The Clinical Significance of the Detecion of Fetal Fibronectin in the Cervicovaginal Secretions of Woman before Labor Induction

Ahn, S B; Kong, K H; Lee, H G; Kim, J B; Choi, S Y; Choi, Y S; Lee, Y; Kim, C Y; Kim, S P

Abstract

OBJECTIVE
Our purpose was to determine whether the detection of fetal fibronectin in cervicovaginal secretions of woman before labor induction reflected readiness of the uterus and ultimately the ease of induction of labor.
METHODS
We studied 52 women undergoing induction of labor by means of prostaglandin E2after 37 weeks` gestation. A Dacron polyester swab specimen was first taken from endocervix and posterior vaginal fornix for assessment of the presence of the fetal fibronectin. The cervix was then assessed by digital vaginal examination and scored with modified Bishop score. The cervicovaginal fetal fibronectin was measurde quantitatively by fetal fibronectin immunoassay (Adeza Biomedical, Sunnyvale, California, USA). The results were considered positive when specimens had a fetal fibronectin concentration above 50ng/ml. Induction of labor was considered to be successful if vaginal delivery occured within 24 hours after the application of the PGE2 tablets. We compared positive result for fetal fibronectin wtth high Bishop score (> or =5) as a predictor of successful labor.
RESULTS
9 samples were excluded due to blood contamination. Total 43 samples were studied. 21 had positive results for fetal fibronectin and 22 had negatibve results. 25 were delivered within 24 hours of the application of PGE2. Of the women inthis group, two were delivered by cesarean section. The results were as follows: 1. Women with fetal fibronectin-positive cervicovaginal secretions had a significantly shorter (10 hours 57 minutes vs 29 hours 01 minutes, P=0.0001) interval between prostaglandin application and delivery, and needed a significantly lower (1.1:2, P=0.007) numbers of PGE2tablets than did fetal fibronectin-negative patients. 2. Bishop`s score was not different in interval between prostaglandin application and delivery (group with high score 20 hours 09 minutes vs group with low score 16 hours 13 minutes, p = 0.5850), and numbers of PGE2tablets (1.5 vs 1.51, P=0.855). 3. Patients with fetal fibronectin-positive cervicovaginal secretions were more delivered within 24 hours than Patients with fibronectin - negative group (fetal fibronectin positive group: 19/21, 90.5% vs fetal fibronectin negative group: 6/22, 22.3%). 4. The rate of unsuccessful induction of labor and operative delivery was highest in women with fibronectin-negative cervicovaginal secretions and olw Bishop`s score (7/8,87.5%) 5. Multiple logistic regression shows that only the fetal fibronectin enzyme immunoassay provides an independent statistically significant predictor for purposes of predicting vaginal delivery within 24 hours (P=0.0025, adjusted odds ratio 25.33). 6. The positive value of cervicovaginal fetal fibronectin was more predictive of successful labor induction than Bishop score > or = 5 (sensitivity 82.6%: 17.4%, positive predictive value 95.0%: 57.1%).
CONCLUSIONS
Positive cervicovaginal fetal fibronectin before labor induction may be a useful biochemical predictor for successful induction of labor.