Long‐Term Sequential Therapy for Pregnancy‐ and Lactation‐Associated Osteoporosis With Multiple Vertebral Fractures: A Case Report of Over 5 Years

Background Pregnancy‐ and lactation‐associated osteoporosis (PLO) is a rare condition that may cause multiple vertebral fractures during late pregnancy or the postpartum period. Evidence regarding treatment strategies remains limited, particularly regarding long‐term outcomes of sequential regimens combining anabolic and antiresorptive therapies. Case Presentation A 37‐year‐old woman developed low back pain 3 months postpartum and was diagnosed with PLO accompanied by multiple acute and chronic vertebral fractures. Breastfeeding was discontinued, and initial treatment with vitamin D analogs and bisphosphonate therapy was selected based on clinical and patient‐specific considerations, including documented efficacy in PLO, the absence of reproductive safety concerns, and patient preferences. Despite early improvement, lumbar spine Z‐score remained persistently low at −3.0, and therapy was sequentially transitioned to daily teriparatide for 2 years, romosozumab for 1 year, and denosumab for maintenance. Over 5 years and 7 months, lumbar spine and femoral neck bone mineral density increased by 53.4% and 26.1%, respectively. No new fractures occurred, and serial bone turnover markers demonstrated appropriate anabolic and antiresorptive responses at each phase of therapy. Conclusion This case highlights a successful long‐term sequential treatment strategy for PLO involving bisphosphonate, teriparatide, romosozumab, and denosumab in a patient without desire for further pregnancy, without reproductive safety constraints. The individualized sequential approach developed through patient education and shared decision‐making may help achieve sustained improvements in bone mineral density and prevent refracture in patients at very high fracture risk, particularly when an anabolic‐first strategy is not initially feasible.