What are the treatment options for hyperemesis gravidarum?

Treatment Options for Hyperemesis Gravidarum

The treatment of hyperemesis gravidarum requires a stepwise approach beginning with diet and lifestyle modifications, followed by vitamin B6 with doxylamine, and progressing to more potent antiemetics such as ondansetron, metoclopramide, and promethazine for moderate to severe cases, with intravenous glucocorticoids reserved for refractory cases. 1

Definition and Clinical Presentation

Hyperemesis gravidarum (HG) is an intractable form of nausea and vomiting in pregnancy that affects 0.3-2% of pregnant women. It is characterized by:

• Persistent vomiting with weight loss ≥5% of prepregnancy body weight
• Dehydration and ketonuria
• Electrolyte imbalances
• Abnormal liver enzymes in approximately 50% of cases (rarely >1,000 IU/mL) 1

HG typically starts before week 22 of gestation, with symptoms resolving in >50% of affected persons by week 16 and in 80% by week 20. However, in 10% of cases, symptoms persist throughout pregnancy and occasionally into the postpartum period. 1

Evaluation

Before initiating treatment, it's essential to:

1. Quantify severity using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score:

   • Mild: ≤6 points
   • Moderate: 7-12 points
   • Severe: ≥13 points 1

2. Exclude other causes of nausea and vomiting:

   • Hyperthyroid disorders
   • Molar pregnancy
   • Gastrointestinal conditions
   • Urinary tract infections 1, 2

3. Assess for signs of:

   • Dehydration (orthostatic hypotension, decreased skin turgor, dry mucous membranes)
   • Malnutrition (weight loss, muscle wasting)
   • Neurologic deficits (neuropathy, vitamin deficiencies) 1

Treatment Algorithm

Step 1: Diet and Lifestyle Modifications

• Small, frequent, bland meals (BRAT diet: bananas, rice, applesauce, toast)
• High-protein, low-fat meals
• Identify and avoid specific triggers (foods with strong odors, activities) 1

Step 2: First-Line Pharmacologic Therapy

• Vitamin B6 (pyridoxine): 10-25 mg every 8 hours
• Ginger: 250 mg capsule 4 times daily
• Doxylamine: 10-20 mg combined with pyridoxine 10-20 mg 1

Step 3: Moderate to Severe Cases (Inadequate Response to First-Line Therapy)

• Intravenous fluid rehydration with correction of electrolyte abnormalities
• Thiamine supplementation (vitamin B1) to prevent Wernicke's encephalopathy 1, 3
• Second-line antiemetics:
  • Ondansetron (Category B1)
  • Metoclopramide (Category A): 10 mg orally or IV every 8 hours
  • Promethazine (Category C): 12.5-25 mg orally, IV, or rectally every 4-6 hours 1, 2

Step 4: Refractory Cases

• Intravenous glucocorticoids (methylprednisolone or hydrocortisone) 1, 2
• Consider mirtazapine for cases not responding to conventional therapy 4

Special Considerations

Hospitalization Criteria

• Inability to maintain adequate hydration
• Electrolyte imbalances
• Weight loss >5% of pre-pregnancy weight
• Ketonuria
• Failed outpatient management 3, 2

Potential Complications if Undertreated

• Wernicke's encephalopathy (thiamine deficiency)
• Central pontine myelinolysis
• Maternal malnutrition
• Low birth weight and premature delivery 3, 5

Monitoring During Treatment

• Weight
• Hydration status
• Electrolytes
• Liver function tests
• Ketones in urine
• Nutritional status 1

Common Pitfalls to Avoid

1. Delayed treatment: Early intervention may prevent progression to severe hyperemesis gravidarum 1
2. Inadequate hydration: IV fluids are essential in moderate to severe cases
3. Omitting thiamine supplementation: Critical to prevent neurological complications
4. Failure to escalate therapy: Stepwise progression through treatment options is necessary for refractory cases
5. Overlooking psychological impact: HG can cause significant psychological distress requiring support 3, 2

By following this structured approach to the management of hyperemesis gravidarum, providers can effectively address this challenging condition while minimizing maternal and fetal complications.