Disorders of bone and mineral metabolism in pregnancy and lactation: A case based clinical review

Bone and mineral metabolism in the human body undergoes significant adaptations during pregnancy and lactation to meet the physiological demands of both the mother and fetus. The growing fetus requires approximately 30 g of calcium, with 80% of this transferred from the mother during the third trimester. These adaptations involve complex hormonal changes, such as increased parathyroid hormone-related peptide (PTHrP) and 1,25-dihydroxyvitamin D, ensuring the mother maintains calcium balance despite fetal demands. However, these changes can also exacerbate pre-existing metabolic bone disorders, presenting unique challenges during pregnancy. This narrative review, framed around illustrative case examples, focuses on the management of metabolic bone disorders in pregnancy. Relevant case studies of hypercalcemia, hypocalcemia, hypophosphatemia, and osteoporosis and chronic kidney disease mineral bone disorder are reviewed to illustrate the biochemical changes, clinical implications, and therapeutic strategies available during pregnancy and lactation. We analyze literature from case reports and existing guidelines to provide practical clinical recommendations. The review highlights critical pregnancy-related metabolic adaptations, such as increased intestinal calcium absorption and skeletal resorption. Disorders like primary hyperparathyroidism (PHPT) and familial hypocalciuric hypercalcemia present significant maternal and fetal risks, including miscarriage, growth restriction, and neonatal complications. Early identification and tailored treatment, including hydration, parathyroidectomy, and vitamin D supplementation, mitigate these risks, with surgical interventions in PHPT improving pregnancy outcomes compared to conservative management. Management of metabolic bone disorders during pregnancy and lactation requires a nuanced approach to meet the dual needs of the mother and fetus.