Low Bone Mineral Density and Recurrent Fractures During and After Pregnancy: Dilemma of an Overlooked Diagnosis

Background: Decreased bone mineral density (BMD) during pregnancy and lactation are rarely described in literature. We present this case of multiple compression fractures during and after pregnancy, highlighting the diagnostic and therapeutic dilemma of an overlooked diagnosis. Clinical Case: A 23-year-old female without significant past medical history, suffers from an acute onset lower back pain in the third trimester of her first pregnancy. On initial evaluation, this back pain was thought to be musculoskeletal and was dismissed by her medical team. No imaging was ordered throughout the duration of pregnancy, despite the pain remaining unrelenting. On her second day post-partum, she heard a “pop” in her back and fell while holding her newborn. Imaging revealed multiple vertebral compression fractures, in different stages of acuity. Due to debilitating pain, the patient quit breastfeeding and ultimately would never hold her baby again. Her simple activities of daily living were stymied, both as a mother and secretary. It wasn’t long before she couldn’t even fax forms in her office and had to leave work with debility. Traumatized by these life events and continuing to be afflicted by this chronic pain, the patient decided against having any future children. Her compression fractures were managed with different types of analgesics in addition to vitamin D and calcium supplements. At age 53 and 57, BMD scans showed a T-score >1 at both the lumbar spine and total hip. Forearm BMD was not evaluated at these times. At age 58, a CT spine demonstrated new compression fractures at T5-T12 & L1-L5. She subsequently underwent kyphoplasty of T5, T7 and T8. Fortunately, a bone core biopsy of these 3 vertebrae showed no malignant pathology. A follow up CT scan 6 months later showed stable compression fractures, along with multilevel degenerative changes and neural foraminal stenosis. At age 60, the patient would receive L4-L5 trans-foraminal epidural corticosteroid injection and referral to the bone clinic at a tertiary health center. Initial lab work on referral was significant for normal calcium, albumin, parathyroid hormone, vitamin D, kidney function, liver function, serum and urine protein electrophoresis and cross link N-telopeptide. Osteocalcin was low at 3.9 ng/mL (NL 8.8–37.6 ng/mL). Repeat BMD scan showed T-scores of 0.6, 1.1 and -2.6 at her lumbar spine, total hip and distal forearm respectively. Her osteoporosis is currently managed with teriparatide without active issues. Conclusion: This case highlights the rare development of low BMD in pregnant and breastfeeding women, without prior risk factors, jeopardizing future quality of life. The evidence behind the incidence and pathophysiology underlying these changes remains deficient. There remains a dearth of guidelines for definition and treatment of osteoporosis and low BMD in young peripartum women.