Fetal Fibronectin (FFN) is a protein that acts as a biological glue, attaching the fetal sac to the uterus lining during pregnancy. The presence of this protein in cervical or vaginal discharge can be an indicator of preterm labor, as it can suggest that the fetal sac is separating from the uterus. An FFN test is frequently used to evaluate the risk of premature birth in pregnant women showing symptoms of labor.

Key Takeaways

  1. Fetal fibronectin (FFN) is a type of protein that is produced during pregnancy, acting as a form of glue to secure the amniotic sac to the lining of the uterus. High levels of FFN might be a sign of an upcoming preterm birth.
  2. The FFN test is used for women with symptoms of preterm labor to establish the likelihood of delivery within a short timeframe. A negative FFN result is highly predictive of a patient not delivering within the next week, offering reassurance to both physician and patient.
  3. The FFN test is a valuable tool in the management of pregnancies with threatened preterm labor, saving healthcare resources by reducing unnecessary hospital admissions and treatments.


Fetal Fibronectin (FFN) is significant in the realm of motherhood mainly because it serves as a potential predictive marker for preterm labor. It is a protein that functions like a biological glue, attaching the amniotic sac to the lining of the woman’s uterus.

An FFN test is typically performed between the 22nd and 35th weeks of pregnancy in women showing symptoms of preterm labor. The presence of FFN during this period may indicate an increased risk of preterm birth, thereby alerting healthcare professionals to take necessary steps to manage the situation and increase the chances of a healthy and full-term pregnancy.

Conversely, a negative test often provides reassurance that the risk of delivering within the next two weeks is extremely low. Thus, FFN plays a crucial role in predicting, managing, and potentially preventing preterm labor.


Fetal Fibronectin (fFN) is primarily used as a biomarker to assess the risk of preterm birth. It is recognized as a type of “biological glue” that assists in binding the chorion, a part of the fetus’s placenta, to the uterine lining.

As the term progresses, Fetal Fibronectin is typically discharged and reabsorbed. Hence, a significant amount of Fetal Fibronectin detected in cervical or vaginal discharge can indicate a higher likelihood of preterm labor, helping healthcare professionals to take necessary prevention steps.

Doctors usually administer a fFN test to pregnant women who show symptoms of preterm labor, like regular contractions or changes in cervical consistency, especially between the 22nd and 34th weeks of pregnancy. The absence of Fetal Fibronectin is indicative of a significantly decreased probability of delivering in the next two weeks, providing reassurance to both the pregnant woman and her healthcare team.

Conversely, if the fFN test has a positive outcome, it suggests a relatively higher likelihood of preterm birth, warranting closer monitoring and potentially, medical intervention.

Examples of Fetal fibronectin (FFN)

Example 1: Lucy is a pregnant woman who is in her 24th week of pregnancy. She begins to feel some unusual contractions and visits the hospital. The doctor decides to run a Fetal fibronectin (FFN) test to check if she is at risk of preterm labor. A positive FFN test result would indicate the presence of the fibronectin protein, which often means that her body is preparing for delivery too early. This could help her medical team take necessary actions to prevent preterm birth.

Example 2: Sarah is a mother who has a history of preterm births. She’s now pregnant again and her doctor schedules regular FFN tests for her as part of her prenatal care. These tests are used as a preventive measure to ensure that if she starts secreting the fetal fibronectin protein, her doctor can institute measures to help prolong her pregnancy.

Example 3: Rebecca is pregnant with twins and this increases her risk for preterm labor. During her routine check-up in the 22nd week, her obstetrician decides to run a FFN test to determine her likelihood of going into early labor. Fortunately, the results come back negative, indicating a low probability of preterm birth in the near future. This gives Rebecca peace of mind and allows her doctor to monitor her situation effectively.

Frequently Asked Questions about Fetal Fibronectin (FFN)

What is Fetal Fibronectin (FFN)?

Fetal fibronectin (FFN) is a protein that is produced during pregnancy and functions as a biological glue, attaching the amniotic sac to the lining of the uterus. FFN is not typically present in vaginal secretions from the middle of pregnancy until close to the time of delivery, unless the body is preparing for labor.

Why is Fetal Fibronectin (FFN) testing done?

FFN testing is typically done to assess the risk of preterm labor. If there is no FFN detected in vaginal secretions between 24 to 34 weeks of pregnancy, the risk of delivering within the next two weeks is extremely low. However, if FFN is detected, there is a higher risk of preterm labor, but not all women with detectable levels of FFN will deliver early.

How is a Fetal Fibronectin (FFN) test done?

A FFN test is a simple, non-invasive swab test that is similar to a Pap smear. A healthcare provider will gently swab the cervix and vagina to collect a sample which will then be tested in a laboratory for the presence of FFN.

Are there any risks to the Fetal Fibronectin (FFN) test?

The FFN test is generally safe and poses no known risks to the mother or baby. As it’s a non-invasive test, there is minimal discomfort associated with the procedure.

What should I do if my FFN test results are positive?

A positive FFN test means that there is a higher risk of preterm labor. However, it does not guarantee that you will deliver early. It’s important to discuss your results with your healthcare provider. They will guide you on the next steps and necessary precautions you should take to manage the risk of preterm labor.

Related Motherhood Terms

  • Premature Labor
  • High-risk Pregnancy
  • Maternal-fetal Medicine
  • Cervical Length Measurement
  • Preterm Birth Prediction

Sources for More Information

  • WebMD: A leading health information website providing detailed guides, articles, and expert opinions on multiple health topics including Fetal Fibronectin.
  • Mayo Clinic: A reputable resource for numerous health-related topics offering informative content about the subject matter.
  • American Pregnancy Association: A national health organization committed to promoting pregnancy wellness that would have reliable articles on Fetal Fibronectin.
  • MedlinePlus: A service of the U.S. National Library of Medicine that provides comprehensive information about diseases, health conditions, and wellness issues, including details on Fetal Fibronectin.