What are the treatment options for nausea and vomiting in pregnancy?

Treatment of Nausea and Vomiting in Pregnancy

Early treatment of nausea and vomiting of pregnancy with a stepwise approach is essential to reduce progression to hyperemesis gravidarum, beginning with lifestyle modifications and vitamin B6, followed by medication combinations for moderate to severe symptoms. 1, 2

Assessment of Severity

• The Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score helps quantify severity, categorizing symptoms as mild (≤6), moderate (7-12), or severe (≥13) 2
• Hyperemesis gravidarum affects 0.35-2% of pregnancies and is characterized by persistent vomiting, weight loss >5% of prepregnancy weight, dehydration, and ketonuria 1, 2
• Nausea and vomiting typically begins at 4-6 weeks, peaks at 8-12 weeks, and subsides by week 20 in most women 1, 3

First-Line Interventions (Mild Symptoms)

• Dietary modifications are the initial approach:

  • Small, frequent, bland meals (e.g., BRAT diet - bananas, rice, applesauce, toast) 2, 3
  • High-protein, low-fat meals 2
  • Avoiding spicy, fatty, acidic, and fried foods 2, 4
  • Separating solid and liquid intake 3
  • Avoiding an empty stomach 3

• Non-prescription supplements:

  • Ginger 250 mg capsules four times daily 2, 3
  • Vitamin B6 (pyridoxine) 10-25 mg every 8 hours (up to 40-60 mg/day) 2, 3, 4

Second-Line Interventions (Persistent or Moderate Symptoms)

• Doxylamine and pyridoxine combination is FDA-approved for moderate symptoms 2, 4
• Other H1-receptor antagonists if doxylamine is unavailable:
  • Promethazine (FDA-approved for nausea and vomiting in pregnancy) 2, 5
  • Dimenhydrinate 2
• Metoclopramide 5-10 mg orally every 6-8 hours has been shown to be safe and effective 3

Third-Line Interventions (Severe Symptoms or Hyperemesis Gravidarum)

• Ondansetron can be considered when other treatments fail, though it carries a small risk of cleft palate (0.03% absolute increase) and ventricular septal defects (0.3% absolute increase) 3
• Intravenous hydration and correction of electrolyte abnormalities 1, 3
• Thiamine supplementation to prevent Wernicke's encephalopathy 1, 3
• Intravenous glucocorticoids may be required in severe cases, but should be avoided before 10 weeks gestation due to increased risk of oral clefts 1, 2, 3

Important Clinical Considerations

• Early intervention is crucial to prevent progression to hyperemesis gravidarum 1, 2
• Liver enzyme abnormalities occur in approximately 50% of hyperemesis gravidarum cases but rarely exceed 1,000 IU/mL and typically resolve with hydration 1
• Persistent liver chemistry abnormalities despite symptom resolution should prompt investigation for another etiology 1
• A multidisciplinary approach involving obstetrics and gastroenterology may be beneficial for patients with moderate to severe symptoms 3
• For pregnant patients with complex conditions, coordination of care by a multidisciplinary team at a tertiary care center is recommended 1

Treatment Algorithm

1. Start with dietary modifications and vitamin B6 ± ginger for mild symptoms 2, 3
2. If symptoms persist or worsen, add doxylamine (or alternative antihistamine like promethazine) 2, 5
3. For moderate symptoms unresponsive to above, add metoclopramide 3
4. For severe symptoms or hyperemesis gravidarum, consider ondansetron, IV hydration, and possibly IV glucocorticoids 1, 2, 3
5. Throughout treatment, continuously reassess using the PUQE score and adjust therapy accordingly 2