Ambulatory uterine activity monitoring in the post-hospital care of patients with preterm labor.

Care of women with preterm labor has been reported by Katz et al to be enhanced by use of an electronic uterine contraction monitor. We enrolled 76 women with singleton gestations who had been successfully treated for preterm labor into a prospective randomized trial, assigning subjects in a ratio of 1:2 to a group of 27 receiving education and self-palpation (EP) or to a group of 49 receiving education and an ambulatory monitor (EM). Subjects in both groups received an intensive education session at entry and were contacted frequently (5 days/week in EP and daily in EM) thereafter to report symptoms and frequency of contractions. Physicians were advised to adjust the dosage of oral tocolytic to maintain fewer than four contractions per hour. Rates of recurrent preterm labor and preterm delivery did not differ between the groups. Although the sample size in this study is too small to exclude entirely the possibility of alpha error, our inability to demonstrate a difference suggests that the improvement reported by others in pregnancy outcome associated with use of an electronic ambulatory contraction monitor may be the result of daily attention to symptoms and signs of preterm labor.