24–28 August 2008, Chicago, USA Poster abstracts abnormalities were observed. Twin B showed a giant multiseptate cystic mass covering the whole left hemitruncus from the left axilla to the iliac region. Color and pulsed Doppler ultrasound revealed no blood flow within the mass. A detailed cerebral sonographic exam- ination was performed and it revealed a ventricular asymmetry (left atrial width 11.5 mm) and head circumference on 90 th percentile. Posterior fossa and cerebellum appeared normal. An increase on head circumference (> 98 th percentile) was noted at 30 weeks of ges- tation, with a hemispheric asymmetry, diffusely dystrophic cerebral structures, large dilatation mainly at posterior horn of left lateral ventricle and midline shift. Abdominal cystic mass seemed similar to previous study. An elective caesarean section was carried out at 36 weeks of gestation. Twin B weighed 2434-g and APGAR scores were 10 and 10 at 1 and 5 min. There were macrocephaly and a 10 cm diameter purple colored cystic mass in the left hemiabdomen. Postnatal Magnetic Resonance imaging showed findings consistent with hemimegalencephaly and abdominal lymphangioma. Hemimegalencephaly and lymphangiomatous cyst are hamartomas. Hemimegalencephaly is a rare congenital disorder and its prenatal diagnosis is exceptional due to insults probably occurs during the second trimester of pregnancy. There are an isolated form and a syndromic form, in which cutaneous disorders are associated. Postnatal MR is the imagining modality of choise. P37.12 Twins with one face, four arms and four legs in Virtual Reality C. M. Verwoerd-Dikkeboom 1 , A. H. J. Koning 2 , M. Rousian 1 , M. Husen 1 , N. Exalto 1 , E. A. P. Steegers 1 1 Department of Obstetrics and Gynaecology, ErasmusMC, University Medical Centre, Rotterdam, Netherlands, 2 Department of Bioinformatics, ErasmusMC, University Medical Centre, Rotterdam, Netherlands Objective: In this case report we demonstrate the additional value of a virtual reality system in the evaluation of a rare case of conjoined twins at 13 weeks of gestational age. Case report: At 13 weeks of gestational age a 28-year old G2P1 was diagnosed with conjoined twins on routine 2D ultrasound examination. Additional 3D ultrasound revealed fusion of the head, thorax and part of the abdomen. Two heartbeats, one large stomach, 4 arms and 4 legs were seen. The placenta and umbilical cord were shared. These 3D images were also visualized as three-dimensional ‘‘holograms’’ in the I-Space, a virtual reality system that provides depth perception and interaction with the volume in an intuitive manner. In the I-Space the diagnosis of cephalothoracopagus was confirmed. Only one face could be recognized. The pregnancy was terminated using misoprostol and intact twins were born. The parents did not allow any further examinations. Discussion: Conjoined twins occur once in every 100 sets of monozygotic twins. This means once in every 50,000 gestations or once in every 250,000 live births. In 1 out of 58 sets of conjoined twins the diagnosis is a cephalothoracopagus. In this very rare condition the head and thorax are fused, but spine, limbs and pelves are separate. They are also named Janiceps twins, after the two-faced Roman god Janus. Janiceps twins can be either dissymmetrical (two faces are identical on opposite sides of the head) or monosymmetrical (one ‘normal’ face and a second reduced face). In our case, on 2D and 3D ultrasound examination one face could be recognized. The back part of the head could not be visualized and thus definite diagnosis was not possible. The I- Space allowed detailed evaluation of the anatomical structures and intuitive orientation of the dataset. Using this innovative technique it became clear that only one face was present. The diagnosis was therefore a cephalothoracopagus janiceps monosymmetros, which was confirmed post-partum. P38: SECOND AND THIRD TRIMESTER MALFORMATIONS II P38.01 Complete pelvic evisceration and renal hydronephrosis complicating fetal gastroschisis V. Sachar , A. Oto, L. M. DiGiovanni, M. Ismail, H. Kay Maternal Fetal Medicine, University of Chicago, Chicago, United States Gastroschisis is a rare congenital anomaly which involves a full- thickness abdominal wall defect that permits the protrusion of fetal bowel and other abdominal contents into the amniotic cavity. The most common organs to eviscerate are the stomach and the bowel. We report the first case of antenatally detected fetal gastroschisis complicated by renal hydronephrosis, as well as bowel, bladder, and uterus evisceration. A 17 yo primigravida was referred for tertiary assessment and management of her pregnancy following diagnosis of gastroschisis. Her initial presentation at our institution was at 20 wks, where the diagnosis of gastroschisis was confirmed. The remainder of the anatomical survey was normal. Development of FGR prompted frequent sonographic assessment of fetal status, however dopplers remained normal throughout the pregnancy. At her 30 wk sonogram, fetal bladder evisceration was noted as well as fetal right sided hydronephrosis. The bladder gradually enlarged to 45 × 48 × 53 mm with progressive hydronephrosis and oligohydramnios. Consultation with pediatric urology was undertaken, and MRI was ordered for further evaluation of the renal system. The MRI confirmed the above findings but also demonstrated uterine evisceration. A delivery plan for cesarean section was made to preserve the integrity of the eviscerated bladder and uterus. At 37 wks a cesarean section was performed secondary to non-reasurring fetal status; fetal weight 2270g Apgars 8, 9 with small, large bowel, uterus, bladder, fallopian tubes and ovaries all eviscerated. The infant underwent a staged repair with silo. During the repair, the bladder had to be dissected off of the abdominal wall to allow retroperitoneal placement. The nenonate was discharged home in 25 days in good condition. VCUG at the 6 month follow up confirmed normal neonatal renal function. In this case the finding of gastroschisis complicated by complete pelvic evisceration and hydronephrosis was not associated with poor fetal outcome. P38.02 Ultrasound findings of junctional epidermolysis bullosa, case report M. Tulbah 1 , R. A. Damadi 2 , W. Kurdi 1 1 OB GYN, Maternal Fetal Medicine Unit, King Faisal Specialist Hospital, Riyadh, Saudi Arabia, 2 OB GYN, Fetal Ultrasound Unit, King Faisal Specialist Hospital, Riyadh, Saudi Arabia Case report: A 21 years old lady, G2 P1, with positive history of consanguinity, first pregnancy was followed in a peripheral hospital, was complicated with polyhydraminous, there was large areas of skin absence in the baby after delivery mainly in distal areas of the limbs, and large defect in the scalp temporal areas, no skin vesicles, baby died on day 6 due to sepsis, did not pass meconium and there was no gas in the intestine. There was no further workup due to lack of facilities. Patient was referred to our hospital at 15 weeks were an early anatomy scan and the 22 weeks scan were both normal. Patient had few antenatal visits as she was from a far area. At 35 weeks she was seen in the clinic, the ultrasound findings were polyhydraminos, dilated fetal stomach, In the lower limbs there was an abrupt defect of the soft tissue bilaterally below the knee, with normal feet, the upper limbs were normal. (Image 1) 3D ultrasound showed a very interesting pictures of there findings. (Image 2) Patient delivered at 36 weeks the postnatal findings were compatible with the ultrasound findings. (Image 3). X ray showed dilated stomach Ultrasound in Obstetrics & Gynecology 2008; 32: 398–466 441