What is Fetal Fibronectin?
Fetal fibronectin (fFN) is a protein that acts as a "biological glue" during pregnancy, helping to attach the fetal sac to the uterine lining. It is produced by fetal cells and can be found in cervical and vaginal secretions. The presence of fFN is typically expected during early pregnancy and towards the end of pregnancy, near labor.
Why is Fetal Fibronectin Significant?
The detection of fFN in cervical and vaginal secretions between weeks 22 and 34 of gestation can be a significant indicator. When fFN is present during this period, it may suggest an increased risk of preterm labor. Thus, it serves as a useful biomarker in evaluating the risk of premature birth.
How is the Fetal Fibronectin Test Performed?
The fFN test is a non-invasive procedure usually performed during a pelvic exam. A speculum is inserted into the vagina, and a swab is used to collect secretions from the cervix. This sample is then sent to a lab for analysis. It is important to avoid any vaginal examinations, sexual intercourse, or use of any vaginal products 24 hours before the test to avoid contamination of the sample.
When is the Fetal Fibronectin Test Recommended?
The fFN test is typically recommended for pregnant women who are showing symptoms of preterm labor, such as uterine contractions, pelvic pressure, or changes in vaginal discharge. It may also be used for women who are at high risk of preterm birth due to previous preterm deliveries or other complications.
What Do Positive and Negative Test Results Mean?
A negative fFN test result is generally reassuring and suggests that the likelihood of delivering within the next two weeks is very low. A positive test result, on the other hand, indicates that there is a higher risk of preterm labor, but it does not guarantee that preterm birth will occur. Positive results often necessitate closer monitoring and may lead to interventions aimed at delaying labor, such as corticosteroids to mature the fetal lungs or medications to inhibit contractions.
Limitations and Considerations
While the fFN test is a valuable tool, it is not without limitations. False positives can occur, and a positive result does not definitively predict preterm labor. Additionally, the test is not useful for women who are less than 22 weeks or more than 34 weeks pregnant, as fFN is normally present outside of this window. The test should be used in conjunction with other assessments and clinical evaluations to inform decisions about patient care.Conclusion
Fetal fibronectin is an important biomarker in assessing the risk of preterm labor. Its presence in cervical and vaginal secretions during mid-pregnancy can provide critical information for managing high-risk pregnancies. By understanding the implications of fFN test results, healthcare providers can better plan interventions to improve outcomes for both the mother and the fetus.
