Treatment of Hyperemesis Gravidarum in Pregnancy
First-line management of hyperemesis gravidarum should include dietary modifications, vitamin B6 supplementation, ginger, and H1-receptor antagonists like doxylamine, followed by more aggressive interventions for refractory cases including IV fluids, additional antiemetics, and possibly corticosteroids. 1
Definition and Epidemiology
- 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 1
- It affects 0.3-2% of pregnancies, compared to normal nausea and vomiting which affects 30-90% of pregnancies 2, 1
- Symptoms typically begin at 4-6 weeks, peak at 8-12 weeks, and resolve by week 16 in >50% of patients and by week 20 in 80% of patients, though 10% may experience symptoms throughout pregnancy 2, 1
Assessment and Diagnosis
- Severity can be quantified using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score, which evaluates duration of nausea, frequency of vomiting, and frequency of retching 2
- Laboratory evaluation should include electrolyte panel, liver function tests (approximately 50% of patients will have abnormal AST and ALT), and urinalysis for ketonuria 1
- Abdominal ultrasonography is important to detect multiple or molar pregnancies and assess fetal growth 1
Treatment Algorithm
Step 1: Non-pharmacological Interventions
- Dietary modifications: small, frequent, bland meals; BRAT diet (bananas, rice, applesauce, toast); high-protein, low-fat meals 2
- Avoid specific food triggers and strong odors 2
- For patients with adjustable gastric bands, deflation may be necessary to prevent band slippage and nutrient deficiencies 2
Step 2: First-line Pharmacological Management
- Vitamin B6 (pyridoxine): 10-25 mg every 8 hours 2, 1
- Ginger: 250-mg capsule 4 times daily 2, 1
- H1-receptor antagonists (considered safe first-line antiemetics):
Step 3: Management of Moderate to Severe Cases
- Intravenous fluid resuscitation to correct dehydration 1, 3
- Electrolyte replacement with particular attention to potassium and magnesium levels 1
- Thiamine supplementation (vitamin B1, 300 mg daily) to prevent Wernicke's encephalopathy 2, 1, 4
- Additional antiemetics:
Step 4: Refractory Cases
- Intravenous corticosteroids (prednisolone, category A) 1, 3
- Consider alternative therapies like olanzapine and gabapentin 1
- Hospitalization for severe cases 5, 6
- Parenteral nutrition may be required in extreme cases 5, 6
Monitoring and Follow-up
- Regular assessment of hydration status and electrolyte balance 1
- Evaluation of symptom control using PUQE score 1
- Monthly fetal growth monitoring scans from viability, especially with insufficient gestational weight gain 2, 1
- Monitor for complications:
Prognosis and Special Considerations
- Untreated hyperemesis gravidarum is associated with low birth weight, small for gestational age infants, and premature delivery 1
- Early intervention is crucial to prevent progression from mild nausea and vomiting to hyperemesis gravidarum 2, 1
- High recurrence risk (40-92%) in subsequent pregnancies 1
- Multidisciplinary care involving obstetricians, gastroenterologists, and nutritionists may be required for severe cases 1
Common Pitfalls and Caveats
- Failure to exclude other causes of nausea and vomiting such as urinary tract infection, thyrotoxicosis, or hepatobiliary disorders 1, 3
- Delaying antiemetic therapy due to unfounded teratogenicity concerns - there are abundant data on the safety of antihistamines, phenothiazines, and metoclopramide in early pregnancy 4
- Overlooking thiamine supplementation, which is critical to prevent Wernicke's encephalopathy 2, 1, 4
- Inadequate fluid and electrolyte replacement, which can lead to further complications 1, 6