Positive Fetal Fibronectin Test Research Articles

Vaginal progesterone for the prevention of preterm birth: who can benefit and who cannot? Evidence-based recommendations for clinical use.

Vaginal progesterone (VP) has been recommended to prevent preterm birth (PTB) in women at high-risk. However, there is controversy as to whether VP is efficacious in some subsets of high-risk women. In this review, we examined the current best evidence on the efficacy of VP to prevent PTB in several subsets of high-risk women and provided recommendations for its clinical use. Compelling evidence indicates that VP reduces the risk of PTB and improves perinatal outcomes in singleton gestations with a short cervix (≤25mm), both with and without a history of spontaneous PTB. VP appears promising to reduce the risk of PTB in twin gestations with a short cervix (≤25mm) and in singleton gestations conceived by assisted reproductive technologies, but further research is needed. There is no convincing evidence that supports prescribing VP to prevent PTB in singleton gestations based solely on the history of spontaneous preterm birth. Persuasive evidence shows that VP does not prevent PTB nor does it improve perinatal outcomes in unselected twin gestations and in singleton gestations with a history of spontaneous PTB and a cervical length >25mm. There is no evidence supporting the use of VP to prevent PTB in triplet or higher-order multifetal gestations, singleton gestations with a positive fetal fibronectin test and clinical risk factors for PTB, and gestations with congenital uterine anomalies or uterine leiomyoma. In conclusion, current evidence indicates that VP should only be recommended in singleton gestations with a short cervix, regardless of the history of spontaneous PTB.

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

ABSTRACTObjectiveTo assess the association between preterm birth and cervical length after arrested preterm labor in high‐risk pregnant women.MethodsIn 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.ResultsA 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.ConclusionOur 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.

Does Fetal Fibronectin Predict the Delivery Route in Nulliparous Women at Postterm Induced by Dinoprostone?

Objective: Digital cervical evaluation has been used to determine the likelihood of vaginal delivery which is considered by many women to be non-tolerable. Recently, alternative approaches such as transperineal ultrasound, fetal fibronectin test in cervicovaginal secretions have been investigating for the prediction of the delivery route. We aimed to study whether the usefulness of qualitative fetal fibronectin test in cervicovaginal secretions for the prediction of vaginal delivery in pregnant women at postterm induced with dinoprostone.Study design: A total of 32 nulliparous pregnant women at postterm were enrolled in this prospective observational study. Fetal fibronectin test was applied to all participated women before the induction with dinoprostone and transvaginal ultrasonography was performed to measure cervical length.Results: The women having positive fetal fibronectin test result gave birth through vaginal route, except one case. Although there is no statistically significant difference, the shorter cervical length was associated with vaginal delivery in our population.Conclusion: Fetal fibronectin test has a predictive value for delivery route in nulliparous women at postterm. Fetal fibronectin test may be used as a “rule out” test because the rate of fetal fibronectin positivity was found to be higher in patients who gave birth via vaginal route. As also shown in our study, although there is no statistically significant difference, the pregnant women with shorter cervical length might have a high possibility to achieve vaginal delivery.

Cervical Pessary After Arrested Preterm Labor: A Randomized Controlled Trial.

To assess the effectiveness of cervical pessary in reducing the rate of preterm birth in women at high risk for preterm birth who did not deliver after an episode of threatened preterm labor. In a multicenter open-label randomized controlled trial, a cervical pessary was compared with no intervention (control group) (one-to-one ratio). Women between 24 and 34 weeks of gestation at high risk for preterm birth based on a short cervical length (less than 15 mm) or an intermediate cervical length (between 15 and 30 mm) with a positive fetal fibronectin test who did not deliver after an episode of threatened preterm labor were eligible. The primary outcome was birth before 37 weeks of gestation. Secondary outcomes were a composite adverse neonatal outcome, preterm birth before 34 and 32 weeks of gestation, and side effects. A total sample size of 200 women carrying singletons was planned so as to have adequate statistical power to detect a reduction in the rate of preterm birth from 40% to 20%. Women with twin gestations were also enrolled but were considered only in secondary analyses. After a planned interim analysis, the trial was stopped for futility. From November 2013 through September 2016, 130 women with a singleton pregnancy (65 pessary, 65 no treatment) were recruited. The groups had comparable baseline characteristics. In the cervical pessary group, 31 (48%) women delivered before 37 weeks of gestation compared with 25 (39%) in the no-treatment group (relative risk 1.2, 95% CI 0.83-1.8). Nine (15%) children in the cervical pessary group had the composite adverse perinatal outcome compared with eight (13%) in the control group (relative risk 1.2, 95% CI 0.49-2.9). In women at high risk for preterm birth who did not deliver after an episode of threatened preterm labor, treatment with a cervical pessary is not effective. Netherlands Trial Register, NTR4210.

