Diagnosis of thanatophoric dwarfism in utero.

A 29-year-old multipara presented at the University Hospital, Kuala Lumpur at 26 weeks gestation. She has had two normal deliveries at this hospital, a girl in 1977 and a boy in 1978. Both children are normal and healthy. In this third pregnancy uterine size was larger than dates and hydramnios was suspected. Sonography confirmed the hydramnios and showed a single foetus with hydrocephalus and micromelia. BPD was 83 mm at 26 weeks and 114 mm at 35 weeks gestation by dates. Shortlimbed dwarfism was suspected. Antenatal radiographs and fetography were performed. These showed short curved limb bones, H-shaped vertebral bodies, large head and narrow thorax with short ribs. On the basis of these radiographic features (Fig. 1) an antenatal diagnosis of thanatophoric dwarfism was made. 250 ml of fluid was aspirated from the foetal head by percutaneous needle puncture under ultrasound