Endocrine Abstracts

A 25-year-old lady with a background of Multiple Endocrine Neoplasia (MEN) type 2 a was referred to the endocrine team during her first pregnancy. She was initially diagnosed with bilateral phaeochromocytomas in Romania in 2018 after presenting with paroxysmal headaches and hypertension, and underwent laparoscopic bilateral adrenalectomies. Subsequently, she was diagnosed with MEN2 a when found to have a RET gene mutation: RET exon 11 C1901 G2a, p.CYs634Tyr. She was the index case in her family. Three months later, she underwent prophylactic total thyroidectomy and total parathyroidectomy. Three other family members have since been confirmed as MEN2a. On referral to the endocrine team, she was 21 weeks pregnant and taking hormone replacement in the form of Hydrocortisone (10, 5, and 5 mg), Fludrocortisone 100 mg od, Levothyroxine 150 mg od, Adcal 1000 mg od, and Calcitriol 0.25 mg od. Our patient became hypercalcaemic in the second trimester. She was advised to stop Calcitriol and adcal. After cessation, she remarkably had normal levels of adjusted calcium for the remainder of her pregnancy, despite low/undetectable levels of both PTH and PTHrP. Literature review states that there is an increase in serum calcitriol levels in the latter half of the pregnancy. The increase in calcitriol can be regulated by other pregnancy hormones, which are normal in hypoparathyroidism, such as prolactin, oestrogen, and placental growth hormone. In case calcitriol dose is not reduced or stopped then in combination with elevated serum levels, there will be an increase in calcium absorption and bone resorption, which result in hypercalcaemia. Calcitriol levels drop during breastfeeding. Her calcium level dropped post-delivery and she was restarted on supplementation. During the last trimester, our patient was diagnosed with pre-eclampsia (PET). Interestingly calcium supplementation in pregnancy may help prevent hypertension; therefore, reducing the chances of PET. Six months post-partum her calcium levels remain in optimal range (low-normal) on calcitriol 0.5 mg od and calcium 1000 mg od. This case teaches us the importance of closely monitoring calcium levels in pregnancy and post partum in patients with hypoparathyroidism.