Risk factors and infant outcomes associated with umbilical cord prolapse: a population-based case-control study among births in Washington State.

Abstract

Our goal was to quantify the magnitude of risk associated with conditions resulting in umbilical cord prolapse and adverse infant outcome after cord prolapse. This population-based case-control study used birth certificate data from 709 cases and 2407 randomly selected controls. Odds ratios were used as measures of association, with stratification performed to control for confounding. Case infants were more likely to weigh < 2500 mg (odds ratio 4.8, 95% confidence interval 3.7 to 6.2) and to born prematurely (odds ratio 2.9, 95% confidence interval 2.2 to 3.7). Other risk factors were breech presentation (birth weight-adjusted odds ratio 2.5, 95% confidence interval 1.7 to 3.9) and being a second-born twin (odds ratio 5.0, 95% confidence interval 3.3 to 11.7). Subsequent adverse infant outcomes included an increased risk of mortality (relative risk 2.7, 95% confidence interval 1.9 to 4.0), with mortality being less likely to occur among cases delivered by cesarean section (relative risk 0.4, 95% confidence interval 0.2 to 0.6). This study confirms previously suspected risk factors and supports clinical management of cord prolapse by cesarean section delivery.