What is the best approach to manage nausea and vomiting in pregnancy?

From the Guidelines

The best approach to manage nausea and vomiting in pregnancy involves a stepwise strategy starting with lifestyle modifications before considering medications, with vitamin B6 and doxylamine as first-line medication therapy, as recommended by the American College of Obstetricians and Gynecologists (ACOG) 1.

Key Considerations

• Nausea and vomiting of pregnancy (NVP) usually begins at 4–6 weeks, peaks at 8–12 weeks, and subsides by week 20 1.
• The severity of vomiting during pregnancy can be quantified with a scoring system, such as the Motherisk Pregnancy Unique Quantification of Emesis score (Table 1) 1.
• Diet and lifestyle modification are the initial steps in managing these symptoms in pregnancy, including reducing spicy, fatty, acidic, and fried foods, eating small, frequent, and bland meals, and avoiding specific triggers 1.

Treatment Options

• Vitamin B6 (pyridoxine) 10-25mg three times daily is recommended as first-line medication therapy and can be combined with doxylamine 12.5mg (half a tablet of Unisom) at night if needed 1.
• For moderate symptoms, prescription options include promethazine 12.5-25mg every 4-6 hours or metoclopramide 5-10mg three times daily 1.
• For severe cases (hyperemesis gravidarum), ondansetron 4-8mg every 8 hours may be used, though preferably after the first trimester, with a small absolute increase in orofacial and ventricular septal defects 1.

Monitoring and Safety

• Treatment should be individualized based on symptom severity, with close monitoring for effectiveness and side effects 1.
• Most medications are considered safe in pregnancy when used appropriately, though the benefits must outweigh potential risks, with glucocorticosteroids causing an increase in oral clefts incidence when used before 10 weeks of gestation 1.

From the FDA Drug Label

The FDA drug label does not answer the question.

From the Research

Management of Nausea and Vomiting in Pregnancy

• Nausea and vomiting in pregnancy (NVP) affects up to 85% of all women during pregnancy, with the most severe form, hyperemesis gravidarum (HG), affecting 0.3-1.0% of pregnant women 2, 3.
• The best approach to manage NVP involves a combination of lifestyle and dietary changes, as well as pharmacologic treatments 4, 5.
• For mild symptoms, ginger, pyridoxine, antihistamines, and metoclopramide are associated with greater benefit than placebo 3.
• For moderate symptoms, pyridoxine-doxylamine, promethazine, and metoclopramide are associated with greater benefit than placebo, while ondansetron is associated with improvement for a range of symptom severity 3.
• Corticosteroids may be associated with benefit in severe cases of HG 3.
• Initial pharmacologic treatment for HG includes a combination of doxylamine and pyridoxine, with additional interventions including ondansetron or dopamine antagonists such as metoclopramide or promethazine 6.
• Mirtazapine has been suggested as a useful drug for women who are not adequately treated with these medications, with its efficacy described in case studies 6.

Treatment Options

• Lifestyle and dietary changes, such as eating small, frequent meals and avoiding triggers, can help manage mild symptoms of NVP 4, 5.
• Pharmacologic treatments, such as ginger, pyridoxine, antihistamines, and metoclopramide, can be used to manage moderate symptoms 3.
• For severe symptoms of HG, hospitalization may be necessary to correct dehydration and provide supportive care 2.
• Enteral feeding may be effective for very severe symptoms, but is considered an extreme method of treatment 2.
• Day case management for moderate/severe symptoms is feasible, acceptable, and as effective as inpatient care 2.

Economic Considerations

• The economic analysis of treatments for NVP is limited by a lack of effectiveness data, but comparison of costs between treatments highlights the implications of different choices 2.
• The main limitations of the economic analysis are the quantity and quality of the data available, with evidence of some improvement in symptoms for some treatments, but these data may not be transferable across disease severities 2.