Fetal Fibronectin (Cervicovaginal Swab) Rapid test kits are intended to detect fetal fibronectin secretion in cervicovaginal environment.
Preterm delivery, defined by the American College of Obstetricians and Gynecologists as delivery prior to the 37th week of gestation, is responsible for the majority of non-chromosomal perinatal morbidity and mortality. Symptoms of threatened preterm delivery include uterine contractions, change of vaginal discharge,vaginal bleeding, backache, abdominal discomfort, pelvic pressure, and cramping. Diagnostic modalities for identification of threatened preterm delivery include uterine activity monitoring and performance of a digital cervical examination, which allows estimation of cervical dimensions. These methods have been shown to be limited, as minimal cervical dilatation (< 3 centimeters) and uterine activity occur normally and are not necessarily diagnostic of imminent preterm delivery. While several serum biochemical markers have been evaluated, none have been widely accepted for practical clinical use. Fetal fibronectin (fFN), an isoform of fibronectin, is a complex adhesive glycoprotein with a molecular weight of approximately 500,000 daltons. Matsuura and co-workers have described a monoclonal antibody called FDC-6, which specifically recognizes III-CS, the region defining the fetal isoform of fibronectin. Immunohistochemical studies of placentae have shown that fFN is confined to the extracellular matrix of the region defining the junction of the maternal and fetal units within the uterus. Fetal fibronectin can be detected in cervicovaginal secretions of women throughout pregnancy by use of a monoclonal antibodybased immunoassay. Fetal fibronectin is elevated in cervicovaginal secretions during early pregnancy but is diminished from 22 to 35 weeks in normal pregnancies. The significance of its presence in the vagina during the early weeks of pregnancy is not understood. However, it may simply reflect the normal growth of the extravillous trophoblast population and the placenta. Detection of fFN in cervicovaginal secretions between 22 weeks, 0 days and 34 weeks, 6 days gestation is reported to be associated with preterm delivery in symptomatic and between 22 weeks, 0 days and 30 weeks, 6 days in asymptomatic pregnant women.