Are Second Trimester Apparent Diffusion Coefficient Values of the Short Uterine Cervix Associated with Impending Preterm Delivery?

Purpose To prospectively determine whether the apparent diffusion coefficient (ADC) of the cervix is associated with preterm delivery in asymptomatic patients with a sonographic cervical length of 15 mm or less and positive fetal fibronectin test results between 23 and 28 weeks of gestation. Materials and Methods The institutional review board approved this prospective hypotheses-generating study. A total of 30 pregnant women (mean gestational age, 26 weeks) with a sonographic short cervix (≤15 mm) underwent pelvic 1.5-T magnetic resonance (MR) imaging. Oblique sagittal diffusion-weighted images were obtained with b values of 0, 400, and 800 sec/mm(2). ADC values at MR imaging of the subglandular and stromal cervix and the difference between both were correlated to the interval to delivery. Receiver operating characteristic curve analysis was performed to obtain sensitivity and specificity of ADC values in association with delivery within 7 days. Results Eight (27%) of 30 patients delivered within 6 or 7 days after MR imaging (impending delivery group), and 22 (73%) of 30 patients delivered between 18 and 89 days after imaging (mean, 55 days) (late delivery group). Mean subglandular ADC and mean ADC difference were higher (P < .001) in patients with impending delivery than in those with late delivery ([2406.3 ± 166.0] × 10(-6) mm(2)/sec vs [1708.9 ± 108.1] × 10(-6) mm(2)/sec and [657.3 ± 129.9] × 10(-6) mm(2)/sec vs [69.2 ± 70.2] × 10(-6) mm(2)/sec, respectively). Subglandular ADC inversely correlated with the interval between MR imaging and delivery (r = -0.75). Receiver operating characteristic curve analysis of subglandular ADC revealed 100% sensitivity (95% confidence interval: 63.1, 100) and 100% specificity (95% confidence interval: 84.6, 100) in association with impending delivery with a 1921 × 10(-6) mm(2)/sec threshold. Stromal ADC and sonographic cervical length showed no difference between groups (P = .072 and P = .511, respectively). Conclusion Cervical subglandular ADC at MR imaging is associated with impending preterm birth in patients with a short sonographic cervix. (©) RSNA, 2016.

Vaginal progesterone prophylaxis for preterm birth (the OPPTIMUM study): a multicentre, randomised, double-blind trial.

