women with symptoms of early preterm labor, intact membranes, a cervical length between 15 and 30 mm and negative fFN testing do not deliver within 7 days. Administration of corticosteroids and tocolytics can safely be withhold. Furthermore, blood on the fFN sample does not change the reliability of the fFN test.

Fetal fibronectin testing for reducing the risk of preterm birth.

Fetal fibronectin (FFN) is an extracellular matrix glycoprotein localized at the maternal-fetal interface of the amniotic membranes, between chorion and decidua, where it is concentrated in this area between decidua and trophoblast. In normal conditions, FFN is found at very low levels in cervicovaginal secretions. Levels greater than or equal to 50 ng/mL at or after 22 weeks have been associated with an increased risk of spontaneous preterm birth. In fact, FFN is one of the best predictors of preterm birth in all populations studied so far, and can help in selecting which women are at significant risk for preterm birth. This is an update of a review first published in 2008. To assess the effectiveness of management based on knowledge of FFN testing results for preventing preterm birth. For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register (7 September 2018), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (7 September 2018), and reference lists of retrieved studies. Randomized controlled trials of pregnant women screened with FFN for risk of preterm birth. Studies included are based exclusively on knowledge of FFN results versus no such knowledge, and we have excluded studies including women with only positive or only negative FFN results. Two review authors independently assessed trials for inclusion and risk of bias, extracted data, and checked them for accuracy. The quality of the evidence was assessed using the GRADE approach. We identified 16 trials, of which six were eligible for inclusion. The six included studies randomized 546 women with singleton gestations and threatened preterm labor (PTL) at 23 0/7 to 34 6/7 weeks. A total of 277 women were randomized to knowledge and 269 to no knowledge of FFN. No trials were identified on asymptomatic women or multiple gestations.The risk of bias of included studies was mixed. For selected important outcomes, preterm birth before 37, 34, and 32 weeks, and maternal hospitalization, we graded the quality of the evidence and created a 'Summary of findings' table. For these outcomes, the evidence was graded as mainly low quality due to the imprecision of effect estimates.Management based on knowledge of FFN results may reduce preterm birth before 37 weeks (21.6%) versus controls without such knowledge (29.2%) (risk ratio (RR) 0.72, 95% confidence interval (CI) 0.52 to 1.01; 4 trials; 357 women; low-quality evidence). However, management based on knowledge of FFN results may make little or no difference to preterm birth before 34 (RR 1.09, 95% CI 0.54 to 2.18; 4 trials; 357 women; low-quality evidence) or maternal hospitalization (RR 1.06, 95% CI 0.79 to 1.43; 5 trials; 441 women; low-quality evidence). The evidence for preterm birth before 32 weeks is uncertain because the quality was found to be very low (average RR 0.79, 95% CI 0.16 to 3.96; 4 trials; 357 women; very low-quality evidence).For all other outcomes, for which there were available data (preterm birth less than 28 weeks; gestational age at delivery (weeks); birthweight less than 2500 g; perinatal death; tocolysis; steroids for fetal lung maturity; time to evaluate; respiratory distress syndrome; neonatal intensive care unit (NICU) admission; and NICU days), knowledge of FFN results may make little or no difference to the outcomes. The evidence from this review suggests that management based on knowledge of FFN results may reduce preterm birth before 37 weeks. However, our confidence in this result is limited as the evidence was found to be of low quality. Effects on other substantive outcomes are uncertain due to serious concerns in study design, inconsistency, and imprecision of effect estimates. No trials were identified on asymptomatic women, or multiple gestations.Future studies are needed that include specific populations (e.g. singleton gestations with symptoms of preterm labor), a study group managed with a protocol based on the FFN results, and that report not only maternal but also important perinatal outcomes. Cost-effectiveness analyses are also needed.

Randomized comparison of nifedipine and placebo in fibronectin-negative women with symptoms of preterm labor and a short cervix (APOSTEL-I Trial).

