What is the management of nausea and vomiting in pregnancy?

Management 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 diet and lifestyle modifications, followed by vitamin B6 and doxylamine, and escalating to other antiemetics for moderate to severe cases. 1

Understanding Nausea and Vomiting in Pregnancy (NVP)

Nausea and vomiting affect 30-90% of pregnant women, typically:

• Beginning at 4-6 weeks gestation
• Peaking at 8-12 weeks
• Resolving by 20 weeks in most cases 1

Pathophysiology

• Associated with elevated human chorionic gonadotropin and estrogen
• Influenced by progesterone-induced changes in GI motility and delayed gastric emptying
• Can be exacerbated by specific triggers including certain foods and strong odors 1

Assessment

Severity can be quantified using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score:

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

Treatment Algorithm

Step 1: Diet and Lifestyle Modifications

• Eat small, frequent, bland meals
• Focus on BRAT diet (bananas, rice, applesauce, toast)
• Choose high-protein, low-fat foods
• Avoid spicy, fatty, acidic, and fried foods
• Identify and avoid specific triggers (foods with strong odors, activities) 1

Step 2: Non-Pharmacologic Interventions

• Ginger: 250 mg capsules 4 times daily
• This intervention is recommended by ACOG and has shown efficacy in reducing symptoms 1

Step 3: First-Line Pharmacologic Therapy

• Vitamin B6 (pyridoxine): 10-25 mg every 8 hours
• Doxylamine: 10-20 mg combined with pyridoxine 10-20 mg
• This combination is FDA-approved and recommended by ACOG for persistent NVP 1

Step 4: Second-Line Pharmacologic Therapy (for moderate to severe cases)

• H1-receptor antagonists: promethazine, dimenhydrinate
• Dopamine antagonists: metoclopramide
• Serotonin antagonists: ondansetron
• Intravenous glucocorticoids (for severe, refractory cases) 1

Management of Hyperemesis Gravidarum (HG)

HG affects 0.3-2% of pregnancies and is characterized by:

• Intractable vomiting
• Dehydration
• Weight loss >5% of pre-pregnancy weight
• Electrolyte imbalances 1

Treatment approach for HG:

1. Hospitalization for severe cases
2. IV hydration to correct fluid and electrolyte imbalances
3. Antiemetics at higher doses or combinations
4. Nutritional support including parenteral nutrition if needed
5. Continuous monitoring of maternal and fetal well-being 1

Special Considerations

Timing of Intervention

Early intervention is critical to prevent progression to hyperemesis gravidarum. Don't delay treatment once symptoms are identified. 1

Medication Safety

• Doxylamine and pyridoxine combination has a pregnancy safety rating of A 2
• Most antiemetics used for NVP have not shown evidence of teratogenicity in observational studies 3
• Avoid delaying treatment due to unfounded medication safety concerns 4

Common Pitfalls to Avoid

1. Undertreatment: Symptoms may be minimized by healthcare providers or patients, leading to inadequate management 4
2. Delayed intervention: Once NVP progresses, it becomes more difficult to control symptoms 4
3. Failure to escalate therapy: Not moving to the next treatment step when current management is ineffective
4. Overlooking alternative diagnoses: Ensure nausea and vomiting are pregnancy-related and not due to other causes 5

For optimal outcomes, pregnant women with moderate to severe NVP should be managed by a multidisciplinary team including specialists in obstetrics and gastroenterology, particularly when symptoms are severe or refractory to initial treatment 1.