Fetal Fibroin Length from Gestational Age (Fetal Fibronectin Test)

Why This Test Is Done

Your healthcare provider may recommend this test if you have symptoms like mild uterine contractions, vaginal bleeding, or cervical changes (such as dilation or effacement) between 24 and 34 weeks of pregnancy. It’s also sometimes used to check if your cervix is more likely to open early, which could lead to preterm birth. This test helps guide decisions about monitoring or treatment to reduce risks for both you and your baby.

How the Test Works

A small sample of fluid from your cervix is collected using a swab. The fluid is then tested for fetal fibronectin, a protein that appears in the amniotic fluid when the cervix is softening or preparing for labor. If the test is positive, it suggests a higher chance of preterm labor within the next two weeks.

What the Results Mean

A positive result (detecting fetal fibronectin) means there’s a moderate risk of preterm labor occurring within the next 10–21 days. A negative result means the risk is lower, but it doesn’t rule out preterm labor entirely. Your healthcare provider will discuss the results with you and may recommend additional tests or close monitoring.

Next Steps After the Test

If the test shows a higher risk, your provider might suggest bed rest, pelvic rest, or other interventions to delay labor. If the risk is low, they may continue monitoring with regular check-ups. Always follow your provider’s advice based on your specific situation.