How you prepare

By Mayo Clinic Staff

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

To avoid a false-positive result, the test will be done before any pelvic exam or vaginal ultrasound. It's also best to avoid having sex for 24 hours before the test.

Vaginal bleeding can affect the test results. If you experience vaginal bleeding, the fetal fibronectin test will likely be postponed.

If the amniotic sac ruptures — your water breaks — the test will be canceled. The amniotic sac is a fluid-filled membrane that cushions your baby in the uterus. If the sac is no longer intact, labor and delivery are inevitable — even if your baby isn't full term.

May 10, 2013