Why it's done

The fetal fibronectin test is used to rule out preterm labor. It's generally not useful for women who are at low risk of preterm labor, but it can provide valuable information for women who have signs or symptoms of preterm labor or those who are at high risk of preterm labor.

If the fetal fibronectin test is positive, your health care provider will take steps to address premature birth — such as administering medication to enhance the baby's lung maturity. If the fetal fibronectin test is negative, you can be assured that you're unlikely to deliver within the next two weeks.