To evaluate whether tocolysis with nifedipine can be omitted in women with symptoms of preterm labor, a shortened cervix, and negative fetal fibronectin test. A randomized noninferiority trial was performed in all Dutch perinatal centers. Women with symptoms of preterm labor between 24 and 34 weeks, intact membranes, cervical length between 10 and 30 mm, and negative fibronectin test were randomly allocated to nifedipine (80 mg/day) or placebo. The primary outcome was delivery within 7 days. Secondary outcomes were severe neonatal morbidity and mortality. We also followed all eligible nonrandomized women. We allocated 37 women to nifedipine and 36 women to placebo. In the nifedipine group, three women (8.1%) delivered within 7 days, compared with one woman (2.8%) in the placebo group (difference -5.3%; one-sided 95% confidence limit 4.5%). Median gestational age at delivery were respectively 37 + 0 (interquartile range [IQR] 34 + 6 to 38 + 5) and 38 + 2 (IQR 37 + 0 to 39 + 6) weeks (p = 0.008). In the nifedipine group, three pregnancies (8.1%) had a poor outcome; there were no poor outcomes in the placebo group. We observed similar trends in eligible nonrandomized women. In symptomatic women with preterm labor, a shortened cervix, and negative fibronectin test, placebo treatment is not inferior to tocolysis with nifedipine.

The use of fetal fibronectin in suspected pre-term labour

Pre-term delivery is the leading cause of neonatal mortality and morbidity. The aim of this study is to determine the diagnostic accuracy of the fetal fibronectin (FF) test in predicting pre-term birth, the test interpretation and subsequent action taken in normal clinical practice in a busy tertiary centre setting. A total of 133 symptomatic women were included in the study and underwent the FF test. The use of tocolysis and corticosteroids were significantly greater in test-positive patients (p < 0.001). A negative test for detecting pre-term delivery within 10 days of the test was 100% sensitive with 100% negative predictive value (NPV). Our study has confirmed that a negative FF is an excellent short-term test to exclude pre-term delivery. The use of FF testing in routine clinical practice results in test characteristics similar to those found in research studies. This implies that the conclusions reached by researchers can be reliably translated into clinical practice.

Fetal fibronectin test on Chinese women with symptoms of preterm labour: a pilot study

The fetal fibronectin test is advocated to facilitate the management of women presenting with threatened preterm labour, but is underutilised in Hong Kong. This study aimed to provide experience with this test and evaluate its utility in a local setting. Prospective cohort study. A university-affiliated hospital in Hong Kong. Women presenting with symptoms of preterm labour were recruited from 1 January 2011 to 30 June 2012. The sensitivity, specificity, positive predictive value, and negative predictive value of the fetal fibronectin test to predict delivery within 24 hours, 48 hours, 7 days, and 14 days. A total of 22 women were recruited; 12 (55%) of whom had a negative fetal fibronectin test, none of whom delivered within 7 days; six received corticosteroids and tocolysis, one of whom delivered within 14 days. The 10 remaining women had a positive fetal fibronectin test. Five of whom delivered within 7 days and two within 14 days; all of them had received corticosteroids and tocolysis. For predicting delivery within 7 days, the sensitivity and negative predictive value of the test were both 100%. Our study demonstrated the high negative predictive value of the fetal fibronectin test in our local setting, which suggests that it should be utilised more readily in women presenting with threatened preterm labour.

Does the use of fetal fibronectin in an algorithm for preterm labor reduce triage evaluation times?

Objective: To determine the effectiveness of a novel algorithm based on fetal fibronectin (FFN) for management of preterm labor (PTL).Methods: A randomized trial was performed on patients who presented with symptoms of PTL at 24–34 weeks. Patients were randomized to algorithms with cervical exams only versus cervical exams plus FFN. In this algorithm, physicians had to discharge patients with a negative FFN result. The primary outcome was the evaluation time for triage. The secondary outcomes were admission to the hospital for PTL, preterm birth <34 weeks and preterm birth <37 weeks.Results: A total of 76 patients were enrolled and randomized (control n = 32, FFN n = 44). There were no differences in triage time, hospital admissions or preterm deliveries (PTDs) between the two groups.Conclusion: An algorithm based on FFN for management of PTL does not reduce evaluation times for triage, hospital admissions or PTDs.

472: Do pregnancies complicated by preterm births with a negative fetal fibronectin screen have different characteristics compared to those that have positive fibronectin results?

