What is the appropriate workup and treatment for a 19-year-old female at 10 weeks gestation presenting to the emergency department with vomiting?

Management of Hyperemesis Gravidarum in a 19-Year-Old Pregnant Patient

The 19-year-old female at 10 weeks gestation presenting with vomiting should receive prompt rehydration, electrolyte correction, thiamine supplementation, and antiemetic therapy with doxylamine/pyridoxine as first-line treatment, or ondansetron as second-line therapy if symptoms persist. 1

Initial Assessment

• Evaluate severity using the Motherisk Pregnancy-Unique Quantification of Emesis (PUQE) score, which assesses duration of nausea, frequency of vomiting, and frequency of retching over the past 12 hours 1
• Check for signs of dehydration (orthostatic hypotension, decreased skin turgor) 1
• Assess for weight loss ≥5% of pre-pregnancy weight, which would indicate hyperemesis gravidarum rather than routine nausea and vomiting of pregnancy 1
• Note that nausea and vomiting typically begins at 4-6 weeks, peaks at 8-12 weeks (where this patient is now), and usually subsides by week 20 1

Laboratory Workup

• Complete blood count 1
• Serum electrolytes and glucose 1
• Liver function tests (AST, ALT) - abnormal in approximately 50% of hyperemesis gravidarum cases but typically improve with hydration 1
• Urinalysis for ketonuria 1

Treatment Algorithm

Step 1: Non-pharmacologic Management

• Dietary modifications: small, frequent, bland meals (BRAT diet - bananas, rice, applesauce, toast) 1
• Identify and avoid specific triggers (foods with strong odors) 1
• High-protein, low-fat meals may help reduce symptoms 1

Step 2: First-Line Pharmacologic Treatment

• Vitamin B6 (pyridoxine) 10-25 mg every 8 hours 1
• Doxylamine 10-20 mg combined with pyridoxine 10-20 mg (FDA-approved and ACOG-recommended for persistent nausea and vomiting of pregnancy) 1
• Thiamine (vitamin B1) supplementation at 100 mg daily for minimum 7 days, then 50 mg daily until adequate oral intake is established to prevent Wernicke encephalopathy 1

Step 3: Second-Line Pharmacologic Treatment (if symptoms persist)

• Metoclopramide for moderate symptoms (has similar efficacy to promethazine but fewer side effects) 1
• Ondansetron 8 mg IV/PO every 4-6 hours for severe symptoms 1, 2
• Promethazine 12.5-25 mg PO/PR every 4-6 hours 3, 4

Step 4: Severe Cases Requiring Additional Intervention

• IV hydration with normal saline (0.9% NaCl) with potassium chloride supplementation 4
• Correction of electrolyte abnormalities 1
• For refractory cases, methylprednisolone 16 mg IV every 8 hours for up to 3 days, followed by tapering over 2 weeks (caution in first trimester due to potential risk of cleft palate) 1

Important Considerations

• Early intervention is crucial to prevent progression to hyperemesis gravidarum 1
• Liver enzyme abnormalities typically resolve with hydration; persistent abnormalities should prompt investigation for other etiologies 1
• Ondansetron should be used as second-line therapy after 10 weeks of pregnancy if first-line treatments fail 1
• Monitor for signs of extrapyramidal effects with metoclopramide and promethazine 1
• Consider multidisciplinary approach involving obstetricians, nutritionists, and psychologists for severe cases 1

Discharge Criteria and Follow-up

• Resolution of vomiting and ability to tolerate oral intake 1
• Correction of electrolyte abnormalities 1
• Patient education on continued dietary modifications and medication use 1
• Follow-up appointment to monitor symptoms and adjust treatment as needed 1
• Consider outpatient antiemetic therapy if symptoms are controlled but not resolved 1

Remember that hyperemesis gravidarum can lead to significant maternal morbidity if untreated, including dehydration, weight loss, and electrolyte imbalances, making prompt and appropriate management essential 1.