: Negative fFN, Who is Still Managed Aggressively and Does it Help?

 Elevated levels of fetal fibronectin  (fFN) in cervicovaginal secretions beyond 22 weeks gestation are used as  a predictor of preterm birth in patients suspected of being in preterm  labor. Previous studies have documented a negative predictive value of  97-99.5% of delivering within 7 days of testing. Providers sometimes  disregard a negative result and manage the patient aggresively. Our  objective was to identify which patients with a negative fFN were being  managed aggressively, and if outcomes were improved with such  management.

 Charts were reviewed from 121 patients  evaluated in our obstetrical triage unit for "rule-out preterm labor"  with negative fFN results over a 2 year period. Patients with singleton  pregnancies seen between 22 and 33 6/7 weeks were included. Patient  characteristics, management, and outcomes were recorded.

 80 patients were managed expectantly, 41  were managed aggressively (18 were admitted, 29 were given tocolytics,  15 received steroids, 8 received antibiotics). The group managed  aggressively were more likely to be dilated 1cm or more (27% vs. 3%,  p<.001), or contracting at least every 8 minutes (68% vs. 23%,  p<.001). Parity, prior preterm births, age and gestational age at  testing were similar between the groups. None of the patients delivered  within 7 or 14 days of fFN testing. The rates of preterm birth <37  weeks, <35 weeks and <32 weeks, and fFN to delivery interval were  similar between the 2 groups. There was no advantage seen to aggressive  management even when analyzing only the "high risk" patients (dilated  2cm, effaced >80%, contracting at least every 4 minutes, or prior  preterm birth).

 Patients with risk factors for preterm  birth are more likely to be aggressively managed in the face of a  negative FFN. This aggressive management does not improve outcomes.

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0002-9378/$ - see front matter
 doi:10.1016/j.ajog.2006.10.853
 American Journal of Obstetrics and Gynecology 
 

Volume 195, Issue 6, Supplement S (December 2006)