As a result of the high negative predictive value, there is limited data on pregnancies with a negative fetal fibronectin (fFN) test that deliver preterm. Our objective is to compare pregnancy characteristics between fFN positive and negative patients that delivered within 14 days of testing.

The clinical use of inflammatory markers during pregnancy

There is overwhelming evidence that intrauterine infection and inflammation play an important role in the pathogenesis of spontaneous preterm labor, preterm prelabor rupture of the membranes and fetal injury resulting in long-term sequelae. Early diagnosis of subclinical infection and inflammation may therefore aid clinicians institute interventions focusing on such adverse outcomes. Biomarkers of intrauterine inflammation such as interleukin-6, although sensitive, are not specific. Thus, decision to deliver remote from term because of intrauterine infection and/or inflammation should be based on clinical signs and/or bacterial culture or Gram stain of amniotic fluid. In patients with preterm contractions and intact membranes, the risk of delivery is 1% within the week following a negative fetal fibronectin in cervicovaginal secretions. This aids to decide whether antenatal steroids should be administered to patients presenting with preterm contractions between 24 and 34 weeks' gestation. Biomarkers in cervical secretions and amniotic fluid identify those who may benefit from cerclage when the cervix is shortened (<25 mm) and dilated in the second trimester. So far, few interventions utilizing inflammatory biomarkers have shown clinical benefit. Future efforts should focus on the quest for accurate biomarkers that can be obtained noninvasively and allow early prediction of subclinical disease to initiate appropriate risk-specific intervention.

Fetal Fibronectin as a Short-Term Predictor of Preterm Birth in Symptomatic Patients

To appraise critically the diagnostic accuracy of cervicovaginal fetal fibronectin as a short-term predictor of preterm birth in patients with signs and symptoms of preterm labor. We searched MEDLINE, Current Contents, Index Medicus, EMBASE, the Cochrane Library, and syllabi from scientific meetings, and we performed manual searches of references from textbooks and of known primary and systematic review articles. We also contacted authors, experts on this subject, and the manufacturer. We targeted cohort studies reporting data on the diagnostic accuracy of fetal fibronectin for the prediction of preterm birth within 7 days in symptomatic patients before 37 weeks of gestation. Case-control studies were excluded. The total analysis included 32 trials with 5,355 overall participants. Two authors independently assessed methodological quality and constructed 2x2 tables for assessment of diagnostic measures. Pooled estimates of sensitivity, specificity, and likelihood ratios were obtained using a bivariate random effects model. Tests for publication bias and meta-regression were performed. Sensitivity analyses were performed for studies using different fetal fibronectin assays. The overall pooled estimates for sensitivity and specificity were 76.1% (95% confidence interval [CI] 69.1-81.9) and 81.9% (95% CI 78.9-84.5), respectively. Likelihood ratios for a positive and negative fetal fibronectin test were 4.20 (95% CI 3.53-4.99) and 0.29 (95% CI 0.22-0.38), respectively. Meta-regression analyses found that test accuracy was affected by prevalence, publication year, and blinding of studies. When subgroup analyses were performed for studies using the same assay, the results were similar. The cervicovaginal fetal fibronectin assay has limited accuracy in predicting preterm birth within 7 days of sampling in symptomatic pregnant women.

128: Short cervix and negative fetal fibronectin: Low risk of delivery within 2 weeks of screening

128: Short cervix and negative fetal fibronectin: Low risk of delivery within 2 weeks of screening

