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

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.