Endocrine Abstracts

Background: Pregnancy and lactation-related osteoporosis can be associated with fractures during the last trimester or early postpartum period. During lactation, a 3–10% bone loss in the lumbar vertebrae has been detected within 3–6 months. When lactation is reduced bone mineral density(BMD) values reach early postpartum levels within 6–18 months. Certain comorbidities, such as hypercalciuria, premature ovarian failure, low body mass index, oligoamenorrhea, severe vitamin D deficiency, low calcium intake, glucocorticoids can trigger fractures. Compression fractures are typically observed in the lower thoracic and lumbar vertebrae. It’s generally self-limiting, but in some cases should be treated.

Case presentation: A 35-year-old woman experienced severe lower back pain in 2018 during the eighth month of her pregnancy. In February 2018, she underwent a C-section delivery and was diagnosed with osteoporosis while being examined for her persistent pain. The patient does not have any known additional medical conditions. The calcium level is 9.6 mg/dl, 25-hydroxyvitamin D is 6 ng/ml, parathyroid hormone is 48.5 pg/ml. In March 2018, BMD showed a Z-score of −2.6 for lumbar vertebrae and −2.5 for total femur. Due to multiple lumbar vertebral fractures, she underwent a kyphoplasty. Vitamin D3 is given 15.000 international unit per week. Lactation period was almost a year. The control BMD in 2022 showed a Z-score of −1.5 for lumbar vertebrae and −1.9 total femur. With the treatment and cessation of lactation, her bone mineral density improved.

Conclusion: Postpartum osteoporosis is a rare condition that affects otherwise healthy women during the postpartum period. The etiology remains poorly understood, but hormonal changes, particularly the abrupt decline in estrogen levels following childbirth, are believed to play a significant role. This case report highlights the importance of considering postpartum osteoporosis in the differential diagnosis of young women presenting with bone pain and fractures shortly after childbirth.