Hyperemesis Gravidarum Workup

Updated: Jan 04, 2017
  • Author: Dotun A Ogunyemi, MD; Chief Editor: Christine Isaacs, MD  more...
  • Print
Workup

Laboratory Studies

Initial laboratory studies for hyperemesis gravidarum should include the following:

  • Urinalysis for ketones and specific gravity: A sign of starvation, ketones may be harmful to fetal development. High specific gravity occurs with volume depletion.
  • Serum electrolytes and ketones: Assess electrolyte status to evaluate for low potassium or sodium, identify hyperchloremic metabolic alkalosis or acidosis, and evaluate renal function and volume status.
  • Liver enzymes and bilirubin: Elevated transaminase levels may occur in as many as 50% of patients with hyperemesis gravidarum. Mild transaminitis often resolves once the nausea has resolved. Significantly elevated liver enzymes, however, may be a sign of another underlying liver condition, such as hepatitis (viral, ischemic, autoimmune), or some other etiology of liver injury. [2]
  • Amylase/lipase: Amylase level is elevated in approximately 10% of patients with hyperemesis gravidarum. Lipase, when combined with amylase, can increase the specificity in diagnosing pancreatitis as an etiology.
  • TSH, free thyroxine: Hyperemesis gravidarum is often associated with a transient hyperthyroidism and suppressed TSH levels in 50-60% of cases. However, an elevated free thyroxine may suggest that overt hyperthyroidism is present, thus necessitating further workup and treatment. [3]
  • Urine culture: This may be indicated because urinary tract infection is common in pregnancy and can be associated with nausea and vomiting.
  • Calcium level: Consider measuring Ca ++ levels. Some rare cases have been reported of hypercalcemia being associated with hyperemesis gravidarum, resulting from hyperparathyroidism.
  • Hematocrit: This may be elevated because of volume contraction.
  • Hepatitis panel: If clinically indicated, hepatitis A, B, or C may be confused with hyperemesis gravidarum. [1]
Next:

Imaging Studies

Ultrasonography

Obstetric ultrasonography is usually warranted in patients with hyperemesis gravidarum to evaluate for multiple gestations or trophoblastic disease.

Additional imaging studies generally are not needed unless the clinical presentation is atypical (eg, nausea and/or vomiting beginning after 9-10 wk of gestation, nausea and/or vomiting persisting after 20-22 wk, acute severe exacerbation) or another disorder is suggested based on history or physical examination findings.

If indicated clinically, performing upper abdominal ultrasonography to evaluate the pancreas and/or biliary tree appears to be a low-risk study.

Other imaging modalities

In patients with abdominal pain or upper gastrointestinal bleeding, upper gastrointestinal endoscopy appears to be safe in pregnancy, although careful monitoring is suggested.

In rare cases, abdominal computed tomography (CT) scanning or even magnetic resonance imaging (MRI) may be indicated if appendicitis is under consideration as a cause of nausea and vomiting in pregnancy.

Previous