At what cervical length should fetal fibronectin (FFN) testing be considered for further evaluation?

Fetal fibronectin (FFN) testing is typically used as a predictive tool for preterm labor, particularly in women who are at risk for premature delivery. The consideration for FFN testing is heavily influenced by the cervical length, which can indicate the status of the cervix and the risk for preterm labor.

A cervical length of 2-3 cm is a critical range where FFN testing is particularly relevant. In this range, there is sufficient concern that labor could be imminent, particularly if the patient is experiencing contractions or has other signs of premature labor. FFN is a glycoprotein that acts as a glue between the amniotic sac and the uterine lining. If present in the vaginal secretions at this cervical length, it suggests an increased risk of preterm delivery within the next two weeks.

This measurement serves as a marker indicating that further evaluation and monitoring may be necessary to manage the risk of preterm birth effectively. It helps clinicians make informed decisions about potential interventions, such as tocolytics or corticosteroids, to aid fetal lung maturity in anticipation of preterm delivery.

In summary, a cervical length of 2-3 cm is significant in the context of FFN testing as it strikes a balance between