From the Guidelines
The approach to evaluating nausea and vomiting in pregnancy should begin with a thorough history and physical examination, utilizing the Motherisk Pregnancy-Unique Quantification of Emesis score to quantify symptom severity, as recommended by the most recent evidence 1.
Initial Assessment
The initial assessment should include vital signs, weight, hydration status, and laboratory tests including complete blood count, electrolytes, liver function tests, and urinalysis to check for ketones. Ultrasound is recommended to confirm pregnancy viability and rule out multiple gestation or molar pregnancy, which can worsen symptoms.
Quantifying Symptom Severity
The Motherisk Pregnancy-Unique Quantification of Emesis score is a useful tool for quantifying symptom severity, with a maximum score of 15, and severity classified as mild (≤6), moderate (7-12), or severe (13) 1.
Treatment Approach
Treatment typically follows a stepwise approach, starting with dietary modifications like eating small, frequent meals, avoiding triggers, and consuming ginger (250mg four times daily). First-line medications include vitamin B6 (pyridoxine) 10-25mg three times daily, which can be combined with doxylamine 12.5mg three to four times daily, as recommended by the American College of Obstetricians and Gynecologists (ACOG) 1.
Second-Line Options
If symptoms persist, second-line options include antihistamines like dimenhydrinate or promethazine, or dopamine antagonists such as metoclopramide 5-10mg three times daily. For severe cases, ondansetron 4-8mg every 8 hours may be used, though with caution in the first trimester, as suggested by recent guidelines 1.
Severe Cases
Intravenous hydration and hospitalization are necessary for women with severe dehydration, electrolyte abnormalities, or weight loss exceeding 5% of pre-pregnancy weight. This approach balances symptom relief with maternal and fetal safety considerations, and early treatment of nausea and vomiting of pregnancy may reduce progression to hyperemesis gravidarum, as emphasized by recent expert reviews 1.
From the Research
Evaluation Approach
The approach to evaluating nausea and vomiting in pregnancy involves several steps, including:
- Careful evaluation of patients with nonresolving or worsening symptoms to rule out pregnancy-related and nonpregnancy-related causes of severe vomiting 2, 3
- Distinguishing nausea and vomiting of pregnancy from nausea and vomiting related to other causes 4, 5
- Assessing the severity of symptoms, as the woman's perception of her symptoms plays a critical role in the decision of whether, when, and how to treat nausea and vomiting of pregnancy 4, 5
Diagnostic Considerations
Diagnostic considerations include:
- Ruling out pathologic causes of severe vomiting 2
- Identifying hyperemesis gravidarum, a severe form of nausea and vomiting of pregnancy that may have negative implications for maternal and fetal health 2, 6, 3
- Considering the possibility of Helicobacter pylori as a cause of nausea and vomiting of pregnancy 2
Management and Treatment
Management and treatment options include:
- Conservative measures, such as dietary changes, emotional support, and alternative therapy like ginger or acupressure 2, 3
- Pharmacologic therapy, including pyridoxine and doxylamine, which have been shown to be safe and effective treatments 2, 6
- Hospitalization, rehydration therapy, and parenteral nutrition for women with hyperemesis gravidarum or severe vomiting 2, 3