Cervical Fetal Fibronectin Research Articles

The preterm prediction study: Patterns of cervicovaginal fetal fibronectin as predictors of spontaneous preterm delivery

OBJECTIVE: Our purpose was to determine how various temporal patterns of fetal fibronectin positivity from 24 to 30 weeks predict subsequent fetal fibronectin test results and spontaneous preterm delivery. STUDY DESIGN: A total of 2929 women had vaginal and cervical fetal fibronectin tests obtained at least once at 24, 26, 28, or 30 weeks, and 1870 women had tests performed at all four gestational ages. Fetal fibronectin values ≥50 ng/ml were considered positive. Various patterns of positive and negative tests were evaluated for prediction of (1) whether the next fetal fibronectin test would be positive or negative and (2) the percent of women with a spontaneous preterm delivery ≥4 weeks after the last fetal fibronectin test at <30, <32, <35, and <37 weeks' gestational age. RESULTS: Women with previous negative test results had only a 3% chance of a subsequent positive test result; however, if the last test result was positive, 29% of the next tests were positive. Of the 1870 women with tests at 24, 26, 28, and 30 weeks, 89% had all negative results, 8.4% had one positive result, 1.8% had two positive results, and 0.8% had three or four positive results. The higher the percent of positive tests at 24 to 26 weeks, at 28 to 30 weeks, or at 24 to 30 weeks, the greater the risk of subsequent spontaneous preterm birth. As an example, the risk of spontaneous preterm birth at <30 weeks for women with two negative fetal fibronectin test results at 24 and 26 weeks was 0.3% versus 16% for women with two positive results. CONCLUSION: The presence of a positive cervical or vaginal fetal fibronectin test result predicts subsequent positive fetal fibronectin positivity and subsequent spontaneous preterm birth. The greater the percent of positive results, the higher is the risk of spontaneous preterm birth. After a positive test result, two negative results are required before the risk of spontaneous preterm birth returns to baseline.(Am J Obstet Gynecol 1997;177:8-12.)

A single cervical fetal fibronectin screening test in a population at low risk for preterm delivery: an improvement on clinical indicators?

To assess the accuracy of a single cervical fetal fibronectin test to predict spontaneous preterm delivery in an unselected antenatal population. A prospective blind cohort study. Antenatal clinic of a teaching hospital in a Brussels semiurban area. An unselected group of 170 women followed at the antenatal clinic. A single cervical sample was obtained between 24 and 33 completed weeks of pregnancy. The fibronectin test was compared with clinical evaluation and their predictive properties were assessed. Fifteen women were excluded from the analysis because of elective preterm delivery for medical indications or loss to follow up. Of the 155 remaining women, nine (7%) had a spontaneous preterm delivery. For a single fetal fibronectin test, the sensitivity was 26.7%, the specificity 95.7%, and the positive and negative predictive values 40.0% and 92.4%, respectively. The likelihood ratio of a positive was similar to that of clinical predictors of preterm birth (LR = 6.2; 95% CI 2.0-19.6). Sensitivities were low for both clinical criteria and the fetal fibronectin test. Because of low sensitivity in a low risk population, screening for preterm delivery should not be based on the result of a single fetal fibronectin test alone. However, due to its high specificity the test might be useful in avoiding unnecessary medical intervention.

Cervical fetal fibronectin in patients at increased risk for preterm delivery: Bittar R.E.; Yamasaki A.A.; Sasaki S.; Zugaib M. BRA Am. J. Obstet. Gynecol. 1996 175/1 (178–181)

Cervical fetal fibronectin in patients at increased risk for preterm delivery: Bittar R.E.; Yamasaki A.A.; Sasaki S.; Zugaib M. BRA Am. J. Obstet. Gynecol. 1996 175/1 (178–181)

The preterm prediction study: Association between cervical interleukin-6 (IL-6), fetal fibronectin (FFN), and spontaneous preterm birth (SPTB)

The preterm prediction study: Association between cervical interleukin-6 (IL-6), fetal fibronectin (FFN), and spontaneous preterm birth (SPTB)

Value of fetal fibronectin as a predictor of preterm delivery for a low-risk population

