Fetal fibronectin

Section through a pregnant uterus in the third to fourth month

Fetal fibronectin (fFN) is an extracellular matrix glycoprotein produced by amniocytes and cytotrofoblast cells, which occurs between the chorion layer and the decidua, where it helps maintain the integrity of the connection between the fetal egg and the uterus. The determination of fetal fibronectin in a vaginal smear can be used to recognize the risk of premature birth.

In early pregnancy, fFN values ​​are elevated due to normal tissue growth.
Before the 22nd week of pregnancy high levels of fetal fibronectin are found in vaginal secretions, after that these levels decrease (below 50 ng/ml) and rise again before delivery.

From the group of women with a positive fibronectin test, ends up with a premature delivery around 25 %. With a negative test, premature delivery occurs in about 1 %.

Links

• Premature delivery
• Fibronectin

Recommended literature

• Accuracy of cervicovaginal fetal fibronectin test in predicting risk of spontaneous preterm birth: systematic review
• Fetal Fibronectin Tests