SummaryBackgroundProgesterone administration has been shown to reduce the risk of preterm birth and neonatal morbidity in women at high risk, but there is uncertainty about longer term effects on the child.MethodsWe did a double-blind, randomised, placebo-controlled trial of vaginal progesterone, 200 mg daily taken from 22–24 to 34 weeks of gestation, on pregnancy and infant outcomes in women at risk of preterm birth (because of previous spontaneous birth at ≤34 weeks and 0 days of gestation, or a cervical length ≤25 mm, or because of a positive fetal fibronectin test combined with other clinical risk factors for preterm birth [any one of a history in a previous pregnancy of preterm birth, second trimester loss, preterm premature fetal membrane rupture, or a history of a cervical procedure to treat abnormal smears]). The objective of the study was to determine whether vaginal progesterone prophylaxis given to reduce the risk of preterm birth affects neonatal and childhood outcomes. We defined three primary outcomes: fetal death or birth before 34 weeks and 0 days gestation (obstetric), a composite of death, brain injury, or bronchopulmonary dysplasia (neonatal), and a standardised cognitive score at 2 years of age (childhood), imputing values for deaths. Randomisation was done through a web portal, with participants, investigators, and others involved in giving the intervention, assessing outcomes, or analysing data masked to treatment allocation until the end of the study. Analysis was by intention to treat. This trial is registered at ISRCTN.com, number ISRCTN14568373.FindingsBetween Feb 2, 2009, and April 12, 2013, we randomly assigned 1228 women to the placebo group (n=610) and the progesterone group (n=618). In the placebo group, data from 597, 587, and 439 women or babies were available for analysis of obstetric, neonatal, and childhood outcomes, respectively; in the progesterone group the corresponding numbers were 600, 589, and 430. After correction for multiple outcomes, progesterone had no significant effect on the primary obstetric outcome (odds ratio adjusted for multiple comparisons [OR] 0·86, 95% CI 0·61–1·22) or neonatal outcome (OR 0·62, 0·38–1·03), nor on the childhood outcome (cognitive score, progesterone group vs placebo group, 97·3 [SD 17·9] vs 97·7 [17·5]; difference in means −0·48, 95% CI −2·77 to 1·81). Maternal or child serious adverse events were reported in 70 (11%) of 610 patients in the placebo group and 59 (10%) of 616 patients in the progesterone group (p=0·27).InterpretationVaginal progesterone was not associated with reduced risk of preterm birth or composite neonatal adverse outcomes, and had no long-term benefit or harm on outcomes in children at 2 years of age.FundingEfficacy and Mechanism Evaluation (EME) Programme, a Medical Research Council (MRC) and National Institute for Health Research (NIHR) partnership. The EME Programme is funded by the MRC and NIHR, with contributions from the Chief Scientist Office in Scotland and National Institute for Social Care and Research in Wales.

LB2: Opptimum

OPPTIMUM aimed to determine whether progesterone prophylaxis to prevent preterm birth in women at risk improves outcomes. In a double blind RCT, 1228 women at risk of preterm birth (due to a positive fetal fibronectin test, or a history of spontaneous preterm birth at ≤ 34+0 weeks gestation, or a cervical length ≤ 25mm) were randomized to vaginal progesterone, 200mg daily, or placebo, taken from 22-24 to 34 weeks gestation. Primary outcomes were (obstetric) preterm birth or fetal death before 34 weeks gestation, (neonatal) death or major morbidity (brain injury or bronchopulmonary dysplasia) and (childhood) Bayley III cognitive scores at 2 years of age, with values imputed for deaths. Analysis was by intention to treat using logistic, proportional hazards or linear regression, adjusting for previous pregnancy of ≥ 14 weeks (where possible), with study centre as a random effect. Progesterone had no statistically significant effect on either the primary obstetric or the childhood outcome (see table). Progesterone prophylaxis reduced the rate of the adverse neonatal composite outcome OR: 0.62 (95% CI 0.41, 0.94). However, following the pre-specified multiple comparisons procedure, this reduction was not statistically significant (adjusted p=0.072). Secondary analysis of the components of the neonatal outcome showed that progesterone reduced the risk of brain injury and neonatal death but not severe chronic lung disease. In the largest study of vaginal progesterone to date, we have not conclusively demonstrated reductions in preterm birth before 34 weeks or in neonatal morbidity. Progesterone appears to confer no long-term benefit or harm on cognitive and/or neurosensory outcomes in children at two years of age.

