Pregnancy-related osteoporotic vertebral compression fractures in two patients treated with low-molecular-weight heparin during pregnancy: case reports.

Pregnancy-related osteoporosis (PRO) is an uncommon metabolic bone disease that can result in vertebral fragility fractures. Here we report two cases of young women who had been previously treated with LMWH-enoxaparin and were diagnosed with PRO with vertebral fragility fractures after delivery. In first case report, a 33-year-old primigravid woman who was treated with 40 mg/day of enoxaparin for eight months to prevent venous thromboembolism was presented. After delivery, Dual energy X ray absorptiometry (DEXA) revealed osteoporosis in lumbar and femoral neck region. In magnetic resonance imaging (MRI), T4-T7 thoracic vertebral height losses were detected. In second case report, a 28-year-old primigravid woman which was treated with 40 mg/day enoxparin from the second month to the birth was presented. Osteoporosis in lumbar region was detected by DEXA. MRI revealed T12-L1 and L5 vertebral height losses. In conclusion, PRO can cause severe low back pain and should be considered in differential diagnosis. A detailed medical history should be essential to detect relationship between LMWH and PRO.