Fetal Fibronectin

Medically Reviewed by Traci C. Johnson, MD on June 09, 2023
2 min read

The fetal fibronectin test isn't necessary for all pregnant women. Your doctor may suggest it if you're at risk of going into labor early. You may be at higher risk because you're bleeding (not usually because of the actually bleeding but because preterm labor is suspected. It cannot be done if blood is present), have a health problem, have early contractions, or delivered a baby early in the past.

Fibronectin is a protein that connects the amniotic sac to your uterus -- almost like glue. As the sac begins to separate before birth, your body releases the excess fibronectin.

The test checks the level of fibronectin in your cervix. High levels can mean that you may go into labor early.

The test is simple and safe. Your doctor will take a quick swab from near your cervix. It may be uncomfortable, but it will be quick. Don't have intercourse for 24 hours before the test -- it could cause a false positive result.

You should hear the results within 24 hours. Low levels of fetal fibronectin rule out the possibility of labor within the next two weeks.

High levels don't necessarily mean that you are going into labor. They just indicate you're at higher risk. Your doctor may want to do more tests, such as ultrasounds. You may need drugs to slow down labor. Your baby may need medication to strengthen the lungs.

It depends on your situation. Talk to your doctor.

Cervical length measurement