19th World Congress on Ultrasound in Obstetrics and Gynecology Oral communication abstracts acquisition. Aim of this study was to compare the performance of the AN24 with Doppler FHR monitoring in high risk patients requiring prolonged testing. Study design: Prospective observational study of singletons admitted for fetal monitoring. Each AN24 session was matched 2 : 1 for gestational age (GA), body mass index (BMI), and time of day with a control recording using external Doppler. Percentage of FHR capture was compared for both methods. Results: 93 monitoring sessions (31 cases, 62 controls) were analyzed after verifying proper matching by ANOVA. GA median was 29.0wks [23.1–39.5], median BMI 26.6 [20.1–42.2] and mean monitoring duration 751 minutes [73-1410]. Rate of good capture recordings (> 60%) was similar p>0.05. Overall percentage capture of the FHR was better with Doppler (88% vs 58%, Mann Whitney < 0.001). This difference was primarily due to sessions with low AN24 capture between 26 – 33.6wks ( ** =p<0.001, table). Outside this gestational age window both devices perform similar. Conclusion: Monica AN24 fetal ECG monitoring is equivalent Doppler technology early and late in gestation. For extended monitoring between 26–34 weeks, the AN24 technology requires improvement to overcome FHR capture limitations that are most likely due to increased vernix caseosa formation. Supporting information can be found in the online version of this abstract. OC29.09 Abnormal brain microstructure in small for gestational age term fetuses with normal umbilical artery Doppler M. Sanz-Cortes 1 , F. Figueras 1 , N. Bargallo 2 , N. Padilla 1 , I. Amat-Roldan 1 , E. Gratacos 1 1 Department of maternal-fetal medicine (ICGON), Hospital Clinic-University of Barcelona, IDIBAPS, CIBERER, Barcelona, Spain; 2 Department of Radiology, Hospital Clinic-University of Barcelona, Barcelona, Spain Objectives: Small for gestational age (SGA) has traditionally been considered to have a good neurological outcome, but recent evidence suggests that there is an increase in the prevalence of neurocognitive disorders. Our objective was to assess microstructural brain differences between adequate for gestational age (AGA) and SGA fetuses, using diffusion weighted imaging (DWI). Methods: Eight SGA and five matched AGA singleton fetuses were evaluated with DWI at 37 weeks to study their cerebral water diffusion. DW images were used to calculate the anisotropic diffusion coefficients (ADC) at the level of basal ganglia, frontal and occipital white matter, the corpus callosum and the pyramidal tract. Results: ADC levels in the pyramidal tract were increased in SGA fetuses (p=0.04). A trend for higher ADC values in SGA fetuses was observed in the frontal and occipital lobe and corpus callosum. ADC values were found linearly increased from inferior to superior structures both in AGA (p=0.04) and SGA (p=0.03). Conclusions: Our findings suggest that SGA is associated with microstructural brain changes before birth. These preliminary data merit further investigation in larger studies. OC29.09: ADC values from SGA and AGA fetuses AGA n= 5 SGA n= 8 p Mean frontal lobe diffusivity 124.77 (6.92) 132.37(11.2) 0.2 Mean occipital lobe diffusivity 128.35 (9.30) 132.81(11.7) 0.49 Mean basal ganglia diffusivity 109.62(4.08) 109.87(9.03) 0.95 Pyramidal Tract 105.11(11.07) 119.87(12.03) 0.04 Corpus callosum 120.31(10) 127.3(11.34) 0.28 Results are expressed as mean and standard deviation. ADC values ×10-5 cm/s. OC29.10 Abnormal brain metabolism in small for gestational age term fetuses with normal umbilical artery Doppler M. Sanz-Cortes 1 , F. Figueras 1 , N. Bargallo 2 , N. Padilla 1 , I. Amat-Roldan 1 , E. Gratacos 1 1 Department of Maternal-Fetal Medicine (ICGON), Hospital Clinic-University of Barcelona, IDIBAPS, CIBERER, Barcelona, Spain; 2 Department of Radiology, Hospital Clinic-University of Barcelona, Barcelona, Spain Objectives: Small for gestational age (SGA) has traditionally been considered to have a good neurological outcome, but recent evidence suggests that there is an increase in the prevalence of neurocognitive disorders. Our objective was to assess the metabolic brain differences between adequate for gestational age (AGA) and SGA fetuses using magnetic resonance spectroscopy (MRS). Methods: Eight SGA and five matched AGA singleton fetuses were evaluated with MRS at 37 weeks to measure markers of brain metabolism. A voxel was located on the left frontal lobe using a short echo time. The metabolic spectrum of N-Acetyl-Aspartate/choline, choline/creatine, inositol/choline and creatine/choline were analyzed. Results: As compared with controls, SGA fetuses showed a significant increase in inositol/choline (SGA=0.57.AGA=0.25; p=0.04), and a trend for lower values in choline/creatine (SGA= 2.12 AGA= 5.21; p=0.09). Conclusions: These preliminary data support the notion that SGA is associated with abnormal brain metabolism in utero. These findings merit further investigation in larger studies. Supporting information can be found in the online version of this abstract. OC30: USING ULTRASOUND TO ASSESS UROGYNECOLOGY PATIENTS OC30.01 Vaginal wall thickness is related to the degree of vaginal prolapse D. C. Panayi , V. Khullar, R. Fernando, G. A. Digesu, P. Tekkis Urogynaecology, Imperial College Healthcare, London, United Kingdom Objectives: Studies have shown changes in vaginal tissue in vaginal prolapse including reduction of collagen, elastin and smooth muscle. The aim of this study was to assess how vaginal wall thickness was related to vaginal prolapse. Methods: We recruited 350 women, 243 had symptomatic prolapse, all quantified using the POP-Q score. Women had an ultrasound and the thickness of the vaginal wall was determined at the bladder neck, at the level of the dome of the bladder, and at the anterior fornix, and at the level of the anorectal junction, the rectum and the posterior fornix, posteriorly. This included the full thickness of tissue between the vaginal lumen and the prolapsed pelvic organ and was termed vaginal wall thickness (VWT). Women were grouped into grades of severity of prolapse from grades 1 to 3. POP-Q scores of −2 to −1 was grade 1, −1 to 0 was grade 2, and scores greater than 1 where categorised as grade 3. Women with scores of less than −2 were grade 0. Scores were compared to VWT at the three anatomical sites on the anterior and posterior vaginal walls. Results: VWT reduced as prolapse grade increased until the prolapse extended beyond the introitus. There was a statistically significantly higher mean vaginal wall thickness in women with grade 3 prolapse (scores > 0) (p<0.001 Kruskal Wallis) compared to women with grade 1 or 2 prolapse contained. 58 Ultrasound in Obstetrics & Gynecology 2009; 34 (Suppl. 1): 1–61