Prenatal diagnosis and obstetric management of Larsen's syndrome in a patient with an unrecognized family history of the disease.

We report the third case of a prenatal diagnosis of Larsen's syndrome, which is the first report affecting both a 37-year-old primiparous caucasian woman and her fetus not considered to have Larsen's syndrome until the finding of bilateral clubfeet was demonstrated on screening ultrasound at 23 weeks of gestation. History and physical examination of the pregnant woman revealed severe impairment in the mobility of hip, elbow and knee joints starting in early childhood. Additional findings were spatulate thumbs and a flat nasal bridge. The mother of the pregnant woman demonstrated similar joint symptoms. The differential diagnosis of Larsen's syndrome was considered for the first time in both women. The patient wished to terminate her pregnancy, as the potential early onset of the same disorder was suggested by the finding of clubfeet. An intraamniotic instillation of ethacridinic acid was performed. On pathological examination including radiography of the male stillborn, various anomalies of the face, and upper and lower extremities were demonstrated compatible with Larsen's syndrome.