471: Predicting admission-to-delivery interval of patients with preterm uterine contractions

Abstract

Multiple variables are used to predict preterm delivery with intermediate efficacy. Our goal was to identify factors that predict delivery within 7 days of initial presentation with preterm uterine contractions, thus allowing for optimal management with admission and steroid therapy. IRB approval was obtained for a retrospective chart review of patients between 21+6 to 34+6 weeks gestation presenting to our Birthing Unit with preterm contractions between February 2006 to April 2008. Maternal delivery records were analyzed for demographic and delivery information, including gestational age, history of preterm birth, history of LEEP and cervical dilation. Descriptive statistics and stepwise regression analysis were used to identify variables to predict delivery within 7 days. 124 patients were admitted to our institution with preterm contractions, with 35 (28%) of these women delivering within 7 days. Significant predictors of delivery ≤7 days on univariate analysis included cervical dilation, gestational age, and prior term delivery. BMI, history of preterm delivery or prior LEEP were not significant predictors. On multivariable analysis, gestational age and cervical dilation at the time of admission accounted for 39% of the variability in probability of delivery within 7 days. Gestational age was significantly greater in women that delivered ≤7 days (32.2 ± 0.6 vs. 30.0 ± 0.4 weeks; p < 0.001). 59% of women with cervical dilation of ≥4cm delivered ≤7 days. Gestational age and cervical dilation at the time of admission for preterm uterine contractions were most predictive of delivery within 7 days.Tabled 1Delivery within 7 days of presentationDelivery > 7 days of presentationOdds Ratio (95% CI)Admit Dil (cm)4.1 ± 0.41.4 ± 0.12.56 (1.78 – 3.68)Gest Age (wks)32.2 ± 0.630.0 ± 0.41.25 (1.08 – 1.44)Prior Term Del62.9%40.9%2.44 (1.09 – 5.48) Open table in a new tab