Transient osteoporosis of the hip in the first trimester of pregnancy. A case report and review of Japanese literature.

A patient with transient osteoporosis of the hip in her first trimester of pregnancy is reported in this study. Rapid symptomatic improvement after artificial abortion was observed. These findings exclude pressure on the obturator nerve, Sudeck's osteodystrophy, venous obstruction, and excessive demand of proteins and calcium in the etiology of this condition. Rather it is here suggested that chemical or hormonal factors related to pregnancy play an important role in the etiology.