Transient osteoporosis of hip in pregnancy.

Transient osteoporosis in pregnancy is a relatively rare disorder characterized by disabling pain in the hip without prior trauma and by striking radiographic evidence of osteopenia that is limited to the hip. Clinical and radiographic findings regress spontaneously within months after pregnancy and without late sequelae. In this study, we report on a case of a 28-yr-old Caucasian woman who suffered from transient osteoporosis during pregnancy. Nine months later, the patient was asymptomatic and there was resolution of the bone marrow edema pattern seen on the initial magnetic resonance imaging scan of her hip. Follow-up bone densitometry at 1 yr revealed a dramatic increase (12.3%) in bone mineral density of the symptomatic hip. We review the literature and discuss possible mechanisms involved in the pathogenesis of transient osteoporosis in pregnancy.