Fetal fibronectin (fFN) testing is performed if a woman is 26 to 34 weeks pregnant and having symptoms of premature labor. The goal then is to intervene to prevent the potentially serious health complications of a pre-term baby.
A cervical or vaginal fluid sample is collected and analysed for fFN, a glycoprotein found at the boundary between the amniotic sac and the lining of the uterus. High levels can be due to causes other than risk of pre-term delivery; therefore, a positive fFN result is not very predictive of preterm labor and delivery. However, a negative fFN result is highly predictive that preterm delivery will not occur within the next 7-14 days. Since there are risks associated with treating a woman for premature labor (in anticipation of a premature delivery), a negative fFN can reduce unnecessary hospitalisations and drug therapies.
See more test detail at US Lab Tests Online site
Other links: March of Dimes: Fetal fibronectin