Fetal Fibronectin Testing (PDF)

fFN (fetal Fibronectin) testing

What is Fetal Fibronectin?

Fetal fibronectin is a glycoprotein found in amniotic fluid and placental tissue. It is normal to find fFN in vaginal secretions prior to 18 weeks of pregnancy and after 37 weeks. If fFN is detected in vaginal secretions between 22 and 37 weeks of pregnancy, there is an increased risk of preterm delivery (delivery before 37 weeks).

How does my provider screen for fFN?

Your provider will use a sterile swab that is placed in the vagina behind the cervix. The sample that is obtained from this swab is then analyzed by a laboratory to determine if fFN is present in the vaginal secretions. This test is most accurate if you refrain from sexual intercourse for 24 hours prior to the test being done.

Why would my provider screen me for fFN?

Your provider will only screen you if there are concerns you may be going into labor early. If you have uterine contractions, have felt leaking fluid, or have other signs of preterm labor, your provider may want to perform the fFN test.

How accurate are the results?

If the fFN test is negative, there is less than 1% chance that you will start labor within the two weeks following the test.
If the fFN test is positive, your provider may prescribe medications, changes in your activity level, or possibly hospitalization to help prevent preterm labor and delivery. Having a positive fFN test does not mean that you will have your baby early. It is a piece of information that helps to guide your provider to monitor your pregnancy closely.

Written by the Women’s Group Practitioners Last Reviewed in November 2009
© Copyright 2009 The Women’s Group PC 1