1. Ealing Hospital NHS Trust The path from external cephalic version to vaginal delivery – how many does it take? T AN T OH L ICK 1, I LKA T AN 2, P AOLA R ODRIGUEZ 1 Department of Obstetrics & Gynaecology, 1 Ealing Hospital NHS Trust, 2 Northwest London Hospitals NHS Trust, London, United Kingdom INTRODUCTION External cephalic version (ECV) is advocated for pregnant women with breech presentation at term in order to facilitate a safe vaginal delivery 1, 2. Despite ECV, a significant proportion of women will still require lower segment Caesarean section (LSCS) as described in our poster abstract A0725. We sought to determine the number of ECV required to achieve a vaginal delivery in a multi-centred study. METHODS A large retrospective cohort study was conducted on all ECV performed on women who delivered between 01.01.2006 to 31.12.2011 in two London hospitals. Subjects were identified using hospital admission coding for ECV and data extracted from EuroKing electronic maternity records in the first hospital, and obtained from Ciconia Maternity Information System (CMiS) in the second hospital. Subject demographics, pregnancy and labour details were entered into Microsoft Excel for analysis. Birthweight centile was calculated using Perinatal Institute’s UK bulk centile calculator 3. Table 1. Demographics of women with failed and successful external cephalic version. Mean ± SD, Numbers (percentage). p using Student t- test or Chi square test in []. References 1: Royal College of Obstetricians and Gynaecologists. External cephalic version and reducing the incidence of breech presentation. Green-top Guideline No. 20a. London: RCOG; 2010. 2: Royal College of Obstetricians and Gynaecologists. The management of breech presentation. Green-top Guideline No. 20b. London: RCOG; 2006. 3: Gardosi J, Francis A. Customised Weight Centile Calculator – GROW-Centile v.5.12/6.2 2009. Gestation Network, www.gestation.net (v. 5.12: individual; v 6.2: bulk centiles) RESULTS During the 6 year period, 93 and 140 ECV were performed in the two hospitals. Four cases were excluded as 2 had insufficient data, 1 had ECV for 2nd twin, and 1 being the 2nd ECV attempt for a woman. A total of 229 cases were analyzed and their demographics are as shown in table 1. In the 229 ECV, 153 (66.8%) remained non-cephalic including 1 transverse, and 76 (33.2%) became cephalic. The outcomes are shown in table 2. Of the unsuccessful ECV, 13 (8.5%) became cephalic at delivery in whom 6 had elective and 6 emergency LSCS; only 1 achieved a normal vaginal delivery. In those that remained breech, 110 (71.9%) had elective LSCS, 28 (18.3%) emergency LSCS and 2 (1.3%) breech vaginal delivery. The vaginal delivery rate was 2.0%. Conversely, 6 (7.9%) successful ECV reverted to breech presentation at delivery in whom 2 had elective and 3 had emergency LSCS; 1 presented in labour and had a breech vaginal delivery. In those that remained cephalic at delivery, 3 (3.9%) had elective and 16 (21.0%) had emergency LSCS. The rest of the 51 (67.1%) achieved vaginal delivery including 4 ventouses and 2 forceps deliveries. The vaginal delivery rate was 68.4%. Overall, in the 229 ECV, 174 (76.0%) had a LSCS while only 55 (24.0%) achieved a vaginal delivery, including 3 breech vaginal delivery. The number of ECV required to achieve a vaginal delivery was 4.2. CONCLUSIONS About 1 in 3 ECV were successful. Although successful ECV was more likely to have a vaginal delivery, 1 in 3 will still require LSCS. Overall the number needed to treat to achieve a vaginal delivery for breech presentation was 4.2. The risk of meconium liquor remains higher in women with successful ECV even when the analysis was restricted to deliveries between 37 +0 to 40 +0 weeks. This may reflect the stress exerted on the fetus to achieve a successful ECV. The significance of this require further studies. Correspondence: tohlick.tan@nhs.net Table 2. Outcome of women with failed and successful external cephalic version. Mean ± SD, Numbers (percentage). p using Student t-test or Chi square test in []. Failed ECVSuccessful ECVp n15376 Maternal age, years30.3± 5.431.5± 5.20.1266 BMI, kg m -2 25.7± 5.224.6± 4.10.1287 Primigravida71(47.0%)51(68.0%)[0.0289] Failed ECVSuccessful ECVp n15376 Meconium liquor rate6(4.0%)19(25.0%)[0.0001] Meconium at 37 +0 -40 +0 /405(3.6%)11(33.3%)[0.0001] Caesarean section rate150(98.0%)24(31.6%)[0.0001] Blood loss, ml549± 258498± 4800.3028 Male infant rate75(49.0%)34(44.7%)[0.5411] Birth weight, g3,273± 4593,408± 4890.0414 Small for dates <10 th centile40(26.1%)16(21.1%)[0.3986] Large for dates >90 th centile10(6.5%)2(2.6%)[0.2118] Head circumference, cm34.8± 1.434.9± 1.40.6090 Length, cm53.1± 4.152.4± 3.60.3798