OBJECTIVE: We examined clinical value of cervical fetal fibronectin detection by a quantitative enzyme-linked immunosorbent assay as a predictor of preterm delivery in a population (n = 111) of middle-class pregnant women considered to be at low risk for preterm delivery. STUDY DESIGN: In this prospective study, fetal fibronectin samples from cervicovaginal secretions were obtained biweekly from 24 to 34 weeks' gestation. RESULTS: Twenty-two (20%) patients had at least one positive fetal fibronectin test result. Eleven women (10%) were delivered spontaneously at <37 weeks; seven of these had at least one positive fetal fibronectin test result (positive predictive value = 31.8%, sensitivity = 63.6). An additional three women were delivered prematurely because of other obstetric indications, and all had negative fetal fibronectin test results. The remaining 15 patients with at least one positive fetal fibronectin test result were delivered at term (≥37 weeks). Of the seven women with positive fetal fibronectin results who were delivered prematurely, five were delivered within 2 weeks of obtaining a positive result. However, there were no obvious clinical discriminators between true-positive and false-positive fetal fibronectin results. Eighty-nine women tested negative, and 85 of these women were delivered at term (specificity = 82.0%). The negative predictive value of fetal fibronectin as a predictor of term delivery in this low-risk population is 96.6%, with odds ratio = 8.8 (95% confidence interval 1.9 to 40.3), relative risk = 6.9 (95% confidence interval 1.8 to 26.6), and Fisher Exact Test p = 0.007. CONCLUSIONS: Although negative biweekly fetal fibronectin determinations for prediction of preterm delivery in this low-risk obstetric population correlate well with the absence of preterm delivery, they are of limited clinical value for the prediction of preterm birth. (Am J Obstet Gynecol 1996;175:1054-6.)

Cervical fetal fibronectin in patients at increased risk for preterm delivery

OBJECTIVE: This study aimed to evaluate fetal fibronectin concentrations in cervical secretions measured by either a rapid immunoassay or an enzyme-linked immunosorbent assay as a tool for the screening of premature delivery in otherwise asymptomatic pregnant women at high risk for prematurity. STUDY DESIGN: One hundred two pregnant women at high risk for premature delivery were followed up. Samples of the cervical secretion were taken every 2 weeks between the twenty-fourth and the thirty-fourth weeks of pregnancy. The samples were obtained from the ectocervix with two swabs. One cervical sample was used for the immediate-reading membrane test, and the other one for the immunoenzyme test. The correlation between the presence of fetal fibronectin in the cervical secretions and preterm birth was evaluated. In addition, a comparison between tests was made. RESULTS: The rate of preterm birth was 37.25% (38/102). Membrane tests revealed a sensitivity of 73.68% and a specificity of 92.18%; its positive predictive value was 84.84% and the negative predictive value was 85.50%. The enzyme-linked immunosorbent assays revealed a sensitivity of 78.94% and a specificity of 85.93%; its positive predictive value was 76.92%, and the negative predictive value was 87.30%. When compared with each other, the tests were found essentially concordant ( p < 0.05). The elapsed time between the last sampling and the occurrence of preterm birth was 2.9 ± 1.8 weeks. CONCLUSION: The rapid result membrane test is comparable to the standard fetal fibronectin enzyme-linked immunosorbent assays for the detection of fetal fibronectin in cervical secretions between the twenty-fourth and thirty-fourth weeks of gestation. Moreover, both assays were found to be good tools for the prediction of premature delivery in asymptomatic pregnant women at high risk for prematurity. The availability of a rapid search for the presence of cervical fetal fibronectin should improve our ability to efficiently identify patients at risk for preterm delivery to discriminate between such patients and those with benign Braxton Hicks contractions. (Am J Obstet Gynecol 1996;175:178-81.)

Cervical Fetal Fibronectin Correlates to Cervical Ripening

Ekman, Gunvor; Granstrom, Lena; Malmstrom, Anders; Sennstrom, Maria; Svensson, Jan Author Information

The Preterm Prediction Study: Fetal Fibronectin, Bacterial Vaginosis, and Peripartum Infection

