Description of Treatment/Procedure

Preterm birth is defined as delivery before 37 weeks gestation. Approximately 8 to 10 percent of all births in the U.S. are preterm deliveries (PTD). The incidence of PTD is increased in multiple pregnancies. Various measures have been used to attempt to predict who is at risk for preterm labor (PTL). One potential marker is fetal fibronectin (fFN) detected in cervico-vaginal fluid. Levels of fFN are typically elevated early in pregnancy and again at about 37 weeks gestation. Levels of >=50 ng/ml between 21 and 37 weeks gestation represent a positive test and are not considered normal. Two fFN tests are currently FDA approved. The test is approved as an aid in assessing the risk of PTD and is to be used for patients presenting with signs and symptoms of early pre-term labor with intact amniotic membranes and cervical dilatation of <3 cm at from 24 weeks, 0 days to 34 weeks, 6 days of gestation. The test is not recommended for routine screening of the general obstetric population.

Committee Summary

With regard to the use of fetal fibronectin for the prediction of preterm labor, the ICSI Technology Assessment Committee finds the following:

1. Symptomatic high-risk patients with a negative test result are highly unlikely to experience PTD within the next 7 days. The benefit of testing for fFN is a result of the high negative predictive value of the test. (Conclusion Grade I)
   
2. Testing for fFN is a safe procedure; the risks and limitations of the test are related to the false negative rate and the false positive rate.
   
3. The clinical importance of a positive test remains unclear.
   
4. The fFN test is not recommended as a screening test for asymptomatic patients, regardless of risk status.