Risk factors of perioperative hypoparathyroidism after thyroidectomy: a systematic review and meta-analysis

Perioperative hypoparathyroidism (hypoPT) represents a prevalent complication of thyroid surgery. Reported risk factors remain inconsistent, and identical factors may exert different effects depending on whether hypoPT is defined by serum calcium concentration or parathyroid hormone (PTH) levels. A comprehensive synthesis was undertaken to clarify risk factors for hypoPT under these distinct biochemical definitions.

Three databases (PubMed, Embase, and Scopus) were searched from inception to 2025. Study quality was assessed using the Newcastle-Ottawa scale. Pooled odds ratios (ORs) were calculated to examine associations between risk factors and perioperative hypoPT defined by calcium or PTH. Subgroup analyses were performed according to biochemical definitions, and publication bias was assessed with Begg and Egger tests.

Sixty-four studies reporting 19 risk factors were included. Sex was the most frequently analyzed variable. For hypoPT defined by calcium, significant associations were observed with female sex, parathyroid glands remaining in situ , central neck dissection, lateral neck dissection, malignant pathology, parathyroid autotransplantation, incidental parathyroidectomy, parathyroid tissue in the specimen, and type of surgery (total thyroidectomy vs partial thyroidectomy). Higher postoperative PTH levels acted as a protective factor for calcium-defined hypoPT. For PTH-defined hypoPT, only malignant pathology showed a statistically significant association.

Patients with thyroid cancer undergoing total thyroidectomy with lateral neck dissection are at greatest risk of perioperative hypoparathyroidism. Risk reduction relies on precise intraoperative identification of the parathyroid glands, improved surgical proficiency and awareness, and prompt correction of inadvertent excision.