To determine the relation between vaginal and upper genital tract infection and cervical-vaginal fetal fibronectin levels. We screened 2899 women at ten centers every 2 weeks from 23-24 to 30 weeks' gestation for cervical and vaginal fetal fibronectin. A positive test was defined as a level of at least 50 ng/mL. The relation between a positive test and bacterial vaginosis at 23-24 weeks and clinical or histologic chorioamnionitis at delivery plus neonatal sepsis was determined. Fetal fibronectin was present in 4.0% of cervical and/or vaginal samples at 23-24 weeks and was nearly twice as common in women with bacterial vaginosis. Adjusting for the presence of bacterial vaginosis, race, and parity, women positive for fetal fibronectin were much more likely to have clinical chorioamnionitis (mean +/- standard deviation gestational age 30.6 +/- 4.1 weeks), with an odds ratio of 16.4 and 95% confidence interval of 7.1-37.8, and neonatal sepsis (6.3 and 2.0-20.0, respectively), than those who were fetal fibronectin-negative. A positive cervical fetal fibronectin test was a better predictor of clinical chorioamnionitis and neonatal sepsis than was a vaginal test or a combination of vaginal and cervical tests. Among 40 women who delivered before 32 weeks and had placental histology available for evaluation, ten had a positive cervical and/or vaginal fetal fibronectin test before delivery; all ten had histologic evidence of chorioamnionitis, compared with only 13 of 30 women (43%) who were fetal fibronectin-negative (P = .02). Women with bacterial vaginosis were more likely to have a positive fetal fibronectin test than uninfected women. Women with a positive fetal fibronectin test who delivered before 32 weeks' gestation all had evidence of histologic chorioamnionitis. Women positive for fetal fibronectin also had a 16-fold increase in clinical chorioamnionitis and a sixfold increase in neonatal sepsis. There is strong evidence that upper genital tract infection and cervical and/or vaginal fetal fibronectin are closely linked.

The preterm prediction study: Fetal fibronectin, bacterial vaginosis, and peripartum infection

Objective To determine the relation between vaginal and upper genital tract infection and cervical-vaginal fetal fibronectin levels. Methods We screened 2899 women at ten centers every 2 weeks from 23–24 to 30 weeks' gestation for cervical and vaginal fetal fibronectin. A positive test was defined as a level of at least 50 ng/mL. The relation between a positive test and bacterial vaginosis at 23–24 weeks and clinical or histologic chorioamnionitis at delivery plus neonatal sepsis was determined. Results Fetal fibronectin was present in 4.0% of cervical and/or vaginal samples at 23–24 weeks and was nearly twice as common in women with bacterial vaginosis. Adjusting for the presence of bacterial vaginosis, race, and parity, women positive for fetal fibronectin were much more likely to have clinical chorioamnionitis (mean ± standard deviation gestational age 30.6 ± 4.1 weeks), with an odds ratio of 16.4 and 95% confidence interval of 7.1–37.8, and neonatal sepsis (6.3 and 2.0–20.0, respectively), than those who were fetal fibronectin-negative. A positive cervical fetal fibronectin test was a better predictor of clinical chorioamnionitis and neonatal sepsis than was a vaginal test or a combination of vaginal and cervical tests. Among 40 women who delivered before 32 weeks and had placental histology available for evaluation, ten had a positive cervical and/or vaginal fetal fibronectin test before delivery; all ten had histologic evidence of chorioamnionitis, compared with only 13 of 30 women (43%) who were fetal fibronectin-negative ( P = .02). Conclusion Women with bacterial vaginosis were more likely to have a positive fetal fibronectin test than uninfected women. Women with a positive fetal fibronectin test who delivered before 32 weeks' gestation all had evidence of histologic chorioamnionitis. Women positive for fetal fibronectin also had a 16-fold increase in clinical chorioamnionitis and a sixfold increase in neonatal sepsis. There is strong evidence that upper genital tract infection and cervical and/or vaginal fetal fibronectin are closely linked.

Fetal fibronectin, interleukin-6, and C-reactive protein are useful in establishing prognostic subcategories of idiopathic preterm labor

OBJECTIVE: Our purpose was to evaluate fetal fibronectin, interleukin-6, and C-reactive protein from patients with preterm labor to establish prognostic subcategories. STUDY DESIGN: Thirty-seven patients with preterm labor had cervical fetal fibronectin and plasma C-reactive protein sampled. Eighteen of these patients had amniotic fluid interleukin-6 levels measured. Outcome variables were (1) delivery before 34 week and (2) delivery within 48 hours. RESULTS: Detectable cervical fetal fibronectin identified 89% of patients who were delivered before 34 weeks' gestation. Interleukin-6 >1500 pg/ml identified 88% of patients who were delivered within 48 hours. C-reactive protein >1.5 mg/dl correlated with elevated interleukin-6 levels ( p < 0.001). CONCLUSIONS: Three subcategories of idiopathic preterm labor were evident: (1) fetal fibronectin nondetectable (37% likely to be delivered before 34 weeks), (2) fetal fibronectin detectable but interleukin-6 <1500 pg/ml (79% likely to be delivered before 34 weeks but 85% with >48 hours' latency), and (3) fetal fibronectin present and interleukin-6 >1500 pg/ml (91% likely to be delivered with <48 hours' latency).

Cervical fetal fibronectin correlates to cervical ripening.

