21st World Congress on Ultrasound in Obstetrics and Gynecology Oral poster abstracts by mean RI ≥ 0.65. Adverse gestational outcome were considered: Caesarean section (CS) for fetal distress in labor, intrauterine fetal death, placental abruption, small for gestational age neonates. Gestational age at delivery and birth weight were also considered. Results: Uterine artery velocimetry was performed in 929 pregnant women: 151 (16.3%) were at low risk and 778 (83.7%) at increased risk of placental insufficiency. Uterine artery velocimetry was normal in 766 patients (82.5%) and abnormal in 163 (17.5%). An adverse gestational outcome occurred in 73 cases (7.9%), in particular 62 cases (6.7%) had an abnormal CTG that required a CS, 6 cases (0.7%) had placental abruption and 5 cases (0.5%) intrauterine death. An abnormal uterine artery velocimetry was related with a significantly higher incidence of adverse gestational outcomes (15.3 vs. 6.3% P < 0.001) as well of CS for fetal distress (13.5 vs. 5.2% P < 0.001). The group with increased uterine artery resistances had a lower gestational age at delivery (35.3 vs. 38.7W P < 0.001), a lower mean birth weight (1750 vs. 3000 g P < 0.001) and a higher incidence of total CS (71.7 vs. 38.9% P < 0.001) when compared with the group with normal uterine artery Doppler. Conclusions: Abnormal uterine artery velocimetry in third trimester identifies a group of pregnancies at increased risk of unfavourable gestational outcome, in particular at risk of Caesarean section for fetal distress in labour. In presence of increased uterine artery resistances a closer fetal surveillance during labour is therefore recommended. OP16.11 Uterine artery Doppler flow studies in late 2 nd trimester for prediction of adverse pregnancy outcomes in low risk populations H. Muto , M. Matsushita, T. Murakoshi, H. Naruse, Y. Torii Division of Obstetrics and Perinatology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan Objectives: In high risk pregnancies, uterine artery Doppler flow examination have been reported valuable to predict of pre-eclampsia (PE) and fetal growth restriction (FGR), however, it has scarcely been evaluated in low risk populations. The aim of this study is to analyze the association with abnormal uterine artery (UtA) Doppler flow and adverse pregnancy outcomes in low risk populations. Methods: This is a prospective observational study. A total of 880 scans were performed in late 2 nd trimester from 2009 to 2010. Two hundred and sixty-three pregnancy women met inclusion criteria as follows: (1) singleton pregnancy; (2) absence of congenital malformations (including cromosomopaties); (3) low risk pregnancy determined by Japanese pregnancy risk score; (4) each neonate was born in our institution. The UtA were examined transabdominally; the pulsatility index (PI) of the left and right arteries were measured, and the mean PI was calculated. Elevaterd UtA-PI was defined as the figure above 95 percentile. In addition the presence of notch at least one-side was determined. Small for gestational age (SGA) was defined as birth weight below 10 th percentile according Japanese standards (Ogawa, 1998). Relations between UtA Doppler anomalies variables (SGA infant and maternal PE) were analyzed by the χ 2 or Fisher exact tests. Results: Mean gestational age at delivery was 39 weeks (28–42 weeks). Two women developed PE (0.7%), 29 had SGA infants (11.0%). Among elevated UtA-PI cases, 1 developed PE (10.0%, P = 0.075) and 4 had SGA infants (40.0%, P = 0.016). Among presence of notch group, 2 PE (3.6%, P = 0.043) and 11 SGA infants (20.0%, P = 0.020). Conclusions: In low risk pregnancy, uterine arterial Doppler flow velocimetry in late 2 nd trimester might predict SGA infants. While differences were not observed any abnormal uterine artery Doppler anomaly for development of PE because there were few number of the development of PE in this study. OP17: FETAL THERAPY OP17.01 MRI findings in MC twin pregnancies after intra-uterine fetal death S. Lipitz , C. Hoffman, Y. Yinon, L. Gindes, G. Greenberg, E. Sivan, B. Weisz Obstetrics and Gynecology, Sheba Medical Center, Tel-Hashomer, Israel Objectives: To determine if MRI can diagnose acute hypoxic- ischemic cerebral lesions in the survivor of a MC twin pregnancy shortly following spontaneous or iatrogenic fetal death. Methods: A prospective cohort of all cases of IUFD in MC pregnancies was evaluated by fetal sonography, T2-MRI and DWI. During the study period 32 cases of IUFD were evaluated. Fifteen cases were of unintended single IUFD in MC twin pregnancies; 5 cases were complicated by spontaneous IUFD and 10 cases were iatrogenic, after treatment of severe TTTS (twin-to-twin transfusion syndrome) by laser ablation of communication anastomoses. These were compared to a third group of 17 pregnancies treated by selective termination (bipolar or radiofrequency) due to severe complications in MC pregnancies. Results: In 2/5 (40%) of pregnancies with spontaneous death MRI showed severe findings of cerebral infarct (Table: cases 1–2). In 1/10 cases treated by laser, MRI showed findings of severe temporal lobe and periventricular infarcts (case#3). This was seen only by DWI. In another two cases (2/10), MRI showed suspected germinal matrix (GM) bleeding (cases 4–5). In 1/17 cases treated by selective termination, DWI showed bilateral cerebral ischemia which was also evident by T2-MRI (case#6). In another case, MRI findings OP17.01: Table Patient # GA @IUFD GA @MRI Comments US findings DWI Findings (days after fetal death) MRI T2 findings 1 36 36 IUFD 2 days after normal US Elevated MCA-PSV Positive–Recent posterior infarct (2d) Brain edema 2 32 32 IUFD 4 days after follow up due to stage 1 TTTS. Normal Positive–Unilateral recent infarct (4d) Contra lateral previous infarct 3 23 24 TTTS stage II treated by aser ablation at 18 weeks. Normal Positive- Temporal horn infarct (4d) Normal 4 22 23 TTTS stage II treated by aser ablation at 22 weeks. Normal Suspected GM bleeding (5d) Normal 5 24 24 TTTS stage III treated by laser ablation at 23 weeks. Normal GM bleeding (1d) GM bleeding seen also at 27 weeks. 6 22 22 sIUGR treated by selective reduction (RF) Normal, later ventriculomegaly. Cerebral ischemia with inract cerebellum (1d) Suspected edema later (27 weeks) developed to bilateral cerebral ischemia. 7 21 21 sIUGR treated by selective reduction (Bipolar) Normal GM bleeding (5d) Normal, than suspected GM bleeding (25w) which resolved (32 w) 8 23 23 TTTS stage III with IUGR treated by selective termination (Bipolar). Normal Focal changes in basal ganglia (4 d) Focal hypointense signal in BG. 104 Ultrasound in Obstetrics & Gynecology 2011; 38 (Suppl. 1): 56–167