31 August–4 September 2003, Paris, France Poster abstracts be positive (sports, hobbies, ...) but is negative (addictive habits to work, alcohol, tobacco, ...) in a significantly higher proportion than in the AIDS care field (same items). Conclusion: Fetal ultrasonography is a high risk situation of burn out for practitioners. P058c Prenatal sonographic diagnosis of hemivertebra B. Weisz , A. Shindler, V. H. Eisenberg, S. Lipitz, R. Achiron and Y. Zalel Sheba Medical Center, Israel Objective: To describe our experience in prenatal diagnosis of hemivertebra. Methods: The present study presents a case series of six consecutive cases identified among cases referred to our tertiary medical center over a three-year period. All fetuses were scanned by high-resolution real-time scanners. The apparent vertebral anomaly was assessed in real-time manner by a joint team of Obstetricians, Sonographers and Pediatric orthopedic surgeons. A complete anomaly survey of other fetal organs was performed on each fetus. All patients were given proper counseling by the same joint team. All patients had detailed obstetric and neonatal follow-up. Prenatal sonograms, neonatal medical records and clinical course were evaluated retrospectively. Results: During the period of 1999 and 2002, six cases of hemivertebrae were identified in our department. Gestational age at diagnosis was 14–23 weeks. Two patients conceived by ART. Associated anomalies and outcome are described in Table 1. Conclusion: Diagnosis of isolated hemivertebra is associated with favorable outcome. The three key factors in achieving an optimal spine at maturity – Early diagnosis, anticipation and prevention of deterioration might be enhanced by our joint multidiscipline approach to the diagnosis of skeletal anomalies. P058d Modelling fetal nuchal-translucency in the first trimester of pregnancy: disclosure of a practitioner effect V. Equy *, T. P. Baum†, C. Cans*, C. Lavergne‡, J. C. Pons*, M. Althuser* and P. S. Jouk* *CHU Grenoble, France; †Facult´ e de M´ edicine de Grenoble, France and ‡INRIA Rh ˆ one Alpes, France Fetal nuchal translucency (NT) is an ultrasonographic sign used for the screening of trisomy 21 in the first trimester of pregnancy. The introduction of the combined risk method lead recently to evaluation needs of the medical practice in this NT measurement. In order to assess whether it was possible to identify a practitioner effect on the fetal NT measurement, we decided to conduct a retrospective study. The data were collected between 1996–1999, from 12 different French practitioners, and resulted in 4557 units available for modelling methods. The proportion of nuchal translucency above 2.9 mm was 1.4%. After multivariate analysis, the variables retained for their influence on the NT were the fetal heart rate, the crown rump length and the practitioner effect. The amount of variance explained by the practitioner effect, 14%, was as important as the variance explained by the biometrics variables, 13%. With the results of this study we highlighted the potential influence of the practitioner on the NT measurement, and thus on the number of amniocentesis performed. This is in favour of recommending training and quality controls before any use of the combined risk method. Keywords: fetal nuchal translucency; trisomy 21; ultrasound sign; measurement; modelling. P059 Antenatal surveillance of fetal abnormalities – the importance of a population based Birth Defect Registry J. V. K. Tan , K. K. H. Tan and G. S. H. Yeo KK Women’s and Children’s Hospital, Singapore Aim: To review the cases of antenatally diagnosed fetal abnormalities in KK Women’s and Children’s Hospital from January 2001 to December 2002. Methods: All cases of antenatally diagnosed fetal abnormalities of patients booked at our hospital during this period, comprising low and high risk pregnancies, were registered with the hospital-based Birth Defect Registry. Diagnosis was made through sonography, karyotyping and other molecular tests like DNA analysis. Data from these cases and the postnatal outcomes were analysed for clinically relevant information. Results: In this period, there were 30124 deliveries at our hospital and 1633 (5.4%) antenatally diagnosed fetal abnormality cases. These include 669 (40.1%) cases of ultrasound markers for aneuploidy (echogenic bowel, choroid plexus cyst, minimal ventriculomegaly, thickened nuchal fold) and 71 (4.3%) cases of aneuploidy or other genetic diseases. There were 893 (54.7%) sonographically diagnosed structural abnormality cases. In this group, postnatal confirmation of the abnormalities was present in 486 cases, resulting in an overall positive predictive rate of 64.9%. This rate ranged from 47.1% for ventricular septal defect cases, to 60.0% for Fallot’s Tetralogy cases to 95% for facial cleft abnormalities. A separate study of 1332 isolated echogenic cardiac focus cases was evaluated, demonstrating no additional risk of aneuploidy for these cases. Conclusions: Meticulous collection of prospective birth defect data serves to provide accurate information for patient counselling. This enables patients to make clear choices for their pregnancy, and in addition serves to pursue academic knowledge, educate clinicians, maintain and improve screening and diagnostic standards, audit antenatal interventions and monitor epidemiological trends. P060 An audit of fetal anomalies detected by ultrasound D. A. Pascall * and D. Churchill† *Walsgrave Hospital, UK and †Good Hope Hospital, UK Objectives: A retrospective audit of the outcome of pregnancies with suspected fetal abnormalities was performed to determine anomaly detection rates, false positives and false negatives rates. A review of the antenatal care of all women who had a fetal abnormality initially diagnosed at birth was also undertaken. Methods: All cases of suspected fetal anomalies during a two year period at a District General Hospital were reviewed. Routine Table 1 Patient # Age G P Week at diagnosis Conception # Fetuses Anomalies Karyotype Outcome 1 37 2 1 15 ICSI Twins BC/BA Hemivertebrae L4, SUA No Evaluation Selective Termination 2 32 1 0 16 ICSI Single Hemivertebrae D8, L1, Mild Pyelectasis 46XY Alive, No Neuro. Deficit 3 34 3 2 23 Sp Single Hemivertebrae D12 46XX Alive, No Neuro. Deficit 4 30 1 0 14 Sp Twins BC/BA Hemivertebrae L2 46XY/46XX Alive, No Neuro. Deficit 5 35 3 0 16 Sp Single Hemivertebrae L5, VSD. Horseshoe Kidney, Anal Fistula 46XX VATER 6 30 1 0 23 Sp Single Hemivertebrae L2, Hydronephrosis, Gastroschisis, IUGR No Evaluation TOP Ultrasound in Obstetrics & Gynecology 2003; 22 (Suppl. 1): 71–175 87