7–11 October 2007, Florence, Italy Poster abstracts ultrasound and MRI defined further enlargment of ventricular width (14 mm) and the absence of parieto-occipital fissure, calcarine fissure and cingulate sulcus. The couple after extensive counseling opted for continuing pregnancy. At the moment the pregnancy is ongoing. Unilateral borderline ventriculomegaly, as an isolated finding, is a common sign during ultrasound scan in midgestation, and reports describe it is as minimally effective on developmental outcome. The control of malformations of cortical development with different sulcal and gyral patterns may be associated with specific diagnoses, and provide accurate parental counseling. P38.08 Microcephaly with simplified gyral pattern: the value of ultrasound and fetal MRI on management A. Lembet 1 , H. Bodur 1 , A. Damlacik 1 , B. Selam 1 , A. Yuksel 2 , U. Ince 1 , A. Sav 3 , G. Malinger 4 1 Acibadem Health Group, Turkey, 2 Istanbul University, Turkey, 3 Marmara University, Turkey, 4 Tel-Aviv University, Israel Microcephaly is usually the product of an underdeveloped brain which can be the result of many factors and diagnosed when the head circumference (HC) measures less than 2–3 standard of deviation (SD) below the mean for gestational age. Subtle degree of maldevelopment including anomalous convolution may accompany this pathology. Malformations due to abnormal proliferation have undergone evolution based on MRI, new genetic information and autopsy findings during the last decade. We report a fetus with microcephaly according to ultrasound and MRI findings. A 29-year- old, G1 P0 woman underwent ultrasound examination at 23 weeks of gestation and a fetus with small HC (-1.8 SD) was observed. The brain was considered normal except for a large subarachnoid space with very narrow lateral ventricles. Fetal karyotype was 46XX, 15p+. The fetal MRI at 26 weeks of gestation showed mild microcephaly (-2 SD) and decreased gyral formation were revealed at 29 weeks. The fetal MRI confirmed decreased gyral formation and abnormal sulcation with a postero frontal gradient (HC<-2 SD) at 31 weeks of gestation. The pons measurement was also small and the frontal sulci were absent including the olfactory sulci. The pregnancy was terminated at 32 weeks of gestation. The autopsy findings revealed signs compatible with delayed neurogenesis and minimal macrogyria (pachygyria). We also detected displastic findings in the pons at nucleus olivia. However histological sections from frontal and parietal lobes with hexalaminar allocortical structures were observed to be normal. Moderate to severe mental retardation accompanies 33–62% of cases with mild and severe microcephaly respectively. It is difficult to counsel those patients especially in the absence of other intracranial pathologies. Fetal MRI was used as an adjunctive diagnostic tool and as it revealed an abnormal sulcation and simplified/delayed gyral pattern, decision making process regarding the termination of pregnancy was facilitated. P38.09 Prenatal diagnosis of intracraneal calcifications M. Echevarria , S. Fournier, A. Mu ˜ noz, E. Scazzocchio, M. Torrents, B. Serra Institut Universitari Dexeus, Spain We report a case of an uneventful pregnancy in a 33-year- old gravida 1, para 0 until the 37 th week scan where multiple periventricular and thalami calcifications were diagnosed, all the serological investigations for TORCH were negative. A female newborn was delivered by C-section at 37 weeks’ gestation and the prenatal findings were confirmed by cerebral CT. At three months of life, the Interferon-Alpha in the CSF was found to be elevated and the diagnosis of Aicardi-Gouti` eres syndrome was made. After progressive encephalopathy the girl died at seven months of age. Aicardi-Gouti` eres syndrome (AGS) is a rare autosomal recessive disorder usually diagnosed in the first year of life. AGS is characterized by microcephaly, bilateral basal ganglia calcifications, cerebral white matter abnormalities, cerebral atrophy and chronic CSF lymphocytosis. AGS is progressive, leading to death within the first years of life. P38.10 A case of Meckel – Gruber syndrome diagnosed by ultrasonography at 14 weeks’ gestation S. J. Shin , E. H. Ahn, M. J. Moon, S. H. Kang, S. W. Chang College of Medicine, Pochon Cha University, Republic of Korea The Meckel-Gruber syndrome (MKS) is a rare autosomal recessive disorder that is characterized by typical sonographical findings: occipital encephalocele, postaxial polydactyly and cystic enlargement of the kidneys. Its recurrence risk of 25% demands an exact diagnosis. Although a confident diagnosis is possible only when the syndrome recurs in subsequent pregnancies, the Meckel – Gruber syndrome can usually be suggested on the basis of characteristic pathologic findings and a normal karyotype. This emphasizes the importance of prenatal sonography and a careful postmortem examination to establish the correct diagnosis. Case: A 31-year-old patient was referred from her obstetrician following an ultrasound diagnosis (transabdominal) of occipital bone defect with encephalocele at the 14 th gestational week. She had no consanguinity with her husband. The first pregnancy was interrupted at 20 weeks d/t PPROM, In her second pregnancy she gave birth to a healthy newborn (G 5 P 1 L 1 D 0 A 3). No history of her family had a previous pregnancy with a malformed fetus. This case report is consistent with other reports, that for the diagnosis of Meckel – Gruber Syndrome, the presence of an encephalocele, bilateral polycystic kidneys, and polydactyly are adequate. The Meckel – Gruber syndrome can be confidently detected and diagnosed by sonography at the 14 th gestational week. Later in the pregnancy, severe oligohydramnion makes it more difficult to establish the diagnosis by ultrasound alone. With the present high resolution ultrasound machines it is possible to diagnose Meckel – Gruber Syndrome in the very early second trimester. In cases with Meckel – Gruber Syndrome, parents should be counseled for their further pregnancy, that they have a risk of 25% recurrence, due to its autosomal recessive transmission nature, and an early targeted sonograph should be advised. P38.11 Prenatal diagnosis of multicystic encephalomalacia J. L. Wu , G. P. Yeh, C. T. C. Hsieh, K. H. Fang, H. D. Tsai Changhua Christian Hospital, Taiwan Case 1 was referred to our hospital due to monochorionic twins with one fetal demise at 28 weeks’ gestation. No abnormal sonographic findings could be found in the surviving twin at the time of referral. Decreased fetal movement was noted by the woman 2 weeks later. Two-dimensional sonography revealed ventriculomegaly in the axial plane of the head of the surviving twin. Three-dimensional sonography with multiplanar views showed multiple small sonolucent areas with unusual echogenecities around ventricle of the surviving twin leading to the presumptive diagnosis of periventricular leukomalacia. The MRI confirmed the diagnosis of multicystic encephalomalacia. Finally, she decided to termination of the pregnancy after feticide. Case 2 came for the first ultrasound at 10 weeks. The survey of the fetus did not reveal any abnormality. Her maternal serum screen was done at 16 weeks and was below screen cut off for Down syndrome. Amniocentesis was performed. Karyotype was 46,XX. Target ultrasound examination was done at 20 weeks’ gestation. Morphologic appearance was normal except Ultrasound in Obstetrics & Gynecology 2007; 30: 547–653 595