Fetal fibronectin testing for reducing the risk of preterm birth

Fetal fibronectin (FFN) is an extracellular matrix glycoprotein localized at the maternal-fetal interface of the amniotic membranes, between chorion and decidua, where it is concentrated in this area between decidua and trophoblast. In normal conditions, FFN is found at very low levels in cervico-vaginal secretions. Levels greater than or equal to 50 ng/mL at or after 22 weeks have been associated with an increased risk of spontaneous preterm birth. In fact, FFN is one of the best predictors of preterm birth in all populations studied so far, and can help selecting which women are at significant risk for preterm birth. To assess the effectiveness of management based on knowledge of FFN testing results for preventing preterm birth. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2008), MEDLINE (1966 to December 2007) and all references in identified articles. Randomized controlled trials of pregnant women between the gestational ages of 22 and 34 weeks screened with FFN for risk of preterm birth. Studies included are based exclusively on knowledge of FFN results versus no such knowledge, and we have excluded studies including women with only positive or only negative FFN results. All four authors assessed studies for inclusion and quality and extracted data. We identified 13 trials, of which five were eligible for inclusion. The five included studies randomized 474 women, of which 235 were randomized to knowledge and 249 to no knowledge of FFN.Preterm birth less than 37 weeks was significantly decreased with management based on knowledge of FFN results (15.6%) versus controls without such knowledge (28.6%; risk ratio 0.54; 95% confidence interval 0.34 to 0.87). All other outcomes for which there were available data (preterm birth at less than 34, 32, or 28 weeks; gestational age at delivery; birthweight less than 2500 grams; perinatal death; maternal hospitalization; tocolysis; steroids for fetal lung maturity; and time to evaluate) were similar in the two groups. No other maternal or neonatal outcome was available for meaningful analysis. Although FFN is commonly used in labor and delivery units to help in the management of women with symptoms of preterm labor, currently there is not sufficient evidence to recommend its use. Since this review found an association between knowledge of FFN results and a lower incidence of preterm birth before 37 weeks, further research should be encouraged.

Negative fetal fibronectin: Who is still treating for threatened preterm labor and does it help?

Fetal fibronectin (fFN) has a high negative predictive value for delivery in the next seven days in patients at risk for preterm birth. Providers sometimes disregard a negative result and manage the patient for threatened preterm labor. Our objective was to identify the rate at which patients with a negative fFN were managed for threatened preterm labor and if delivery outcomes were improved with such management. Retrospective chart review of 111 patients at a single institution evaluated in the obstetrical triage unit for symptoms of threatened preterm labor with negative fFN results over a 19-month period between November 2004 and June 2006. Charts were reviewed for baseline patient characteristics such as gestational age at presentation to triage and fFN testing, prior obstetrical history, cervical examination and contraction frequency. Gestational age at delivery was documented. Rates of admission to the hospital and treatments for threatened preterm labor in this cohort were reviewed. Thirty-seven of patients (33%) with a negative fFN result were managed for threatened preterm labor (admitted to the hospital, given tocolytics, steroids, or intravenous antibiotics) by their provider. Patients undergoing these interventions were more likely to have cervical dilatation, effacement and were contracting more frequently. Only one of the patients delivered within 7 or 14 days of fFN testing. There was no advantage seen to management of threatened preterm labor in the setting of a negative fFN in terms of pregnancy prolongation, even when analyzing the patients with meaningful clinical findings (dilated 2 cm, effaced >or=80%, or contracting >or=12 times/h). Patients with meaningful clinical findings suspicious for preterm labor are more likely to undergo interventions by their physicians in the face of a negative fFN. This management does not improve length of gestation.

Comparison of Bedside Test Kits for Prediction of Preterm Delivery: Phosphorylated Insulin-like Growth Factor Binding Protein-1 (pIGFBP-1) Test and Fetal Fibronectin Test

The objective of the study was to compare the effectiveness of bedside test kits for pIGFBP-1 and fetal fibronectin test in predicting preterm delivery. Patients presenting with symptoms of preterm labour between 24 and 34 weeks of gestation were recruited. Both pIGFBP-1 and fetal fibronectin bedside tests were performed. Managing obstetricians and patients were blinded to the pIGFBP-1 and fetal fibronectin results. Tocolysis and steroid therapy were administered to all the recruited patients. Outcome data were collected after delivery. One hundred and eight patients were recruited into the study. Fourteen patients had to be excluded from the final analysis due to incomplete data and failure to meet inclusion criteria. Ninety-four patients had complete data for analysis. Among those with negative pIGFBP-1 and fetal fibronectin results, the median [+/-standard deviation (SD)] gestational age at delivery was 37.4 weeks (+/-2.8 weeks) and 37.4 weeks (+/-2.1 weeks), respectively. Among those with positive pIGFBP-1 and fetal fibronectin results, the median (+/-SD) gestational age at delivery was 32.9 weeks (+/-4.0 weeks) and 34.2 weeks (+/-4.2 weeks), respectively (P <0.001 for both pIGFBP-1 and fetal fibronectin). A positive result with either test was associated with a significantly reduced admission-to-delivery interval. The median admission-to-delivery interval was 2.8 weeks shorter in the group with positive pIGFBP-1 results compared to those with a negative pIGFBP-1 result (2.3 weeks compared with 5.1 weeks) (P <0.001). This is 1.8 weeks shorter in the group with positive fibronectin results, compared to those with a negative result (3.3 weeks compared with 5.1 weeks) (P=0.002). Both pIGFBP-1 and fetal fibronectin tests have high negative predictive value (NPV) in predicting risk of delivery within 48 hours, 7, or 14 days (1.00; 0.92; 0.92 and 0.97; 0.89; 0.89, respectively). Both pIGFBP-1 and fetal fibronectin tests are effective adjuvant bedside test kits for the prediction of preterm delivery in patients presenting with signs or symptoms of preterm labour. pIGFBP-1 has the higher NPV of 1.00 in predicting risk of delivery within 48 hours.

