A randomized multicenter study to determine the efficacy of activity restriction for preterm labor management in patients testing negative for fetal fibronectin

J Perinatol. 2005 Oct;25(10):626-30. doi: 10.1038/sj.jp.7211359.


Objective: To assess the impact of activity restriction (AR) on the incidence of preterm birth in women treated for preterm labor testing negative for fetal fibronectin (fFN).

Study design: Women who were diagnosed with preterm labor and tocolyzed with magnesium sulfate were concurrently screened with fFN for the purpose of subsequent management. Included were consenting patients with negative fFN, gestational age 23 0/7-33 6/7 weeks, cervical dilation < or =3 cm, and minimal vaginal bleeding. Patients were randomized to AR or no AR. Primary study outcome was incidence of preterm delivery and interval from randomization to delivery.

Results: A total of 73 women with negative fFN were randomized (36 with AR, 37 without AR). The overall preterm birth rate was 40%, with 44.4% of patients with AR and 35.1% of patients without AR delivering preterm, p=0.478.

Conclusion: Maternal AR did not impact pregnancy outcome. The incidence of preterm birth in symptomatic women testing fFN negative was higher than previously reported.

Publication types

  • Multicenter Study
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Bed Rest*
  • Female
  • Fibronectins / analysis*
  • Gestational Age
  • Glycoproteins / analysis*
  • Humans
  • Infant, Newborn
  • Magnesium Sulfate / administration & dosage
  • Obstetric Labor, Premature / prevention & control*
  • Pregnancy
  • Pregnancy Outcome
  • Prospective Studies
  • Tocolytic Agents / administration & dosage


  • FFN protein, human
  • Fibronectins
  • Glycoproteins
  • Tocolytic Agents
  • Magnesium Sulfate