Pregnancy and lactation-related osteoporosis associating multiple vertebral fragility fractures treated with romosozumab: a case report.

Background: Pregnancy- and lactation-related osteoporosis (PLO) is a rare condition of skeletal fragility affecting women during late pregnancy and early lactation. Patients with PLO who experience multiple, rapid-onset vertebral fractures and develop kyphosis face a poorer prognosis when diagnosis and treatment are delayed. Since there is no standard treatment protocol for patients with PLO, treatment should be individually planned. Recently, romosozumab has been recognized as one of the most effective drugs for treating patients with severe osteoporosis. Because it can dramatically increase bone mineral density (BMD) in a short period in postmenopausal women with osteoporosis, it is useful for treating patients with rapidly progressive osteoporosis at a high risk of fracture. Here, we report a case of PLO associated with multiple vertebral fractures treated with romosozumab. To the best of our knowledge, this is the first report on the use of romosozumab alone for PLO. Case Description: A middle-aged postpartum and lactating woman experienced back pain at 9 months of pregnancy, which worsened after delivery. PLO was diagnosed based on multiple thoracic vertebral and sacral fragility fractures and low BMD. She was treated with romosozumab, and her back pain gradually subsided. After 12 months of romosozumab treatment, her lumbar spine BMD increased by 22.1% from baseline, and no further fractures occurred. Conclusions: Twelve months of romosozumab treatment successfully improved the clinical condition of the patient with severe PLO, resulting in a remarkable increase in BMD.