Fetal fibronectin is a protein that’s believed to help keep the amniotic sac “glued” to the lining of the uterus. The amniotic sac is the fluid-filled membrane that cushions your baby in the uterus.
Fetal fibronectin is often present in vaginal discharge before week 22 of pregnancy. Fetal fibronectin also begins to break down and can be detected in vaginal discharge toward the end of pregnancy.
- 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.
Note that false-positive result may occur. Doctors will follow up with other exams when the test result shows positive.
- 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.