It is well established that the cervical ripeness is of great prognostic value at labor induction. The available methods of measuring the cervical ripeness are not satisfactory. This study was therefore initiated to investigate if there is any correlation between cervical fetal fibronectin and cervical ripening at term. Three groups were included in this study: women with unripe cervices, women with spontaneous cervical ripening and those with PGE2-induced cervical ripening. Fetal fibronectin was measured by ELIZA after sampling from the cervical canal. The cervical fetal fibronectin was low in women with unripe cervices. In women with favorable cervices a ten fold higher level was found. The fibronectin level was even higher after PGE2-induced ripening. Conclusively an increased amount of cervical fetal fibronectin is registered during the cervical ripening process. A level of > 0.80 microgram/ml of cervical fetal fibronectin seems to indicate a favorable cervix.

Fetal fibronectin detection for prediction of preterm birth in low risk women.

To evaluate the clinical value of cervical fetal fibronectin detection by a quantitative enzyme-linked immunosorbent assay (ELISA) (PTDcheck, Adeza Biomedical, Sunnyvale, California, USA) as a screening tool for the prediction of preterm contractions and preterm delivery in an unselected population of pregnant women globally considered to be at low risk for preterm delivery (n = 133). A prospective study in which cervical fetal fibronectin samples were collected at two-week intervals between 26 and 36 weeks of gestation. A regional training hospital. One hundred and thirty-three singleton pregnancies presenting consecutively at an antenatal clinic. Occurrence of preterm contractions and preterm delivery (delivery at < 37 weeks of gestation). Twenty-four (18%) patients were considered positive for the presence of fetal fibronectin. Overall 15 patients (11%) developed preterm contractions and, despite therapeutic intervention, 10 patients (8%) were delivered preterm. As a predictor for preterm contractions, cervical fetal fibronectin detection had a sensitivity of 47%, a specificity of 86%, a positive predictive value of 29% and a negative predictive value of 93%. As a predictor for preterm delivery, cervical fetal fibronectin detection had a sensitivity of 60%, a specificity of 85% a positive predictive value of 25% and a negative predictive value of 96%. Cervical fetal fibronectin determinations at a two-week sampling frequency for prediction of preterm birth in a general obstetric population at low risk for preterm birth has limited clinical value as a routinely performed screening procedure.

The presence of cervical and vaginal fetal fibronectin predicts preterm delivery in an inner-city obstetric population

It has previously been shown that fibronectin bearing a specific oncofetal domain is present at the chorionic-decidual interface and that its release into cervical and vaginal secretions accurately predicts preterm delivery in patients with uterine contractions. This study examines whether serial assessment of cervical and vaginal fetal fibronectin allows for the prediction of preterm delivery in symptom-free patients derived from an inner-city, general obstetric population. Cervical and vaginal samples were obtained from 429 consenting patients who received routine prenatal care between 24 and 37 weeks' gestation. A sensitive immunoassay was used to quantitate cervical and vaginal fetal fibronectin levels, and clinicians were blinded to fetal fibronectin results. Post hoc receiver operating characteristic curve analysis was used to determine which sample site (cervical or vaginal), fetal fibronectin concentration, and number of consecutive positive samples optimized screening efficacy. Logistic regression was employed to determine whether fetal fibronectin was an independent predictor of preterm delivery. The spontaneous preterm delivery rate was 11% (49/429). Among the 326 patients sampled within 28 days of delivery, receiver operating characteristic curve analysis indicated that the presence of a single cervical fetal fibronectin value > 60 ng/ml between 24 and 36 weeks' gestation predicted preterm delivery with a sensitivity of 73%, a specificity of 72%, and positive and negative predictive values of 25% and 95%, respectively. A vaginal fetal fibronectin value > 50 ng/ml predicted preterm delivery with a sensitivity of 68%, a specificity of 80%, and positive and negative predictive values of 30% and 95%, respectively. Cervical and vaginal fetal fibronectin predicted preterm deliveries resulting from both membrane rupture and preterm labor with intact membranes. A positive fetal fibronectin result preceded preterm delivery by 3.4 (+/- 3.2) weeks. Stepwise logistic regression demonstrated that cervical and vaginal fetal fibronectin levels were independent predictors of preterm delivery with adjusted odds ratios of 8.9 (95% confidence interval 3.6 to 22.1) and 6.0 (95% confidence interval 2.6 to 13.7), respectively. Among patients undergoing monthly cervical and vaginal sampling between 24 and 36 weeks' gestation, the presence of fetal fibronectin is a sensitive and specific predictor of preterm delivery.