What the experts say
Among the existing risk factors for preterm birth, fFN is the most powerful independent predictor of preterm birth <32 weeks, even more so than prior preterm birth or cervical length.
In the NIH Preterm Prediction Study of 2929 pregnant women, fFN testing predicted almost two-thirds of the spontaneous preterm births at less than 28 weeks.2 In a study of symptomatic women, 99.2% of women with negative fetal fibronectin test results did not deliver in the next 14 days.3
Clinicians from throughout the country are discovering the benefits of fetal fibronectin. Here’s what a few of them had to say about the test’s usefulness, and how it compares to other methods of assessing preterm labor risk.
Kathryn Shaw, MD, is a perinatologist at White Memorial Medical Center in Los Angeles. She finds fFN testing to be “far superior” to other methods of assessing the risk of preterm delivery. This test has been very useful in identifying patients who are not at risk for preterm birth, and thus allows for less intervention and less disruption of those patients’ lives. It also allows for more timely intervention, based on a positive fFN result, when clinical symptoms are minimal.
Thomas A. Raskauskas, MD, of the North Shore Medical Center in Salem, Massachusetts, finds fFN testing to be “the best method to date” for assessing preterm delivery risk. He tests asymptomatic women with a history of preterm birth or other risk factors for PTB. A woman who had two normal term deliveries presented at 31 weeks with contractions. Her initial fFN test was negative, and a repeat test one week later also was negative. The patient, who was the breadwinner of her family, returned to work one week after the initial evaluation, and is still pregnant at 37 weeks. Because of the reassurance provided by the negative results, she was able to retain her full salary, without losing her maternity benefits.
John M. Thorp, Jr, MD, is a perinatologist and professor of obstetrics and gynecology at the University of North Carolina School of Medicine. The majority of his patients are high risk. Dr. Thorp relies on the high negative predictive value of a fFN test to avoid unnecessary treatment of preterm labor symptoms. He finds the test to be “superior to clinical judgment. Dr. Thorp recalls a patient who was reluctant to become pregnant again due to preterm uterine activity in a previous pregnancy, and who did not want to be “sentenced” to bed rest again. Using the negative predictive value, we were able to avoid unnecessary treatments for her uterine activity, and she was able not only to work until term, but also to care for her child.
Daniel Eller, MD, uses fFN testing in his urban, maternal-fetal medicine practice in Atlanta, Georgia. He tests hospitalized patients with shortened cervices or symptoms of preterm labor and outpatients with shortened cervices or other risk factors for PTD. fFN helps him determine which patients need to be hospitalized and for how long. He says that a negative test result allows him to be less aggressive with tocolytics and hospitalization than he otherwise would be. Dr. Eller’s patients reap the benefits when they avoid weeks or even months of hospitalization by virtue of testing negative. Of one patient in particular, he says: I know she appreciated being home with her family, and she said the negative results gave her a sense of security. In addition, the cost of her maternity care was significantly reduced.”