prior successful TOLAC were independent predictors of successfulTOLAC.

788 Total weight gain and incision to deliveryinterval during cesarean deliveryAnna Girsen1, Sarah Osmundson2, Deirdre Lyell21Oulu University Hospital, Department of Obstetrics and Gynecology, Oulu,Finland, 2Stanford University/Lucile Packard Children’s Hospital, Obstetricsand Gynecology, Stanford, CAOBJECTIVE: To examine the independent effect of total weight gainduring pregnancy on incision to delivery interval (IDI) at cesareandelivery.STUDY DESIGN: Women with singleton gestations undergoing uncom-plicated primary and repeat cesarean deliveries were identified fromthe Maternal Fetal Medicine Unit Network Cesarean Registry. Totalweight gain during pregnancy was examined according to body massindex (BMI) units gained during pregnancy. Total weight gain exam-ined at two cutoffs: �6 or �6 BMI units, as 6 units was estimated to bethe maximum weight gain recommended for a median height Amer-ican woman based on Institute of Medicine guidelines, and at �8 or�8 BMI units, as 8 units was estimated to be the minimum increaseneeded for a median height woman with normal BMI to reach obesityduring pregnancy.RESULTS: Of the 21,051 women included in the analysis, 12,676 (60.2%)underwent a primary and 8,375 (39.8%) underwent a repeat cesareandelivery. No significant difference in IDI was found between women witha total weight gain of �6 vs. �6 BMI units, whereas women who gained�8 vs. �8 BMI units had significantly increased IDI (p�0.01) overall.

Within the group who gained �8 BMI units, a history of at least one priorcesarean was associated with decreased incidence of an IDI �10 minutes(38% vs. 54%, p�0.0001). Across nearly all weight gain groups, the IDIincreased linearly with the number of prior cesarean deliveries (Table).CONCLUSION: Women with increased weight gain during pregnancyhad longer incision to delivery intervals during cesarean delivery. Ahistory of a prior cesarean delivery further prolongs IDI.

789 BMI and operative times at cesarean deliveryAnna Girsen1, Sarah Osmundson2, Mariam Naqvi2, Deirdre Lyell21Oulu University Hospital, Obstetrics and Gynecology, Oulu, Finland,2Stanford University/Lucile Packard Children’s Hospital, Obstetrics andGynecology, Stanford, CAOBJECTIVE: To examine the relationship between body mass index(BMI) and incision to delivery interval and total operative times atcesarean delivery.STUDY DESIGN: Women with singleton gestations undergoing uncom-plicated primary and repeat cesarean deliveries were identified fromthe Maternal Fetal Medicine Unit Network Cesarean Registry.Women were classified by BMI category at time of delivery (normal18.5-24.9 kg/m2, overweight 25.0-29.9 kg/m2, obese 30.0-39.9 kg/m2and morbidly obese �40 kg/m2). Incision to delivery interval (IDI)and total operative times during cesarean delivery were comparedbetween the three groups. Prolonged IDI was defined by �95th per-centile of the normal BMI group, or 18 minutes.RESULTS: Of the 21,051 women included in the analysis, 12,676(60.2%) underwent primary and 8,375 (39.8%) underwent repeat ce-sarean delivery. Overweight, obese, and morbidly obese BMIs wereassociated with both prolonged IDI and increased total operative time(Table). BMI at delivery and the number of prior cesareans were eachsignificantly associated with increased IDI and total operative time(p�0.0001). Each prior cesarean added 1.4 minutes to IDI and 3.6minutes to total operative time concurrently. Each unit of BMI added0.14 minutes to the IDI and 0.57 minutes to the total operative time.When adjusted by the number of prior cesareans, the odds for pro-longed incision to delivery interval significantly increased with eachunit of BMI at the time of delivery [OR 1.05, 95% CI 1.04-1.05,p�0.0001].CONCLUSION: Increasing BMI is associated linearly with increased in-cision to delivery interval and total operative time at cesarean, evenafter adjusting for prior cesarean delivery.

Predicted versus observedsuccess rates for TOLAC

Univariate and multivariate logistic regressionanalysis of baseline patient characteristerics

BMI, body mass index; OR, odds ratio.

*Totals vary for each variable according to available data; **Significant in multivariate analysis.

Incision to delivery intervals,mean (standard deviation)

www.AJOG.org Clinical Ob, Epidemiology, ID, Intrapartum Fetal, Operative Ob, Med-Surg-Diseases, Ob Quality & Safety, Public & Global Health Poster Session V

Supplement to JANUARY 2013 American Journal of Obstetrics & Gynecology S331