What is the treatment for hypercalcemia in pregnancy?

Management of Hypercalcemia in Pregnancy

Aggressive intravenous hydration with normal saline is the first-line treatment for hypercalcemia in pregnancy, followed by furosemide after adequate volume repletion to enhance calcium excretion. 1, 2

Initial Assessment and Management

• Hypercalcemia during pregnancy is rare but can lead to significant maternal and fetal complications including urolithiasis, pancreatitis, renal insufficiency, preeclampsia, fetal growth restriction, and intrauterine fetal demise 3
• Prompt diagnosis is essential as symptoms can be nonspecific or masked by physiologic changes of pregnancy 4
• Determine severity of hypercalcemia:
  • Moderate: corrected serum calcium approximately 12-13.5 mg/dL 2
  • Severe: corrected serum calcium >13.5 mg/dL 2

Treatment Algorithm

Step 1: Conservative Management (First-Line)

• Vigorous intravenous hydration with normal saline is the cornerstone of treatment to increase renal calcium excretion 2, 5
• Target urine output of at least 100 mL/hour to promote calcium excretion 1
• Monitor fluid status carefully to avoid overhydration, especially in patients with cardiac concerns 2
• Loop diuretics (furosemide) should only be administered after adequate volume repletion to enhance calcium excretion 1, 5
• Avoid calcium-containing medications and supplements 1
• Avoid vitamin D supplements which can worsen hypercalcemia 1
• Normal calcium intake (minimum 1g per day) and a low-sodium diet are recommended for pregnant women with hypercalcemia 6

Step 2: Surgical Management (For Primary Hyperparathyroidism)

• Parathyroidectomy remains the mainstay of treatment for primary hyperparathyroidism with significant hypercalcemia not responding to conservative measures 4
• Surgery should ideally be performed in the second trimester if the patient has not responded to conservative management 3
• Multidisciplinary team approach involving endocrinology, obstetrics, and surgery is essential 3

Step 3: Pharmacological Management (For Refractory Cases)

• Bisphosphonates should be reserved for selected cases of severe, life-threatening hypercalcemia unresponsive to hydration and diuresis 5
• If bisphosphonates are necessary, pamidronate can be considered at doses of 60-90 mg as a single-dose intravenous infusion over 2-24 hours (longer infusions preferred for patients with renal insufficiency) 2
• Caution: Bisphosphonates may cause symptomatic hypocalcemia and should be used with extreme caution 5
• Calcitonin may be considered as a short-term adjunctive therapy for severe hypercalcemia 6

Monitoring

• Regular monitoring of serum calcium, phosphate, and renal function is essential throughout treatment 1
• Monitor fetal growth and well-being with regular ultrasound assessments 3
• During pregnancy, 25(OH) vitamin D levels should be monitored and adjusted 6
• ECG monitoring for changes related to electrolyte disturbances is recommended in severe cases 1

Special Considerations

• Milk-alkali syndrome (from excessive calcium carbonate antacid ingestion) is an uncommon but important cause of hypercalcemia in pregnancy that should be considered 5
• Hypercalcemia may be associated with hypertensive disorders in pregnancy, and young women with unexplained hypertension in early pregnancy should be investigated for hypercalcemia 3
• Calcium supplementation (1.5-2 g elemental calcium/day) is recommended for pregnant women with low calcium intake to reduce the risk of preeclampsia, but should be avoided in those with hypercalcemia 6

Common Pitfalls to Avoid

• Delaying diagnosis due to nonspecific symptoms or lack of routine calcium screening in antenatal care 4
• Administering loop diuretics before adequate hydration, which can worsen dehydration and hypercalcemia 1
• Overaggressive treatment leading to maternal hypocalcemia, which can affect both mother and fetus 5
• Failure to involve a multidisciplinary team in management decisions 3