Blind vaginal fetal fibronectin swab for prediction of preterm birth

Abstract

Aim: To assess the accuracy of blind vaginal swab in diagnosis of preterm labor (PTL) and prediction of subsequent occurrence of preterm birth (PTB). Methods: Eligible women who presented at 24-34 weeks of gestation with threatened PTL had their cervicovaginal secretions sequentially sampled for fetal fibronectin (fFN) using two types of swabbing techniques. The first swab was a blind vaginal swab collected without the aid of speculum, while the second one was a routine cervicovaginal swab. All participants were followed up until delivery. Results: fFN in both swabs was significantly higher in women who delivered before term compared with women who delivered at term. On regression analysis, r 2 = 0.735 and 0.785 for blind vaginal and cervicovaginal swabs respectively, while on receiver operating characteristic analysis the area under curve was 0.965 and 0.977, respectively, without a statistically significant difference. Using an fFN cut-off of ≥0.05 μg/dL, the sensitivity, specificity, positive predictive value and negative predictive value of blind vaginal swab to predict PTB were 53.9%, 91.9%, 70.0% and 85.0%, respectively; while those for cervicovaginal swab were 58.3%, 94.7%, 77.8% and 87.8%, respectively. Conclusions: In women presenting at 24-34 weeks of gestation with threatened PTL, blind vaginal fFN swab is as effective as cervicovaginal swab to predict PTB, but it is easier to perform and does not require doctor supervision.

Fetal Fibronectin as a Predictor of Preterm Delivery: A Nigerian Cohort Study

“…The negative predictive value of the fetal fibronectin test in symptomatic women in this study which is 87.76% agrees with the value of 85.0% reported by Farag et al [ 13 ]. This means that most women who tested fetal fibronectin negative tend not to deliver preterm babies.…”

“…Fetal fibronectin is a major component of the extracellular matrix of the membranes of the amniotic sac confines at the choriodecidual junction [ 12 ]. Fetal fibronectin can be distinguished from its other family members by the presence of a unique region known as the III-CS domain [ 13 ]. Scientists have developed a monoclonal antibody called FDC-6 which specifically recognizes the III-CS domain of fetal fibronectin.…”

“…In 1991, Lockwood et al demonstrated fetal fibronectin to be an effective predictor of preterm labour in pregnant women with intact membranes and preterm birth [ 10 ]. Fetal fibronectin is elevated in cervicovaginal secretion during the first 24 weeks of pregnancy but diminishes between 24 and 34 weeks in normal pregnancies [ 13 ]. Detection of fetal fibronectin in cervicovaginal secretions between 24 and 34 completed weeks gestation is reported to be associated with preterm delivery in symptomatic and asymptomatic pregnant women [ 14 ].…”

Serum ferritin level as a marker of preterm labor

“…Various biochemical markers have been developed to predict preterm labour. These markers include foetal fibronectin in the cervicovaginal secretions [9] , human chorionic gonadotropin in the cervicovaginal secretions [10] , maternal serum corticotropinreleasing hormone (CRH) [11] , maternal serum alpha-fetoprotein (AFP) at 11-13 weeks. [12] This might be explained by the status of an acute phase reaction to subclinical infections that are commonly associated with preterm labour.…”

Comparison of serum ferritin levels in pregnant women with preterm and term deliveries

“…such as cervical length measurement through transvaginal ultrasound, bacterial vaginosis tests, fetal fibronectin, hCG in cervical and vaginal secretions (5,6), maternal corticotropin releasing hormone (CRH) (7), and maternal serum alpha fetoprotein in 11-13 weeks (8), have been suggested to predict preterm delivery; however none of them are able to accurately identify cases at risk for preterm delivery and its related complications (9,10). Acute phase response is defined as the systemic response to inflammation and tissue damage that occurs within hours to days (11).…”