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Journey to Parenthood

How to Know If You’re at Risk for Preterm Birth

James Byrne, M.D.

Chairman, Department of Obstetrics and Gynecology, Santa Clara Valley Medical Center, San Jose, CA

One in 10 infants born in the United States will be delivered prematurely, and this has serious implications for the health of both the mother and the baby. In fact, preterm birth is a leading cause of death among children under 5 years of age, and the rate of preterm births has increased in the past two years. While we don’t always know what causes preterm birth, several studies suggest that screening for fetal fibronectin (fFN) may help assess a woman’s likelihood for delivering early, giving her prenatal team the right information to provide the best care.

What is fetal fibronectin?  

fFN is a glue-like protein that holds the developing baby in the womb. After the 35th week of pregnancy, it begins to break down naturally and is detectable. But if detected before week 35, it signals that an expectant mom’s body might be getting ready for delivery.

What does its presence mean?  ​​​​​​​

Getting screened is as simple as getting a Pap test, which can be conducted during a routine prenatal visit in your midwife or doctor’s office alongside other tests you are already receiving. In fact, studies show that screening for fFN along with a transvaginal ultrasound provide the most accurate assessment of preterm birth.

The absence of fFN indicates there is a less than 1 percent chance you will deliver in the next two weeks. This means you can be discharged without worry and can also avoid unnecessary drug treatment, bed rest and hospitalization.

The presence of fFN means your body is leaking fetal fibronectin, a sign that your body may be getting ready to deliver. However, not everyone with the presence of fFN delivers early. To monitor your ongoing risk, your health care provider can check for fFN as often as every two weeks. Most importantly, knowing that fFN is present during weeks 22 to 35 can help you and your prenatal team take the appropriate steps to ensure the best care for you and your baby.

Who should be screened?

Women with risk factors or symptoms of preterm labor are appropriate for fFN screening. If you think you might be at risk of having an early birth, ask your health care provider about fFN. For more than 20 years, doctors have relied on fFN screening in more than 10 million pregnancies to help identify those truly at risk for preterm delivery, providing mothers the best perinatal care they deserve.

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