[Hygroma colli--sonographic indication of fetal chromosome abnormality. A case report].

Transvaginal sonography has been developed as an useful tool to recognize and define structural defects in the first trimester fetus. Fetal cystic hygromas as an manifestation of malformation of the lymphatic system are often the only sign of an severe fetal anomaly. In 70-80% of cases cystic hygroma is associated with a Turner-Syndrome (45,XO). We report a case in which transvaginal sonography has been the only instrumental in the prenatal diagnosis of a nuchal cystic hygroma. Based on this sonographic finding the pregnancy has been terminated. We point to the value of early and subtle ultrasound examination as an excellent method in finding hints for chromosome abnormalities.