Cervical fetal fibronectin as a predictor of first trimestre pregnancy outcome in unexplained recurrent miscarriage.

OBJECTIVE: To determine whether cervical fetal fibronectin is a reliable predictor of first trimester pregnancy outcome in patients with unexplained recurrent miscarriage. STUDY DESIGN: A prospective observational study was carried out on 49 pregnant women with a history of unexplained recurrent miscarriage. In all participants the presence of fetal fibronectin in the cervical secretion was determined with a qualitative rapid immunoassay. The outcome of the first trimester pregnancy was recorded a successful outcome was a pregnancy that progressed beyond 12 weeks of gestation; a miscarriage referred to a pregnancy loss in the first 12 weeks. RESULTS: Of the 49 subjects screened, fetal fibronectin was positive in 17 and negative in 32. Overall, 14 pregnancies resulted in fetal loss before the 12th week of gestation. Fetal cervical fibronectin was positive in 6 of the 14 patients who miscarried and in 11 of the 35 in whom outcome was successful. As predictor of first trimester pregnancy outcome the test had a sensitivity and a specificity of 43% and 69% and positive and negative predictive values of 35%, and 75%, respectively. Subgroup analysis by number of previous miscarriages and maternal age gave similar values. CONCLUSION: This study examines the possible value of cervical fetal fibronectin in predicting first trimester pregnancy outcome. We conclude that the occurrence of positive or negative fetal cervical fibronectin test has only limited predictive value and therefore its use cannot be considered for clinical application.