109: The association between mid-trimester cervical length and cesarean delivery at term

109 The association between mid-trimester cervical length and cesarean delivery at term Emily Miller, William Grobman Northwestern University, Obstetrics and Gynecology, Chicago, IL OBJECTIVE: An ultrasonographically diagnosed short cervix has been associated with an increased risk of preterm birth, but the obstetric consequences of longer cervical lengths have been less well defined. The objective of this study was to determine the association between cervical length and cesarean delivery among women at term. STUDY DESIGN: This is a cohort study of women with a singleton gestation who underwent routine mid-pregnancy transvaginal cervical length assessment and delivered at term. Women who underwent planned cesarean delivery without intent to labor were excluded from analysis. Women were grouped into quartiles based on cervical length, and the association of their cervical length quartile with cesarean delivery was determined in both univariable and multivariable analysis. RESULTS: 5806 subjects were included in this analysis, of whom 58.1% were nulliparous. There were multiple differences among women in the different cervical length quartiles (Table). The frequency of cesarean delivery among the cohort was 18.9%. As cervical length increased, the chance of cesarean delivery increased as well (14.7%, 19.5%, 19.1%, and 22.4% from the 1st through 4th quartiles, respectively). After controlling for potential confounding factors, cervical length quartile remained significantly associated with an increased odds of cesarean for the second (aOR 1.49, 95% CI 1.18-1.88), third (aOR 1.47, 95% CI 1.16-1.85) and fourth (aOR 1.89, 95% CI 1.502.38) quartiles, compared to the first quartile. This relationship held true for nulliparous as well as multiparous women. CONCLUSION: Increasing mid-trimester cervical length is associated with increasing frequency of cesarean delivery in both nulliparas and multiparas. Preparatory uterine changes that enable successful labor may be initiated as early as the mid-trimester. 110 Evidence to support the safety and efficacy of vaginal delivery of twins gestation complicated by very low birthweight of second twin Eran Barzilay, Hila de Castro, Jigal Haas, Eyal Sivan, Eyal Schiff, Shali Mazaki-Tovi, Yoav Yinon Sheba Medical Center, Tel-Aviv University, Obstetrics and Gynecology, TelHashomer, Israel OBJECTIVE: To determine whether neonatal outcome is associated with the mode of delivery in very low birthweight twins. STUDY DESIGN: This was a retrospective cohort study. Inclusion criteria included: 1) twin gestation; 2) second twin birthweight of 1500 grams. Exclusion criteria included: 1) gestational age at delivery of less than 24 gestational weeks 2) fetal demise of one or both twins. A total of 206 twin gestations met the criteria and patients were classified into 2 groups according to the planned mode of delivery: 1. Cesarean delivery (n 152) and 2. Vaginal delivery (n 54). In the vaginal delivery group 24 pairs were cephalic-cephalic, 28 pairs were cephalic-non cephalic, and 2 pairs were non cephalicnon cephalic. The rates of Apgar score 7 at 5 minutes and cord blood PH 7.1 in either twin A or B were determined in the two groups. RESULTS: The mean gestational age at delivery was 31 weeks in the cesarean delivery group compared to 30 weeks of gestation in the vaginal delivery group (p 0.01). However, the mean birthweight of both twins was similar among the two groups (Twin A: 1452 grams vs. 1358 grams, p 0.18 and Twin B: 1186 grams vs. 1182 grams, p 0.9 respectively). There were no significant differences between the cesarean and vaginal delivery groups in the rates of low Apgar score (Twin A: 4.0% vs. 1.9%, p 0.5 and Twin B: 9.7% vs. 3.7%, p 0.2) and cord PH 7.1 (Twin A: 2.4% vs. 0%, p 0.3 and Twin B: 1.7% vs. 0%, p 0.4). A sub-group analysis of the vaginal delivery group revealed comparable rates of cesarean section (8.3% Vs 3.3%, p 0.4) as well as neonatal Apgar score 7 among the cephalic-cephalic and cephalicnon cephalic groups (Twin A: 4.2% vs. 0%, p 0.3 and Twin B: 0 vs. 6.7%, p 0.2). CONCLUSION: Vaginal delivery of very low birthweight twins is a safe regardless of second twin presentation. This information should provide reassurance for pregnant women and clinicians alike.