Preterm contractions in community settings: II. Predicting preterm birth in women with preterm contractions.

Abstract

To examine risk factors for preterm delivery in women who present to nontertiary care hospitals with preterm contractions. Women who presented to a network of community hospitals in Wisconsin with preterm contractions were followed until delivery. The main outcomes were preterm delivery before completion of 36 weeks of gestation and delivery within 1 week of initial presentation. Of the 266 women presenting with contractions over the 2-year study period, 90% (n=239) consented to participate. Multiple factors were associated with premature delivery, but when examined with a multivariate model, only four (ruptured membranes, multiple gestation, cervical effacement at least 80%, and nonwhite race) were associated with prematurity, whereas five (ruptured membranes, multiple gestation, cervical effacement at least 80%, dilation exceeding 1 cm, and being a nonsmoker) predicted delivery within 1 week. A decision model that combined the presence of ruptured membranes and effacement at least 80% could predict delivery at 34 weeks or less within 7 days of presentation with a sensitivity of 71% and a specificity of 98%. Only two clinical cues (ruptured membranes and effacement of the cervix of 80% or more) can predict premature delivery within 7 days. If these results are confirmed prospectively, women with either of these signs could be targeted for administration of steroids, antibiotics, or transfer to tertiary care facilities.