What are the management options for hyperemesis of pregnancy?

Management of Hyperemesis Gravidarum

For hyperemesis gravidarum, a stepwise approach starting with non-pharmacological interventions followed by first-line medications (vitamin B6, ginger, and H1-receptor antagonists) and escalating to IV fluids, electrolyte replacement, and additional antiemetics for severe cases is recommended. 1, 2

Definition and Assessment

• Hyperemesis gravidarum (HG) is an intractable form of nausea and vomiting in pregnancy characterized by persistent vomiting, weight loss ≥5% of pre-pregnancy weight, dehydration, and ketonuria, affecting 0.3-2% of pregnancies 2
• Severity can be assessed using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score to guide management decisions 1
• HG typically begins before week 22 of gestation, with symptoms resolving by week 16 in >50% of patients and by week 20 in 80%, though 10% may experience symptoms throughout pregnancy 2
• Liver function tests should be checked, as approximately 50% of patients will have abnormal AST and ALT levels 2

Non-Pharmacological Management

• Dietary modifications are the initial step, including:
  • Small, frequent, bland meals (e.g., BRAT diet - bananas, rice, applesauce, toast) 1
  • High-protein, low-fat meals 1
  • Avoiding spicy, fatty, acidic, and fried foods 1
  • Identifying and avoiding specific food triggers and strong odors 1
• For patients with adjustable gastric bands, deflation may be necessary to prevent band slippage and nutrient deficiencies 2

First-Line Pharmacological Management

• Vitamin B6 (pyridoxine) 10-25 mg every 8 hours as recommended by ACOG 1
• Ginger 250 mg capsule 4 times daily 1
• H1-receptor antagonists (considered safe first-line therapies):
  • Doxylamine (FDA-approved and ACOG-recommended for persistent NVP) 1
  • Doxylamine and pyridoxine combination (available in 10 mg/10 mg and 20 mg/20 mg combinations) 1
  • Promethazine and dimenhydrinate 1

Management of Moderate to Severe Cases

• Immediate intravenous fluid resuscitation to correct dehydration 2
• Electrolyte replacement with particular attention to potassium and magnesium levels 2
• Thiamine supplementation (vitamin B1) to prevent Wernicke's encephalopathy 2
• Additional antiemetics:
  • Metoclopramide (category A) 3
  • Ondansetron (5-HT3 antagonist) with monitoring for QT interval prolongation, especially in patients with electrolyte abnormalities 2
  • Prochlorperazine (category C) 3
  • Promethazine (category C) 3

Management of Refractory Cases

• Intravenous corticosteroids may be considered, though evidence for their efficacy is mixed 4, 5
• Alternative pharmacotherapeutics for refractory cases:
  • Mirtazapine 4
  • Olanzapine 2, 4
  • Gabapentin 2, 4
  • Prednisolone (category A) 3
• For prolonged cases with ongoing weight loss, consider:
  • Enteral nutrition 4
  • Parenteral nutrition in extreme cases 4

Monitoring and Follow-up

• Regular assessment of hydration status and electrolyte balance 2
• Evaluation of symptom control using PUQE score 2
• Fetal growth monitoring, especially with insufficient gestational weight gain (monthly scans from viability in severe cases) 2
• Monitor for complications including electrolyte imbalances (particularly hypokalemia) 2

Prognosis and Complications

• Untreated HG is associated with low birth weight, small for gestational age infants, premature delivery, and decreased maternal quality of life 2, 6
• Early intervention is crucial to prevent progression from mild nausea and vomiting to hyperemesis gravidarum 2
• Patients should be educated about the high recurrence risk (40-92%) in subsequent pregnancies 2

Special Considerations

• For patients with hyperemesis gravidarum and Bartter syndrome, aim for plasma potassium levels ≥3.0 mmol/L 2
• Persistent liver chemistry abnormalities despite symptom resolution should prompt investigation for another etiology 2
• Multidisciplinary care involving obstetricians, gastroenterologists, and nutritionists may be required for severe cases 2