Fetal Fibronectin In Cervicovaginal Secretions As A Predictor Of Term Labor And The Mechanism Involving In Initiation Of Human Parturition

[Background] With the development of perinatal medicine, elective inductions are becoming more acceptable and account for approximately 10% of all deliveries. However, blind induction of labor results in an increase in cesarean delivery and greatly increased the family, social economic burden .The key to successful induction is cervical ripening. At present, the cervical Bishop score is a commonly used method to predict vaginal delivery in women undergoing induction of labor. But ,Only women who have induction of labor with a score of more than eight have a similar rate of vaginal delivery as those women who enter spontaneous labor.And if cervical score is less than five, predictive power is poor. Especially in nulliparous women ,unfavourable cervices are more common and therefore the ability of Bishop score predict vaginal delivery is limited.Fetal fibronectin (FFN) is an extracellular matrix glycoprotein, found in high concentrations in the maternal-fetal interface and amniotic fluid, normally present in cervicovaginal secretions up to 20 weeks of gestation. After 22 weeks of gestation,It is not normally found in appreciable amounts in cervicovaginal secretions.When the date of onset of labor is imminent, fetalfibronectin enters into cervical and vaginal secretions again, The ability of fetal fibronectin to predict preterm labor has been extensively evaluated. And researches results showed that fetal fibronctin is a reliable method of biochemical technique applied for indication of preterm labor. But study about application of fetal fibronectin in indication of induced labor for term is inadequate and controversial.[Objective]Our purpose was to determine whether the presence of fetal fibronectin in cervicovaginal secretions of patients reflected the cervical state and to investigate the application value of fetal fibronectin qualitative test in predictive of successful induction of labour and mode of delivery at term.[Methods] The study enrolled prospectively 37women undergoing labor induction at term. All cases studied were singleton pregnancies with cephalic presentations and primary parturition. Patients were exlcuded if they had ruptured membranes or uterine contraction, cephalopelvic disproportion,a digital examination and intercourse history in 72 hours and serious pregnant complication.For qualitative detection of fetal fibronectin in cervicovaginal secretions,a fast-reacting membrane immunoassay was used, with the positive cutoff value set at 50 ng/ml.This fetal fibronectin membrane immunoassay is a solid-phase immunogold assay which is produced by the U.S.Adeza Biomedical Corp and HOB Biotech Group Co. Ltd to provide.Fetal fibronectin was first assayed with cervicovaginal secretions on the day before induction of labor. Then the cervix was assessed by digital examination and scored with a modified Bishop's score. All fetal fibronectin test and Bishop score evaluations were performed by the appointed obstetricians and the results were blinded to clinicians. Induction of labor was performed with propess.The study population was divided into two groups according to the fibronectin test: positive group consisted of women whose cervical secretions were positive for fetal fibronectin and negative group consisted of women with negative test results. Bishop's score,the interval between the sampling and the time of delivery and the mode of delivery. [Results]1. Of 37 women,25 cases were tested positive and 12 were tested negative for fetal fibronectin. The Bishop score in positive group was significantly higher than negative group,Fetal fibronectin can reflect the cervical maturity.2. Patients with a positive fetal fibronectin, the success of preinduction cervical ripening was 88% and the success of inductiforon of labor of was 80% and the success of vinginal delivery was 68%,while for the 12 cases with negative fetal fibronectin, the success of inductiforon of labor of was 33.33% and the success of vinginal delivery was 25% (P<0.05).3. The sensitivity,specificity,positive predictive value,negative predictive value of fetal fibronectin for success of inductiforon of labor was 83.3% , 61.54 % , 80% , 66.7%. The results were better than that of Bishop score.[Conclusions] Fetal fibronectin is a good marker for cervical maturity. It is more accurate and objective than Bishop score.Qualitative test of fetal fibronectin in cervicovaginal can be used to predict accurately the outcome of induced labor at term. If application of FFN detection in the cervix secretion combined cervical Bishop score in predicting induction of labor, It much increase successful vaginal deliver rates.Further research with larger samples will contribute to select right opportunity for induction of term labor, and reduce the rate of cesarean section.Partâ…¡The expression of fetal fibronectin(FFN),matrix metalloproteinase-9 (MMP-9) in human placenta and fetal membrane at parturition[Backgroud] Fetal fibronectin, a major adhesive molecule secreted by the trophoblast, is thought to play a critical role as a trophoblastic"glue"in the formation of this uteroplacental junction.In embryo implantation and placentation , FFN interacts with its receptor, that may bring change of proteolytic enzyme activity level, and it is important that FFN involves in maintaining structural integrity of the implantation and chorion site and retaining the stability of maternal-fetal interface throughout pregnancy.In the third trimester, when FFN in cervicovaginal secretion is positive, the time of onset of labor is coming, but it`s rare study about the reason and mechanism how FFN involving in the onset of labor.[Objective]To examine the the mRNA expression of FFN and MMP-9 in human placentaand fetal membrane and to explore their correlations at the onset of labor.[Methods] Real-time quantitative polymerase chain reaction was used to measure the expressions levels of FFN mRNA and MMP-9 mRNA in placenta and fetal membrane of both in no-labor ( cesarean section group ) and labor group(vaginal delivery group).[Results] In labor group the expression of FFN mRNA in human placenta was higher than that in no-labor, but was similar in fetal menbrane. In labor group both in human placenta and in fetal membrane the MMP-9 mRNA were significantly higher than that in no-labor.[Conclusions] The difference expression of FFN and MMP9 mRNA in the placenta tissues and fetal menbrance may play an important role in the onset of labor.