Fetal fibronectin status and cervical length in women with threatened preterm labor and the effectiveness of maintenance tocolysis

J Matern Fetal Neonatal Med. 2016;29(10):1556-61. doi: 10.3109/14767058.2015.1053863. Epub 2015 Jun 24.

Abstract

Objective: To assess the effect of maintenance tocolysis in women who are at high or low risk for preterm delivery according to fetal fibronectin (fFN) status and cervical length (CL).

Study design: We compared the risk of preterm delivery in fFN pos and fFN neg women and in women with a CL <15 mm and ≥15 mm, by using the Cox regression. Differences between the effectiveness of maintenance tocolysis in high- and low-risk women were assessed by using an interaction term.

Results: 122 fFN tests were taken, of which 50 were fFN pos. CL was measured in 236 women, of whom 52 women had a CL <15 mm. The median gestational age at delivery was lower in fFN pos women; fFN pos women had a higher hazard for preterm delivery at any point of time (HR 4.7; 95% CI 2.9 to 7.6). Comparable results were seen for CL. Neither fFN status nor CL did alter the effect of maintenance tocolysis, which was ineffective in the total randomized group, on the risk of preterm delivery (p for interaction = 0.87 for fFN and 0.18 for CL).

Conclusion: Maintenance tocolytic therapy with nifedipine is ineffective and not dependent on fFN or CL status.

Keywords: Cervical length; fetal fibronectin; maintenance tocolysis.

Publication types

  • Comparative Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Cervical Length Measurement*
  • Female
  • Fibronectins / analysis*
  • Humans
  • Nifedipine / therapeutic use
  • Obstetric Labor, Premature / prevention & control*
  • Pregnancy
  • Tocolysis / statistics & numerical data*
  • Tocolytic Agents / therapeutic use
  • Young Adult

Substances

  • FFN protein, human
  • Fibronectins
  • Tocolytic Agents
  • Nifedipine