Performance of cervicovaginal fetal fibronectin in a community hospital setting

To assess the accuracy of vaginal fetal fibronectin (FFN) as a screening test for preterm delivery in a community hospital. A prospective cohort of patients at high risk for preterm delivery at a community hospital underwent testing with FFN over a 15 month-period (March 2004-May 2005). Indications for testing were preterm labor, multiple pregnancies, cervical shortening, and cerclage. Pregnancy characteristics were retrieved on all women with positive FFN results and controls in a 1:2 ratio. Outcome variables included interval to delivery; length of hospital stay; and rates of preterm delivery <37 weeks. In the presence of serial FFN testing, only the initial result was used for calculation of diagnostic indices. Statistical analysis utilized t-test, Fisher's exact test and logistic regression analysis to control for gestational age at testing, with P < 0.05 or odds ratio (OR) with 95% confidence interval (CI) not inclusive of the unity considered significant. Two hundred and fifty seven FFN tests were performed in 230 women, of which 33 (14.3%) had positive FFN results. Duration of hospital stay was significantly shorter for patients with negative than positive results (8 h vs. 2.1 days, P = 0.011). Women with positive FFN were more likely to deliver within 14 days (OR = 6.5, 95% CI 1.4; 30.7), within 21 days (OR = 4.8; 95% CI 1.4; 16.6), before 34 weeks (OR = 5.0, 95% CI 1.7; 14.8) and before 37 weeks (OR = 3.1; 95% CI 1.3; 7.1) than women with negative results. A negative FFN result provides enough reassurance to allow shorter hospital stay. In a real-world setting (a community hospital with a population heterogeneous for risk factors for preterm delivery, and in a non-protocol setting) the performance of FFN testing closely mirrors that obtained in academic institutions, where the test was studied in more uniform populations under strict protocols. The performance of vaginal fibronectin in patients with heterogeneous risk factors for preterm delivery closely mirrors that obtained in studies conducted in populations with homogeneous risk factors.

Impact of quantitative fetal fibronectin (FFN) change on efficacy of antibiotic vs. placebo treatment of asymptomatic FFN positive women to prevent subsequent preterm birth (PB)

ANTIBIOTIC VS. PLACEBO TREATMENT OF ASYMPTOMATIC FFN POSITIVE WOMEN TO PREVENT SUBSEQUENT PRETERM BIRTH (PB) MONIQUE LIN (F), for the NICHD MFMU Network, Bethesda, Maryland OBJECTIVE: To evaluate whether change in quantitative FFN concentration following antibiotic or placebo treatment of asymptomatic FFN positive women is related to subsequent PB !37 wks. STUDY DESIGN: Secondary analysis of a multicenter double blinded, placebo-controlled study of antibiotic therapy for asymptomatic women with a positive cervicovaginal FFN (R50 ng/mL) between 21-25 wks. Women were randomized to either metronidazole 250 mg tid C erythromycin 250 mg qid for 10 days or identical placebos. Quantitative FFN was assessed at baseline and 2 weeks after treatment. Preto post-treatment FFN changes (DFFN) were categorized as: 1) no change or increasing, 2) decreasing with persistent positive FFN at follow-up, and 3) decreasing with follow-up negative FFN. Primary study outcome was PB !37 wks. RESULTS: Of the 715 women enrolled, 591 had quantitative FFN values preand post-treatment and outcomes available. Race, gestational age, randomization to follow-up interval, pre-treatment FFN concentration, and BV status were similar between groups. A similar proportion of women were FFN positive at follow-up in the antibiotic group (22.5%) compared with placebo group (16.6%, p=0.07). Irrespective of treatment, rate of PB !37 wks was significantly associated with DFFN with the highest rate noted in women with no change or increased FFN (TABLE). Within each DFFN category, incidence of PB!37 wks between the two treatment groups was not significantly different (TABLE).

