Pathomorphological findings of a prenatally diagnosed thanatophoric dwarf.

A case of prenatally diagnosed thanatophoric dysplasia is presented. Other syndromes accompanied by chondrodysplastic tetramicromelia were excluded and diagnosis was based on the narrow thorax, secondary pulmonary hypoplasia and macrocephaly detected by ultrasound and on radiological findings of disturbances of bone formation. At the mother's request labour was induced and radiological, anatomic and histological examination of the newborn confirmed the prenatal diagnosis. By electron microscopy, large conspicuous, homogeneous intracytoplasmic, usually single vacuoles were found in virtually every chondrocyte. Attention is focused on the significant hydramnion which led to the suspicion of fetal malformation. The importance of routine ultrasound screening in pregnancy is emphasised, since such malformations can be detected as early as the midtrimester pregnancy. The use of such methods ensures better maternal care.