The NIFTY study: A multicentre randomised double‐blind placebo‐controlled trial of nifedipine maintenance tocolysis in fetal fibronectin‐positive women in threatened preterm labour

In an unselected group of women with signs of preterm labour, maintenance tocolysis is not effective in the prevention of preterm birth and does not improve neonatal outcome. Among women with signs of preterm labour, those who are fetal fibronectin positive have an increased risk of preterm birth. We investigated whether maintenance tocolysis with nifedipine would delay delivery and improve neonatal outcome in women with threatened preterm labour and a positive fetal fibronectin status. Women with a singleton pregnancy in threatened preterm labour (24(+0) to 33(+6) weeks) with a positive fetal fibronectin test were randomised to nifedipine or placebo. Study medication was continued until 36 completed weeks' gestation. The primary endpoint was prolongation of pregnancy of sevendays. Secondary endpoints were gestational age at delivery and length of NICU admission. Of the 60 participants, 29 received nifedipine and 31 placebo. Prolongation of pregnancy by >7days occurred in 22/29 (76%) in the nifedipine group and 25/31 (81%) in the placebo group (relative risks, RR 0.94 [0.72-1.2]). Gestational age at delivery was 36.1±5.1weeks for nifedipine and 36.8±3.6weeks for placebo (P=0.027). Length of NICU admission [median (interquartile ranges, IQR)] was 27 (24-41) days and 16 (8-37) days in nifedipine and placebo groups, respectively (P=0.17). In women with threatened preterm labour who are fetal fibronectin positive, maintenance tocolysis with nifedipine does not seem to prolong pregnancy, nor reduce length of NICU admission.

Prediction of preterm birth in twins

About 13% of twins are born before 34 weeks and 7% before 32 weeks. The prediction of preterm birth in twins is based on the same tests as in singleton pregnancies. In twin pregnancies, the cut-off for short cervix at the second trimester scan is less than 25 mm (compared with 15 mm in singletons); length less than 20 mm is associated with 42% risk for birth before 32 weeks and cervical length less than 25 mm is associated with 28% risk for birth before 28 weeks. The measurement of cervical length in pregnancies with symptoms of preterm labour may have limited accuracy in predicting preterm birth. In asymptomatic women, a positive fetal fibronectin test seems to be associated with 35% risk for birth before 32 weeks and 40% risk for birth less than 34 weeks, whereas a negative test decreases the risk to 6% and 17%, respectively. The differences in the predictive value of tests between twins and singletons reflect the diverse pathophysiology of preterm birth between the two groups.

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.

Effect of Antibiotic Exposure on Nugent Score Among Pregnant Women With and Without Bacterial Vaginosis

To evaluate whether vaginal flora is altered by antibiotic exposure and associated with a risk of preterm birth, particularly among women with initially normal vaginal flora. This was a secondary analysis of a randomized trial of metronidazole and erythromycin for the prevention of preterm birth among women with a positive fetal fibronectin test. Vaginal swabs for Nugent Gram stain score were collected for classification of bacterial vaginosis before and after antibiotic exposure and read at a central laboratory. Change in Nugent score was assessed for women with (score 7 or higher) or without (score lower than 7) bacterial vaginosis. Linear regression analysis evaluated whether change in Nugent score was associated with preterm birth. Two hundred women without and 69 women with bacterial vaginosis had Gram stain performed before and after antibiotic therapy. Median Nugent score for all women declined from 4.0 to 2.0 after antibiotic therapy (P<.001). Nugent score declined both for those without (from 2.0 to 1.5, P=.11) and, more dramatically, those with bacterial vaginosis (from 8.0 to 3.0, P<.01). The components of the Nugent score that were affected by antibiotic exposure were similar among women with and without bacterial vaginosis. Antibiotic exposure and the change in Nugent score were unrelated to preterm birth among bacterial vaginosis-negative women. Antibiotic exposure is not associated with preterm birth and does not worsen Nugent score among women with normal vaginal flora and positive fetal fibronectin. II.

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.

Effect of clindamycin treatment on vaginal inflammatory markers in pregnant women with bacterial vaginosis and a positive fetal fibronectin test

Objective To compare the levels of interleukin (IL)-1β, IL-6, and matrix metalloproteinase (MMP)-8 in the vaginal secretions of pregnant women with a positive fetal fibronectin (fFN) test result with or without asymptomatic bacterial vaginosis (BV) before and after treatment with oral clindamycin. Methods A prospective cohort study was conducted among 43 pregnant women with a positive fFN test result. All patients were treated with clindamycin, and the pre- and post-treatment levels of IL-1β, IL-6, and MMP-8 were compared. Results Before treatment, levels of IL-1β and MMP-8 were significantly higher in women with BV compared with women without BV ( P < 0.05). Vaginal levels of IL-1β and IL-6, but not MMP-8, decreased after treatment in pregnant women with BV. Conclusions The inability of clindamycin to decrease MMP-8 vaginal levels may explain why it is ineffective in reducing preterm birth in pregnant women with positive fFN and BV.