Fetal Fibronectin as a Predictor of Vaginal Birth in Nulliparas Undergoing Preinduction Cervical Ripening

We sought to evaluate whether the presence of a positive fetal fibronectin (> or = 50 ng/mL) in nulliparous women undergoing preinduction cervical ripening with the intracervical Foley catheter predicted vaginal birth. This was a prospective blinded observational trial of nulliparous women undergoing preinduction cervical ripening. We excluded women who had a contraindication to vaginal birth. Cervical and vaginal fetal fibronectin specimens were obtained before preinduction cervical ripening with an intracervical Foley catheter. The managing obstetrician was blinded to these results. A total of 241 women met the inclusion criteria, of which 54.4% delivered vaginally. There was no difference in the rate of vaginal delivery among women with either a positive cervical fetal fibronectin (positive fetal fibronectin 55.8% compared with negative fetal fibronectin 53.3%, P = .70) or positive vaginal fetal fibronectin (positive fetal fibronectin 57.6% compared with negative fetal fibronectin 53.3%, P = .56). Women with a positive cervical fetal fibronectin did have a shorter duration of cervical ripening (fetal fibronectin-positive 229 +/- 220 minutes compared with fetal fibronectin-negative 379 +/- 193 minutes, P < .05), duration of oxytocin (fetal fibronectin-positive 655 +/- 555 minutes compared with fetal fibronectin-negative 731.5 +/- 342 minutes, P < .025) and required lower maximal doses of oxytocin (fetal fibronectin-positive 18.4 mIU/min compared with fetal fibronectin-negative 21.8 mIU/min, P = .005). Women with a positive vaginal fetal fibronectin demonstrated only a shorter duration of cervical ripening compared with their fetal fibronectin negative counterparts (fetal fibronectin-positive 300 +/- 216 minutes compared with fetal fibronectin-negative 345 +/- 201 minutes, P < .05). Fetal fibronectin does not predict vaginal delivery in nulliparous women requiring preinduction cervical ripening. II-2.

Cervical fetal fibronectin as a predictor of first trimester pregnancy outcome in unexplained recurrent miscarriage

Objective To determine whether cervical fetal fibronectin is a reliable predictor of first trimester pregnancy outcome in patients with unexplained recurrent miscarriage. Study design A prospective observational study was carried out on 49 pregnant women with a history of unexplained recurrent miscarriage. In all participants the presence of fetal fibronectin in the cervical secretion was determined with a qualitative rapid immunoassay. The outcome of the first trimester pregnancy was recorded a successful outcome was a pregnancy that progressed beyond 12 weeks of gestation; a miscarriage referred to a pregnancy loss in the first 12 weeks. Results Of the 49 subjects screened, fetal fibronectin was positive in 17 and negative in 32. Overall, 14 pregnancies resulted in fetal loss before the 12th week of gestation. Fetal cervical fibronectin was positive in 6 of the 14 patients who miscarried and in 11 of the 35 in whom outcome was successful. As predictor of first trimester pregnancy outcome the test had a sensitivity and a specificity of 43% and 69% and positive and negative predictive values of 35%, and 75%, respectively. Subgroup analysis by number of previous miscarriages and maternal age gave similar values. Conclusion This study examines the possible value of cervical fetal fibronectin in predicting first trimester pregnancy outcome. We conclude that the occurrence of positive or negative fetal cervical fibronectin test has only limited predictive value and therefore its use cannot be considered for clinical application.

