Pregnancy Complicated By Hypocalciuric Hypercalcemia

Presentation Number: MON 307
Date of Presentation: April 3rd, 2017

Stephen G Rosen*
Pennsylvania Hospital, Philadelphia, PA

Abstract

Background: During pregnancy, total serum calcium decreases secondary to lower serum albumin levels; serum ionized calcium remains unchanged. Serum PTH is normal or suppressed during pregnancy. Serum 1,25-dihydroxyvitamin (1,25D) more than doubles during the first trimester and remains elevated throughout the remainder of pregnancy. Hypercalcemia during pregnancy is uncommon with an incidence of 0.03% of woman of reproductive age. In this case, hypercalcemia was discovered at week 12 of pregnancy. Laboratory testing confirmed the presence of hypocalciuric hypercalcemia.

Clinical case: A 32-year-old woman with no significant past medical history was found to have hypercalcemia during an evaluation of a toenail fungal infection at week 12 of her first pregnancy. She stated that her weight had decreased slightly despite a good appetite. She reported fatigue, insomnia, abdominal bloating, nausea, nocturia, and occasional night sweats. Her only medication was a daily prenatal vitamin. Her family history was positive for kidney stones (father), but negative for hypercalcemia. Physical examination was significant for a heart rate of 119 beats/min and regular and a blood pressure of 110/72 mmHg. Her weight was 66.7 kg. Her thyroid gland was normal sized. There was no lymphadenopathy. Cardiopulmonary examination was normal. There was no peripheral edema. Muscular strength was normal. No tremor was present. Laboratory testing revealed a serum calcium concentration of 10.6 mg/dL with a serum albumin concentration of 4.4 g/dL. Her intact serum PTH concentration was 32 pg/mL (normal range 15-65 pg/mL). Her serum levels of 25-hydroxyvitamin D (25D) and 1,25D were 32.2 ng/mL (normal range 30-100 ng/mL) and 93.8 pg/mL (normal range 19.9-79.3 pg/mL), respectively. Her serum TSH concentration was 2.640 mU/L (normal range 0.450-4.500 mU/L). HerHer thyroid ultrasound demonstrated a normal sized gland with no nodules or parathyroid abnormalities. Her 24-hour urine collection revealed a urine calcium creatinine clearance ratio of 0.003. Her CaSR gene analysis revealed a c.413C>T (p.T138M) variant that has been associated with decreased calcium-sensing receptor response. Her serum calcium concentration increased to a maximum of 11.1 mg/dL at week 23. She was scheduled for full-term delivery on November 10, 2016.

Conclusion: This patient has hypocalciuric hypercalcemia. Her elevated serum 1,25D concentration is consistent with the known increase during pregnancy. In a pregnant woman with hypercalcemia, a 24-hour collection for calcium and creatinine excretion should be performed.

 

Nothing to Disclose: SGR