P25.14: The utility of ultrasound examination in the prenatal diagnosis of a fetus with omfalocele, severe intrauterine growth restriction and mosaic trisomy 18 syndrome: case report

Abstract

Omphalocele is an anterior wall defect at the base of the ombilical cord that consist in the herniation of the abdominal content covered only by the peritoneum. Omphalocele is associated with other anomalies in more than 60% of the cases. The mortality rate is 80% when associated anomalies are present, and it increases almost to 95% when chromosomal and cardiovascular abnormalities are present. To determine wether omphalocele and intrauterine growth restriction (IUGR) are syndromic or non syndromic. A 29 year old, Caucasian woman was reffered for routine prenatal scan. Double test was performed in another clinic and was normal. The couple has a normal general health exam and no known genetic disorders in the family. Ultrasound evaluation revealed severe intrauterine growth restriction (IUGR): 16.4 weeks – biometrical age and 20.1 weeks – cronological age and an omfalocele image of 25 mm at the base of the umbilical cord. Immediate amniocentesis was performed. It revealed the elevation of the AFP 19745 IU/ml in the amniotic fluid (median deviation 11800 IU/ml). FISH analysis showed mosaic trisomy 18. The pregnancy was terminated one week later. Autopsy revealed the ultrasound images. The two major anomalies were diagnosed using 3D US in the second trimester of pregnancy. Amniocentesis showed a mosaic trisomy 18. Further evaluation of both the parents and future pregnancies should be assessed.