Fetal fibronectin as predictor of successful induction of mid‐trimester abortion

Fetal fibronectin (FFN) in cervical secretion is one of the most effective markers of pre-term and term delivery. The presence of FFN in cervicovaginal secretions has recently been shown to reflect cervical state and an uncomplicated induction of labor at term. This study was designed to determine whether FFN could be a biochemical marker to predict the response to prostaglandins in early mid-trimester abortion. The presence of cervical FFN was evaluated by means of qualitative rapid immunoassay in 270 patients, who required second trimester termination of pregnancy at the Department of Gynecology and Obstetrics, University of Naples 'Federico II'. According to the standard protocol of our unit, women received 1.0 mg of gemeprost intravaginally at 3-hr intervals up to a maximum of five suppositories. The induction-to-abortion interval and the percentage of successful abortions within 24 hr in women in the positive FFN group (n=19) were compared with those in the negative FFN group (n=251). FFN in the cervical secretions was present in seven women (10.2%) at 16-weeks gestation, in seven women (7.5%) at 17-weeks gestation, and in five women (4.5%) at 18-week gestation. Final termination rates were 13 (68.4%) in the fibronectin-positive group and 177 (70.5%) in the fibronectin-negative group. The median abortion interval was similar (14.7 versus 15.1 hr) in both groups. A positive cervical fetal fibronectin test does not predict a successful medical termination of pregnancy in second trimester abortion. In this setting, the role of fetal cervical fibronectin in cervical ripening is, therefore, questionable.

Assessment of Rapid Fetal Fibronectin in Predicting Preterm Delivery

The aim of this study was to estimate the effectiveness of cervical fetal fibronectin assayed by the rapid fetal fibronectin assay in predicting preterm delivery in patients with signs or symptoms of preterm labor. Patients with preterm labor between 24 and 34 weeks of gestation were included. At the time of speculum examination, fetal fibronectin samples were collected from the cervix. The probe was analyzed for fetal fibronectin using the rapid fetal fibronectin assay. Managing obstetricians were blinded to fetal fibronectin results. Outcome data were collected after delivery. One hundred seventy patients had fetal fibronectin samples and outcome data. The mean (+/- standard deviation) gestational age at delivery was 38.63 +/- 2.5 weeks among those with negative fetal fibronectin results (n = 124) and 35.71 +/- 3 weeks for those with positive results (n = 46; P < .001). The admission-to-delivery interval was 27.3 days shorter in the group with positive fetal fibronectin results (36.1 +/- 29.9 compared with 63.4 +/- 29.2; P < .001). The rapid fetal fibronectin assays were useful in predicting risk of delivery within 7, 14, or 21 days (sensitivity 81.8%, 87.5%, and 77.3%; specificity 76.7%, 79.2%, and 80.4; positive predictive value 19.6% [9/46], 30.4% [14/46], 37% [17/46]; negative predictive value 98.4% [122/124], 98.4% [122/124], and 96% [119/124], respectively). In a population of patients with signs and symptoms of preterm labor, the presence of cervical fetal fibronectin is effective in predicting risk of delivery within 7, 14, or 21 days. The negative predictive values of fetal fibronectin using the Tli systems compared well with data from previous reports using enzyme-linked immunosorbent assay-based assays. III.

Prospective randomized controlled trial of fetal fibronectin on preterm labor management in a tertiary care center

ObjectiveThe purpose of this study was to investigate the effect of the rapid fetal fibronectin on the length of hospital stay and the use of preterm labor interventions in a tertiary care center. Study designWomen who were seen in the Labor and Delivery Unit with symptoms of preterm labor were assigned randomly to receive fetal fibronectin (n=46 women) or to preterm labor management without fetal fibronectin (n=51 women). Physicians were not blinded to the result; groups were compared. ResultsThere was no difference between groups in demographic or obstetric characteristics, the hours spent in labor and delivery, the number of women who were admitted to the antepartum service, the length of stay, or medical interventions. When the results for women with a negative fetal fibronectin test were compared to women with a positive fetal fibronectin test, a significant difference was found in admissions to the antepartum service (P=.032) and the length of stay (P=.008). ConclusionsA negative fetal fibronectin test was associated with fewer admissions to the antepartum ward and a shorter length of stay.