Results of the fetal fibronectin test are either positive or negative:

  • Positive. A positive result means that fetal fibronectin is present in your cervical fluid. If you have a positive result between weeks 22 and 34, you're at increased risk of preterm labor.

    Your health care provider might take steps to prepare for a potentially early birth, such as giving you steroids to speed your baby's lung maturity. Or, you might be given medications to decrease the risk of neurological complications, such as cerebral palsy, in your infant. If you're having contractions, you might be given drugs to decrease them.

  • Negative. A negative result means that fetal fibronectin isn't present in your cervical fluid. This indicates that you aren't likely to deliver in the next two weeks. In fact, a negative result might be the most powerful benefit of the test — allowing you and your health care provider to relax a bit with the knowledge that a premature birth isn't imminent.

Whether your test results are positive or negative, remember that prompt recognition of preterm labor might give your health care provider a chance to delay premature birth or improve your baby's readiness for birth.

If you're concerned that you might be going into labor early, contact your health care provider. Don't worry about mistaking false labor for the real thing.

Warning signs of preterm labor include:

  • Regular or frequent contractions — a tightening sensation in the abdomen
  • Constant low, dull backache
  • A sensation of pelvic or lower abdominal pressure
  • Mild abdominal cramps
  • Vaginal spotting or bleeding
  • Watery vaginal discharge (water breaking) — in a gush or a trickle
  • A change in vaginal discharge
April 21, 2016
  1. Lockwood CJ. Diagnosis of preterm labor and overview of preterm birth. Accessed Feb. 21, 2016.
  2. Fetal fibronectin. Lab Tests Online. Accessed Feb. 20, 2016.
  3. DeFranco EA, et al. Improving the screening accuracy for preterm labor: Is the combination of fetal fibronectin and cervical length in symptomatic patients a useful predictor of preterm birth? A systematic review. American Journal of Obstetetrics and Gynecology. 2013;208:233.
  4. Van Baaren GJ, et al. Risk factors for preterm delivery: Do they add to fetal fibronectin testing and cervical length measurement in the prediction of preterm delivery in symptomatic women? European Journal of Obstetrics & Gynecology and Reproductive Biology. 2015;192:79.
  5. McLaren JS, et al. Prediction of spontaneous preterm birth using quantitative fetal fibronectin after recent sexual intercourse. American Journal of Obstetetrics and Gynecology. 2015;212:89.
  6. Wick MJ (expert opinion). Mayo Clinic, Rochester, Minn. March 23, 2016.