Fetal fibronectin test

Fetal fibronectin is a protein that acts as a "glue" during pregnancy, attaching the amniotic sac — the fluid-filled membrane that cushions your baby in the uterus — to the lining of 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.

If your health care provider is concerned about preterm labor, he or she might test a swab of secretions near your cervix for the presence of fetal fibronectin between week 22 and week 34 of pregnancy. A positive fetal fibronectin test is a clue that the "glue" has been disturbed and you're at increased risk of preterm labor.

Why it's done Risks How you prepare What you can expect Results

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 prescribing medication to enhance the baby's lung maturity. If the fetal fibronectin test is negative, you can be assured that your pregnancy is likely to continue for at least another week.

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