Activity restriction and risk of preterm delivery .

PURPOSE: We sought to determine whether activity restriction (AR) in a cohort of women at high risk for preterm delivery is associated with the risk of preterm delivery.

MATERIALS AND METHODS: This is a secondary analysis of the Maternal-Fetal Medicine Units MFMU's Preterm Prediction Study; a multicenter prospective cohort study designed to identify risk factors of preterm birth (PTB). The study group consisted of women with a singleton gestation that at their first study visit (23-24 weeks) had at least one of the following criteria: patient reported contractions, severe back pain, a cervical length <15 mm, spotting, protruding membranes, or positive fetal fibronectin. Women were assessed for AR at a 27- to 29-week study visit. Associations between AR and preterm delivery (<37 weeks) were examined through logistic regression models before and after adjustment for confounders.

RESULTS: Of the 1086 women that met the inclusion criteria, 16.5% (n = 179) delivered preterm. In this cohort, 9.7% (n = 105) of women were recommended AR, with 37.1% (n = 39) having a PTB. In the group not recommended AR (n = 981), 14.3% (n = 140) delivered preterm.

CONCLUSION: In this cohort of women at high risk for PTB, activity restriction was associated with an increased risk of PTB. The use of AR in this population should be discouraged.