How is preterm labor diagnosed?

Updated: May 04, 2021
  • Author: Michael G Ross, MD, MPH; Chief Editor: Carl V Smith, MD  more...
  • Print


Contractions of sufficient frequency and intensity to effect progressive effacement and dilation of the cervix at 24-37 weeks’ gestation are indicative of active preterm labor. If the diagnosis of preterm labor is suspected, but not confirmed, it may be prudent to first obtain a vaginal fetal fibronectin (FFN) sample before pelvic cervical examination. If the diagnosis of preterm labor becomes obvious after the pelvic examination, the FFN specimen can be subsequently discarded. However, if the diagnosis remains in doubt, the FFN specimen can be sent to the lab for analysis.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!