Calcium homeostasis in a patient with hypoparathyroidism during pregnancy, lactation and menstruation

ObjectiveTo report a case of hypoparathyroidism post-thyroidectomy in a woman with variable calcium requirements during pregnancyMethodsClinical and biochemical data were reviewed, and management of hypocalcaemia is described.ResultsWe report on a 37-year-old pregnant woman with hypoparathyroidism post-thyroidectomy who had been on stable doses of calcitriol and calcium for many years. During her first pregnancy, her calcium requirement increased; however, she was found to be hypercalcaemic peripartum. She resumed menstruation while breastfeeding and experienced hypocalcaemic symptoms around menstruation. Her second pregnancy was complicated by profound symptomatic hypocalcaemia at 9 weeks of pregnancy, coinciding with the cessation of breastfeeding and mimicking ‘hungry bone syndrome’. This has not been described previously.ConclusionOur case confirms that the calcium requirement is increased during early pregnancy and after weaning but is decreased during late pregnancy, puerperium and lactation. This case highlights the importance of close follow-up of calcium levels in women with hypoparathyroidism during gestation and lactation, especially for consecutive pregnancies.