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Abstract Spontaneous preterm birth before 37 weeks’ gestation occurs in 7-11% of pregnancies and before 34 weeks in 3-7% of pregnancies .The latter is more likely to be due to pathological than physiological causes. Preterm delivery, particularly before 34 weeks of gestation, accounts for three-quarters of neonatal mortality and one-half of long-term neurological impairment in children. Risk prediction for preterm birth both for screening and diagnosis is based on a combination of patients’ characteristics, symptoms, physical signs and investigations. Risk scoring, maternal anthropometry, ultrasound measurement of cervical length, cervicovaginal fetal fibronectin (fFN), and testing for bacterial vaginosis infection (BV), have been evaluated for their utility in predicting preterm birth. The studies on these tests generally used preterm birth before 36 weeks’ gestation as the outcome. Only cevicovaginal fFN and cervical length were also considered for birth before 34 weeks’ gestation. Fetal fibronectin is found in high concentrations in the amniotic fluid and in the i Its function during pregnancy is likely the maintenance of the choriodecidual extracellular matrix. It acts as the glue that attaches the fetal membranes to the underlying uterine deciduas. It may also play a role in placental cleavage following delivery nterface between the deciduas and the trophoplast cells. The fFN is often found in the cervicovaginal secretion before 16-18 weeks of gestation, and again at the end of normal pregnancy as labor approaches. 146 The aim of this work is to assess the cervicovaginal fetal fibronectin (fFN) level in the gestational age between 22-26weeks in women with cervical cerclage as a predictive method for preterm delivery before 36 weeks. This study was carried out at Ain Shams University Maternity Hospital during the period from November 2010 to September 2012. Women approached in this study are those in antenatal out patient’s clinic and those admitted to the antepartum inpatient high risk service. The study is a prospective cohort study; the calculation of sample size was performed by MedCalc® version 7.4 computer software. It was found that at least 98 patients with cervical cerclage are needed at the start of the study to detect a difference of at least 30% in the incidence of preterm delivery with significance level of 0.05 and power of 0.8. Fetal fibronectin testing was done for all women with cervical cerclage at gestational age between 22 to 26 weeks then the women are divided into two groups; group (1) which included approximately 49 women with cerclage and fFN negative, group (2) which included approximately 49 women with cerclage and fFN positive. The test will be done during the regular antenatal examination via taking a sample of the vaginal discharge with a sterile plastic pipette under complete aseptic conditions. Follow up for patients will be done via taking another appointment for their next visit to the antenatal care clinic till the time of delivery, and by telephone number to be informed about of time of current delivery. The participating women were subjected to sterile speculum examination for collection of cervico-vaginal sample for fetal fibronectin assay. 147 Radial immunodiffusion (RID) was used for the purpose of fibronectin assay in this study. The method involved antigen diffusing radially from the cylindrical well through an agarose gel containing an appropriate mono-specific antibody. Demographic variables assessed at the study for each group were maternal age, gestational age at sampling, parity, number of previous cerclage, number of previous abortions, number of preterm labor, number of term labor and gestational age at current delivery. Maternal age at sampling, gestational age at sampling, parity, number of previous cerclage, number of previous abortion, number of previous preterm delivery and number of previous term delivery all showed no significant difference between the two groups with p˃0.05, but the only demographic variable that showed an evident significant difference between the two groups with p˂0.001 is the gestational age at current delivery which is considered preterm when occurred before 36 weeks of gestation as based on the current study. The diagnostic power of fFN in prediction of preterm labor (95% confidence interval) showing that its specificity is 64.0% (54.3-72.6%) , sensitivity is 64.6% (54.5-73.5%), with negative predictive value of 65.3%, positive predictive value of 63.3% and with efficacy of 64.3%. The results of the study revealed that they were 34.7% of women with fFN negative were delivered at gestational age less than 36 weeks, and they were 65.3% of them were delivered full term. While they were 63.3% of women with fFN positive were delivered prior to 36 weeks of gestation and 36.7% of them are delivered full term. |