Pregnancy associated osteoporosis: the familial effect.

ABSTRACT

OBJECTIVE: The etiology and pathogenesis of pregnancy associated osteoporosis is unclear. Whether pregnancy has simply been an aggravating factor or is a direct etiologic cause responsible for severe bone loss needs to be elucidated. METHODS: In order to evaluate the contribution of familial factors to pregnancy osteoporosis, we analyzed the bone mass of 15 relatives of 5 women with pregnancy osteoporosis. Most of the patients suffered from severe back pain associated with vertebral fractures in their first pregnancy. Extensive clinical, laboratory and radiological investigations were performed to exclude secondary causes of osteoporosis. Bone mineral density measurements were performed on 15 first order family members and the results were compared with those of a control group of 20 healthy members of 5 families. RESULTS: Osteoporosis was present in 53% of the relatives of patients with pregnancy osteoporosis and in 15% of the controls (P < 0.05). CONCLUSION: These results highly suggest that some patients with pregnancy associated osteoporosis have a genetic determination of low peak bone mass, and gestation, due to its association with physiological metabolic disturbances, constitutes a risk factor for the development of skeletal fractures in these patients.