What are the management options for vomiting in pregnancy?

Management of Vomiting in Pregnancy

Early treatment of nausea and vomiting of pregnancy with a stepwise approach including dietary modifications, vitamin B6 and doxylamine, and escalating to antiemetics like ondansetron or metoclopramide for moderate to severe cases is recommended to reduce progression to hyperemesis gravidarum. 1

Understanding Nausea and Vomiting in Pregnancy (NVP)

• NVP affects 30-90% of pregnant women, typically beginning at 4-6 weeks, peaking at 8-12 weeks, and subsiding by week 20 1
• Commonly associated with elevated levels of human chorionic gonadotropin, estrogen, and changes in gastrointestinal motility 1
• Progesterone can inhibit GI and small bowel motility, leading to delayed gastric emptying 1
• Severity can be quantified using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score 1

Initial Management: Non-Pharmacological Approaches

Dietary Modifications:

• Eat small, frequent, bland meals 1
• Follow BRAT diet (bananas, rice, applesauce, toast) 1
• Consume high-protein, low-fat meals 1
• Avoid spicy, fatty, acidic, and fried foods 1

Lifestyle Modifications:

• Identify and avoid specific triggers (certain foods with strong odors or activities) 1
• Separate solid and liquid intake to reduce gastric distension 1

Pharmacological Management

First-Line Therapies:

• Ginger (250 mg capsule 4 times daily) 1
• Vitamin B6 (pyridoxine, 10-25 mg every 8 hours) 1
• Doxylamine (an H1-receptor antagonist) - FDA-approved and recommended by ACOG for persistent NVP refractory to non-pharmacologic therapy 1
• Combination of doxylamine and pyridoxine (available in 10 mg/10 mg and 20 mg/20 mg combinations) 1

Second-Line Therapies for Moderate to Severe Cases:

• Promethazine or dimenhydrinate (H1-receptor antagonists) 1
• Metoclopramide 1
• Ondansetron 1
• Intravenous glucocorticoids for severe, refractory cases 1

Management of Hyperemesis Gravidarum (HG)

• HG affects 0.3-2% of pregnant women, characterized by intractable vomiting leading to:
  • Dehydration
  • Weight loss >5% of prepregnancy weight
  • Electrolyte imbalances 1

Evaluation of HG:

• Comprehensive history, including previous pregnancies and pre-existing conditions 1
• Physical examination focusing on signs of dehydration and malnutrition 1
• Laboratory evaluation for dehydration, nutritional deficiencies, and electrolyte imbalances 1

Treatment of HG:

• Hospitalization may be required 1
• Intravenous hydration and electrolyte replacement 1
• Thiamine supplementation (300 mg daily with vitamin B compound) to prevent Wernicke's encephalopathy 1
• More aggressive antiemetic therapy 1
• Nutritional support as needed 1

Special Considerations

• Early intervention is crucial as NVP can progress to HG if untreated 1, 2
• For pregnant women with history of bariatric surgery and vomiting, adjustable gastric bands should be deflated to prevent band slippage and nutrient deficiencies 1
• Prolonged vomiting may require intravenous thiamine and vitamin B complex supplementation 1
• Monitor for vitamin deficiencies, especially in severe or prolonged cases 1

Cautions and Pitfalls

• Untreated severe vomiting can lead to Wernicke's encephalopathy, central pontine myelinolysis, and in extreme cases, death 3
• Do not minimize symptoms as "normal morning sickness" as this can lead to undertreatment 4, 5
• Women may avoid seeking treatment due to concerns about medication safety during pregnancy 5
• Always rule out other causes of nausea and vomiting before attributing symptoms to pregnancy 6
• Once NVP progresses, it becomes more difficult to control; early treatment is key to preventing complications 5