What is the stepwise approach to managing hyperemesis gravidarum?

Stepwise Management of Hyperemesis Gravidarum

The stepwise approach to hyperemesis gravidarum begins with early intervention using dietary modifications and vitamin B6 with doxylamine, followed by more aggressive antiemetics, IV hydration, and nutritional support for refractory cases. 1

Definition and Diagnosis

Hyperemesis gravidarum (HG) is characterized by:

• Persistent vomiting with weight loss ≥5% of prepregnancy body weight
• Dehydration and ketonuria
• Affects 0.3-2% of pregnancies
• Typically begins in first trimester, peaks at 8-12 weeks
• Resolves by week 20 in 80% of cases, but persists throughout pregnancy in 10% 1

Laboratory findings:

• Abnormal liver enzymes in ~50% of cases (rarely >1,000 U/L)
• ALT typically higher than AST
• Jaundice is rare
• Electrolyte imbalances 1

Risk Factors and Assessment

Risk factors include:

• Prior history of HG
• Hyperthyroid disorders
• Elevated hCG and estrogen levels
• Previous molar pregnancy
• Pre-existing conditions (diabetes, asthma)
• Singleton female pregnancies
• Multiple male fetuses 1

Severity assessment:

• Use Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score:
  • Score ≤6: Mild
  • Score 7-12: Moderate
  • Score ≥13: Severe 1

Stepwise Management Approach

Step 1: Non-pharmacological Interventions

• Dietary modifications:
  • Small, frequent, bland meals (BRAT diet: bananas, rice, applesauce, toast)
  • High-protein, low-fat meals
  • Avoid spicy, fatty, acidic, and fried foods
  • Identify and avoid specific triggers and strong odors 1
• Emotional support and psychological counseling 2

Step 2: First-line Pharmacotherapy

• Vitamin B6 (pyridoxine) 10-25 mg every 8 hours
• Doxylamine 10-20 mg combined with pyridoxine 10-20 mg
• Ginger 250 mg capsules four times daily 1

Step 3: Additional Antiemetics (if symptoms persist)

• H1-receptor antagonists:
  • Promethazine
  • Dimenhydrinate 1
• Dopamine antagonists:
  • Metoclopramide (category A)
  • Prochlorperazine (category C) 2
• Serotonin antagonists:
  • Ondansetron (category B1) 2

Step 4: Management of Moderate to Severe HG

• IV fluid rehydration and electrolyte correction
• Thiamine supplementation to prevent Wernicke's encephalopathy
• Correction of electrolyte abnormalities
• Nutritional support 1

Step 5: Refractory Cases

• Corticosteroids (prednisolone, category A)
• Alternative pharmacotherapeutics:
  • Mirtazapine
  • Olanzapine
  • Gabapentin 3, 4
• Enteral or parenteral nutrition for prolonged cases with ongoing weight loss 3

Important Considerations

• Early intervention is crucial to prevent progression to severe HG 1
• Persistent liver chemistry abnormalities despite symptom resolution should prompt investigation for another etiology 1
• Hyperemesis gravidarum in pregnant women with Bartter syndrome requires special attention due to dangerous electrolyte disturbances 1
• HG is associated with higher risk of low birth weight, small for gestational age, and premature delivery 1
• Recurrence risk is high in subsequent pregnancies 1

Monitoring and Follow-up

• Regular assessment of hydration status
• Monitor weight and nutritional status
• Check for ketonuria
• Evaluate electrolyte levels
• For hospitalized patients, the goal is resumption of oral intake to maintain hydration and nutrition 3

By following this stepwise approach, most cases of hyperemesis gravidarum can be effectively managed to reduce maternal morbidity and improve quality of life during pregnancy.