How you prepare

You don't need to do anything special to prepare for the fetal fibronectin test.

Other precautions

To avoid a false-positive result, the test will be done before any pelvic exam or vaginal ultrasound. Avoid having sex for 24 hours before the test. Also, avoid using douches, lotions and soaps, which can affect test results, for at least a day before the test.

Vaginal bleeding can affect the test results, too. If you experience vaginal bleeding, the test probably won't be done.

If the amniotic sac ruptures — your water breaks — the test won't be done. The amniotic sac is a fluid-filled membrane that cushions your baby in the uterus.

April 21, 2016
References
  1. Lockwood CJ. Diagnosis of preterm labor and overview of preterm birth. http://www.uptodate.com/home. Accessed Feb. 21, 2016.
  2. Fetal fibronectin. Lab Tests Online. https://labtestsonline.org/understanding/analytes/ffn/tab/sample/. 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.