Obstetrician-gynecologists' knowledge of preterm birth frequency and risk factors

Objectives. To assess obstetrician-gynecologists' knowledge of preterm birth, including prevalence, risk factors, and utility of various tests in predicting increased risk.Methods. A questionnaire was mailed to 1193 members of the American College of Obstetricians and Gynecologists.Results. The response rate was 59%. The majority of respondents were familiar with basic preterm birth prevalence rates. However, 21% underestimated the proportion of women with presumptive preterm labor in whom preterm birth will not occur. The majority (55%) overestimated the proportion of preterm births accounted for by multiples. Twelve percent indicated bed rest as a proven method for improving newborn outcome. Respondents were fairly accurate as to which factors produce the biggest increased risk of spontaneous preterm labor or rupture of membranes; however, they tended to overestimate the risk associated with smoking, hypertension, and non-gestational diabetes. They tended to underestimate, or were unsure of, the predictive value of positive fetal fibronectin (fFN) test results or short cervical length.Conclusions. Obstetrician-gynecologists' basic knowledge concerning preterm birth prevalence and risk factors was adequate. However, they tended to overestimate the risk associated with various maternal factors and underestimate the predictive value of various test results.

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.

Antibiotic treatment after a positive fetal fibronectin test at mid-trimester did not prevent spontaneous preterm delivery

Antibiotic treatment after a positive fetal fibronectin test at mid-trimester did not prevent spontaneous preterm delivery

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.

A positive fetal fibronectin test is associated with more favorable induction of labor outcomes

A positive fetal fibronectin test is associated with more favorable induction of labor outcomes

Prediction of successful induction of labor at term: role of clinical history, digital examination, ultrasound assessment of the cervix, and fetal fibronectin assay

Objective The purpose of this study was to evaluate whether biochemical (fetal fibronectin assay) or biophysical (cervical assessment by transvaginal ultrasound) tests may have more value than digital examination in predicting successful induction of labor at term. Study design The study enrolled prospectively 134 women undergoing labor induction at term caused by several obstetric conditions. All participants submitted to digital examination, fetal fibronectin assay, and transvaginal ultrasound for measurement of the cervical length and detection of funneling. The performance of each test in predicting delivery within 24 hours of labor induction was evaluated. Cox multiple regression analysis was performed to identify, among clinical and laboratory tests, which variables were independently associated with the duration of the latent phase and with the total duration of induced labor. Results The likelihood ratios for positive results (predicting that delivery would occur within 24 hours) were 6.61 (95% CI, 1.7-25.8) for a positive obstetric history (previous vaginal delivery), 2.61 (95% CI, 1.6-4.3) for a “favorable” digital examination, 1.41 (95% CI, 0.9-2.2) for a positive fetal fibronectin test, 1.61 (95% CI, 0.9-3.0) for cervical length, and 2.20 (95% CI, 1.1-4.4) for the presence of funneling at transvaginal ultrasound. The likelihood ratios for negative results were 1.81 (1.3-2.5) for obstetric history, 4.34 (2.5-7.7) for digital examination, 1.41 (0.9-2.1) for fetal fibronectin, 1.29 (1.0-1.7) for cervical length, and 1.48 (1.1-2.0) for funneling. On multiple regression, the only variables independently associated with the duration of the latent phase and with the total duration of induced labor were obstetric history and digital examination. Conclusion Only obstetric history and digital examination predicted accurately vaginal delivery within 24 hours and were independently associated with labor duration. Fetal fibronectin and ultrasound measurements failed to predict accurately the outcome of induced labor.