Fetal fibronectin measurement
What is this test?
This test measures the levels of a protein called fetal fibronectin in cervicovaginal secretions. It is used to help assess the risk of preterm birth. It is also used to predict successful induction of labor in pregnancy.
Why do I need this test?
Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:
- Onset of labor induced
- Premature labor
When and how often should I have this test?
When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.
Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.
The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.
How should I get ready for the test?
You may be asked to sign a consent form prior to this procedure. Review the consent form with the healthcare worker, and ask any questions that you have before signing the consent form. Tell the healthcare worker if you have a medical condition or are using a medication or supplement that causes excessive bleeding. Do not have sexual intercourse for 24 hours before the procedure.
You may be asked to urinate prior to collection of cervicovaginal secretions. This may make it easier for the healthcare worker to collect the sample, and may make the procedure more comfortable for you.
How is the test done?
To collect a sample of cervicovaginal secretions, you may be asked to lie on your back with your legs spread and feet placed in stirrups. A healthcare worker will use a swab to collect secretions from an area inside the vagina. The secretions are then sent for testing.
How will the test feel?
The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.
What should I do after the test?
Ask your healthcare worker if there are special instructions for you to follow after this test.
What are the risks?
Ask the healthcare worker to explain the risks of this test or procedure to you before it is performed.
What are normal results for this test?
Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following is considered to be a normal result for this test:
- Pregnancy: ≤50 nanograms/mL 
What might affect my test results?
- Recent sexual intercourse 
- Preeclampsia 
- Recent cervical examination 
- Vaginal bleeding 
- Disinfectant use 
What follow up should I do after this test?
Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.
Where can I get more information?
- March of Dimes Birth Defects Foundation - http://www.marchofdimes.com
 Tekesin I, Marek S, Hellmeyer L, et al: Assessment of rapid fetal fibronectin in predicting preterm delivery. Obstet Gynecol 2005; 105(2):280-284.
 ACOG: American College of Obstetrics and Gynecology: Management of preterm labor. ACOG Practice Bulletin No 43. Obstet Gynecol 2003; 101:1039-1047.
 Leitich H & Kaider A: Fetal fibronectin--how useful is it in the prediction of preterm birth. BJOG 2003; 110 Suppl 20:66-70.
 Honest H, Bachmann LM, Gupta JK, et al: Accuracy of cervicovaginal fetal fibronectin test in predicting risk of spontaneous preterm birth: systematic review.. BMJ 2002; 325:301.
 Leitich H, Egarter C, Kaider A, et al: Obstetrics. American Journal of Obstetrics and Gynecology 1999; 180(5):1169-1176.
 Garite TJ, Casal D, Garcia-Alonso A, et al: Fetal fibronectin: a new tool for the prediction of successful induction of labor. Am J Obstet. Gynecol. 1996; 175(6):1516-1521.
 Eriksen NL, Parisi VM, Daoust S, et al: Fetal fibronectin: a method for detecting the presence of amniotic fluid. Obstet Gynecol 1992; 80(3 Pt 1):451-454.
 Lukes AS, Thorp JM Jr, Eucker B, et al: Predictors of positivity for fetal fibronectin in patients with symptoms of preterm labor.. Am J Obstet Gynecol 1997; 176:639-641.
 Wu AHB: Tietz Clinical Guide to Laboratory Tests, 4th ed. WB Saunders, St. Louis, MO, 2006, pp -.
 Yeast JD & Lu G: Biochemical markers for the prediction of preterm delivery. Clin Perinatol 2007; 34(4):573-86, vi.
Last Updated: 7/4/2018