THU473 Acute Hypercalcemia In The Setting Of Acute Fatty Liver Of Pregnancy, A Case Report

Disclosure: M. Ahmad: None. M. Mack: None. A. Arif: None. L.A. Tejada: None. U. Siddiqui: None. Introduction: Hypercalcemia in pregnancy is rare and often goes unrecognized due to the overlapping symptoms of hypercalcemia and pregnancy. The most common cause of hypercalcemia in pregnant patients is primary hyperparathyroidism, with malignancy, milk alkali syndrome and familial hypocalciuric hypercalcemia being less common. Additionally, endogenous PTHrP production by breast and placental tissue have also been described as rare causes of hypercalcemia in pregnancy. We describe an interesting case of severe hypercalcemia in a pregnant woman presenting with acute fatty liver of pregnancy (AFLP) which rapidly corrected after delivery. Case description: The patient was a 32-year-old female with a past medical history of hypothyroidism and type 2 diabetes mellitus who presented to the emergency department at 32 weeks gestation due to four days of nausea, vomiting and epigastric pain. The patient’s vital signs were as follows: blood pressure: elevated to 133/79 mmHg, heart rate: 75 beats per minute, temperature: 36.7 C, and respiratory rate: 12 breaths per minute. On physical exam, the patient had diffuse abdominal tenderness with no vaginal bleeding. The patient’s blood work was significant for: bicarbonate: 17 mmol/L, creatinine: 1.26 mg/dL (baseline 0.7 mg/dL), corrected calcium of 15.1 mg/dL, ALP: 438 IU/L, AST: 653 IU/L, ALT: 666IU/L, total bilirubin: 2.3 mg/dL, INR 1.3, and ammonia: 43 mcmol/L. She was taken to the operating room for emergent cesarian delivery for concerns of AFLP. Further workup of the patient’s hypercalcemia, revealed a low normal PTH level of 11 pg/dL (normal 11-65 mg/dL), PTHrP level of <5 mg/dL, TSH of 1.37 uIU/ml, 25-OH vitamin D 55 ng/ml, and 1,25-OH vitamin D: 20 pg/ml. After delivery, the patient had alleviation of her symptoms and was kept on dextrose 5% with lactated ringers at 100 cc/h for a total of two days and had complete resolution of her hypercalcemia (corrected calcium of 10.2 mg/dL on discharge). The patient follows with endocrinology as an outpatient and since has had normal calcium levels. Discussion: Hypercalcemia in pregnancy is rare, only affecting 0.03% of women in the reproductive age group, with primary hyperparathyroidism being the most common cause. Hypercalcemia in pregnancy can often be missed due to the hemodilution of serum calcium in pregnancy and also the nonspecific symptoms present in pregnant patients. Our case describes a patient presentation of severe hypercalcemia with AFLP, who had rapid correction of her calcium levels after delivery. The exact mechanism of her severe hypercalcemia developed remains unclear, however, given its rapid resolution with delivery of the placenta potential etiologies include the AFLP itself or possibly the placenta contributing to hypercalcemia. Through this case report, we hope to highlight a possible association between AFLP and hypercalcemia. Presentation: Thursday, June 15, 2023