Fetal Fibronectin (fFN)

Preterm birth refers to a disease characterized by the interruption of pregnancy after 28 to 37 gestational weeks. Preterm birth is the leading cause of death and disability in most non-hereditary perinatal infants. Symptoms of preterm birth include uterine contractions, changes in vaginal discharge, vaginal bleeding, back pain, abdominal discomfort, a squeezing sensation in the pelvis and cramps.

As an isoform of fibronectin, Fetal Fibronectin (fFN) is a complex glycoprotein with a molecular weight of about 500KD. For pregnant women with signs and symptoms of preterm birth, if fFN ≥ 50 ng/mL between 0 day of 24 weeks and 6 days of 34 weeks, the risk of preterm birth increases within 7 days or 14 days (from the date of specimen testing from cervical vaginal secretions). For pregnant women without signs and symptoms of preterm birth, if fFN is elevated between 0 day of 22 weeks and 6 days of 30 weeks, there will be an increased risk of preterm birth within 6 days of 34 weeks.