What is the diagnosis and treatment for Hyperemesis Gravidarum (HG), a condition characterized by severe nausea and vomiting during pregnancy?

From the Guidelines

Hyperemesis gravidarum should be managed with a step-up approach, starting with oral antiemetics like doxylamine-pyridoxine, and progressing to intravenous hydration and antiemetics such as ondansetron or metoclopramide if necessary, as recommended by the American College of Obstetricians and Gynecologists (ACOG) and supported by recent studies 1. The goals of management are to prevent dehydration, correct electrolyte abnormalities, and support adequate maternal and fetal nutrition.

• Treatment begins with oral antiemetics like doxylamine-pyridoxine (Diclegis/Diclectin) 10mg/10mg at bedtime, increasing to 2 tablets at bedtime, 1 in the morning, and 1 in the afternoon if needed.
• If oral medications fail, intravenous hydration and antiemetics such as ondansetron 4-8mg IV/PO every 8 hours, metoclopramide 10mg IV/PO every 6-8 hours, or promethazine 12.5-25mg IV/PO every 4-6 hours may be necessary, as suggested by the European Association for the Study of the Liver Clinical Practice Guidelines 1.
• Severe cases may require hospitalization for IV fluids, electrolyte replacement, and possibly total parenteral nutrition.
• Thiamine supplementation (100mg daily) is important to prevent Wernicke's encephalopathy, as recommended by the American Association for the Study of Liver Diseases 1.
• Lifestyle modifications include eating small, frequent meals, avoiding triggers, consuming ginger, and wearing acupressure wristbands. Hyperemesis gravidarum typically improves by 20 weeks gestation but can persist throughout pregnancy.
• The condition likely results from elevated pregnancy hormones (hCG, estrogen) and may have genetic components.
• Regular monitoring of weight, hydration status, and electrolytes is essential for proper management, as emphasized by recent studies 1.

From the Research

Definition and Prevalence of Hyperemesis Gravidarum

• Hyperemesis gravidarum is a severe form of nausea and vomiting in pregnancy, affecting 0.3-1.0% of pregnancies 2
• It is a significant source of morbidity and one of the most common indications for hospitalization in pregnancy 2

Treatment Options for Hyperemesis Gravidarum

• Various interventions have been studied, including acupuncture, metoclopramide, ondansetron, promethazine, corticosteroids, and vitamin B6 2, 3, 4, 5
• A systematic review and meta-analysis found that ondansetron and metoclopramide had similar antiemetic and antinauseant effects, but ondansetron had a better adverse effect profile 3, 5
• Another review found that ginger, vitamin B6, antihistamines, metoclopramide, pyridoxine-doxylamine, and ondansetron were associated with improved symptoms compared to placebo 4

Comparison of Ondansetron and Metoclopramide

• A randomized controlled trial found that ondansetron and metoclopramide had similar efficacy in reducing nausea and vomiting, but ondansetron had fewer side effects such as drowsiness and xerostomia 3
• A systematic review and meta-analysis found no significant difference in efficacy between ondansetron and metoclopramide, but ondansetron was favored due to its trending therapeutic efficacy and better safety profile 5

Other Treatment Options

• Corticosteroids may be associated with benefit in severe cases of hyperemesis gravidarum 4
• Midwife-led outpatient care was associated with fewer hours of hospital admission than routine inpatient admission, with no difference in pregnancy-unique quantification of emesis and nausea score 2