16th World Congress on Ultrasound in Obstetrics and Gynecology Poster abstracts P01.41 Ultrasonographic findings in complete trisomy 9: report of two cases E. Antol´ ın , O. Mart´ ınez, M. Ruiz Hospital de la Zarzuela, Spain Trisomy 9 in complete non-mosaic state is an uncommon chromo- somal abnormality. Because of its high intrauterine lethality rate, mainly in the first trimester of pregnancy, only a few cases regard- ing sonographic findings have been reported. Ultrasound features leading to the diagnosis of this chromosomal abnormality include central nervous system, craniofacial, cardiovascular, genitourinary and musculoskeletal malformations as well as early intrauterine growth restriction and oligo-anhydramnios. We report two cases of complete trisomy 9 detected in the early second trimester. Both of them had a normal nuchal translucency (NT) at 11 week scan. In case 1, amniocentesis was performed because the risk for trisomy 18 at the combined test was greater than 1/50 (free BhCG: 0.09 MoMs; PaPP-A: 0.23 MoMs) and in case 2 because of advanced maternal age. Ultrasound examination before amniocentesis at 16 and 14 weeks of gestation, respectively, revealed similar findings (case 1: absent cerebellar vermis, ventriculomegaly, dysmorphic face and dysplastic kidneys; case 2: oligohydramnios, absent cerebel- lar vermis, hypotelorism, complete atrioventricular septal defect, echogenic bowel, echogenic kidneys, mild generalized subcutaneous edema and ductus venosus pulsatility index (DVPI) greater than 95th centile). Quantitative fluorescent polymerase chain reaction (QF-PCR) for chromosomes 21, 13, 18, X and Y was indicated with normal results in both of the cases but diagnosis of trisomy 9 was made by conventional cytogenetic analysis of amniotic fluid samples. An intrauterine fetal death was diagnosed in case 1; in case 2 parents opted for termination of pregnancy. Because the sono- graphic findings of trisomy 9 are similar to those of trisomy 18 and 13, in spite of its very rare incidence, diagnosis of trisomy 9 should be considered when QF-PCR studies are performed in these fetuses. P01.42 Likelihood ratio for trisomy 21 in fetuses with abnormal nuchal translucency measurement at the 11–14-week scan C. G. V. Murta 1,2 , L. C. Fran¸ ca 2 1 Hospital of Policia Militar, ES, Brazil, 2 Federal University of Espirito Santo, UFES, Brazil Objectives: To determine the likelihood ratio for trisomy 21 in fetuses with abnormal nuchal translucency measurement at the 11 to 13 + 6 week scan. Methods: Nuchal translucency thickness was prospectively measured in 3238 fetuses. Pregnancy’s follow-up was carried out to determine the presence of Down syndrome. Two experienced sonographers performed transabdominal and/or transvaginal scans using high- resolution ultrasound equipment. The ultrasound examinations included assessment of fetal number and viability, NT measurement and fetal anatomy survey. Down syndrome risk was calculated using the specialized computer program provided by the Fetal Medicine Foundation. For statistical analysis the T student test, analysis of variance and linear regression were predominantly used. The sensitivity, specificity, positive and negative predictive values, false-positive were calculated. The likelihood ratio for trisomy 21 in fetuses with NT measurement was above the 95th percentile. Results: Twenty-three Down syndrome fetuses were detected. Of this group, 16 fetuses had abnormal NT thickness (sensitivity 69.6%, specificity 97.8%; positive and negative predictive values 18.6% and 99.8%, respectively; and positive and negative likelihood ratios 31.9 and 0.3, respectively). Conclusion: Enlarged nuchal translucency is an useful marker of trisomy 21 in the first-trimester ultrasound screening. P01.43 Prenatal diagnosis of a case with EMANUEL syndrome (supernumary der (22) syndrome) M. A. Guven 1 , G. Ceylaner 2 , S. Ceylaner 2 , A. Coskun 1 1 Department of Obstetrics and Gynecology, Khramanmaras Sutcu Imam University, Faculty of Medicine, Turkey, 2 Zekai Tahir burak Women’s Health Education and Investigation Hospital, Department of Genetics, Ankara, Turkey Emanuel syndrome is caused by a t (11; 22) (q23; q11.2) translo- cation, the only known recurrent, non-Robertsonian, constitutional translocation in humans. Carriers of the balanced constitutional t (11; 22) translocation are phenotypically normal but are at risk of having progeny with supernumerary der (22)t (11; 22) syndrome as a result of malsegregation of the der (22). Individuals with der (22) syndrome have a distinct phenotype consisting of severe men- tal retardation, preauricular tag or sinus, ear anomalies, cleft or high-arched palate, micrognathia, microcephaly, kidney abnormali- ties, heart defects. A 23-year-old pregnant woman gravida 2 para 0 attended the antenatal clinic of Kahramanmaras Sutcu Imam Univer- sity for a routine anomaly scan at 22 weeks’ gestation. Parents were not relatives. Obstetric ultrasound demonstrated partial cerabellar vermian agenesis and posterior fossa dilatation in cranium with the diagnosis of partial Dandy-Walker Malformation. Additionally, fetal echocardiography showed pulmonary stenosis, perimebrane- ous VSD, posterior position of pulmonary artery according to the aorta and overring of the aorta supported the diagnosis of Tetralogy of Fallot. After a detailed genetic counselling, cordocenthesis was performed at 23 weeks’ gestation and a supernumerary marker chro- mosome was detected. Subsequently, parental chromosome analysis presented maternal translocation, 46,XX, t (11; 22) (q23; q11.2) and fetus was diagnosed as 47,XX,+der (22)t (11; 22) by using parental karyotype results. Pregnancy was terminated and low set small ear, cleft or high-arched palate, micrognathia, microcephaly was observed in addition to the above ultrasonographic findings. As the prenatal diagnosis of Emanuel syndrome was rarely reported in the literature and because of this event is an example of realy an interesting chromosomal rearrangement, this case was decided to report here. P01.44 First-trimester fetal heart rate and Down syndrome screening I. Kalelioglu , R. Has, S. Aydin, H. Ermis, A. Yildirim, L. Ibrahimoglu, A. Yuksel Istanbul University, Turkey Objective: To determine the feasibility of using FHR in prediction of Down syndrome. Method: Mom values of FHR at 11–14 weeks of gestation in 813 normal fetuses were compared to MoM values of 9 fetuses with Down syndrome. A subgroup of 759 normal fetuses which gestational age is calculated with correct LMP with whose mothers has regular menses history was used to establish formula to calculate median values. During the ultrasound examination for measurement of fetal crown-rump length, the fetal heart rate was also recorded by the simultaneous use of M-mode and real-time B-mode imaging to obtain recordings of 10 cardiac cycles; the interval was measured with electronic calipers and the embryonic fetal heart rate was calculated using the software of the ultrasound machine. Result: Linear decreases in FHR were observed with increasing GA and CRL. A linear curve was optimally fitted with the FHR data when regressing by CRL (FHR = 177, 813 − (0.2936 × CRL)). Normal distributions in both groups were showed by Kolmogorov- Smirnov and Shapiro-Wilk’s tests. Mean MoM values were 1.0003 ± 0.05179 and 0.9830 ± 0.04803 for normals and Down syndrome fetuses, respectively. No statistically significant difference was detected between FHR MoM values of normal fetuses and fetuses with Down syndrome. 522 Ultrasound in Obstetrics & Gynecology 2006; 28: 512–614