Hyperemesis Gravidarum


  • Nausea and vomiting in pregnancy is a common condition that affects approximately 70–80% of pregnancies.
  • Hyperemesis gravidarum (HG) is a severe form of nausea and vomiting in pregnancy that affects 0.5–2% of pregnancies and can have significant adverse physical and psychological sequela.
  • HG is a diagnosis of clinical judgement and is one of the most common indications for hospitalization during pregnancy.
  • HG is associated with several adverse fetal outcomes including preterm delivery, low birth weight, small for gestation age, low 5-minute Apgar scores, and neurodevelopmental delay.


  • Although morning sickness is common during pregnancy, HG is a rare condition.
  • Intractable vomiting in a pregnant woman that interferes with fluid and electrolyte balance as well as nutrition:
    • Usually associated with the first 8 to 20 weeks of pregnancy
    • Associated with high estrogen and human chorionic gonadotropin (hCG) levels
    • Symptoms usually begin ~2 weeks after first missed period, peak around the 12th week, and resolve by the 20th week
  • System(s) affected: endocrine/metabolic, gastrointestinal, reproductive


  • Generally affects young women, primiparous, non-smokers, and nonwhite people
  • Other risk factors: prior history of hyperemesis, pre-existing diabetes, hyperthyroid disorder, psychiatric illness, asthma, and GI disorders

HG occurs in 0.5–2% of pregnancies.

The most common cause of hospitalization in the first half of pregnancy; the second most common cause of hospitalization of all pregnant women

Etiology and Pathophysiology

Etiology is unknown; proposed influences include the following:

  • Hyperthyroidism
  • Hyperparathyroidism
  • Pregnancy hormones
  • Liver dysfunction
  • Autonomic nervous system dysfunction
  • CNS neoplasm
  • Addison disease
  • Possible psychological factors

Increased risk if maternal family history of HG

Risk Factors

Nulliparity; multiple gestations; history of migraines; history of motion sickness; black or Asian women; gestational trophoblastic disease; fetus with trisomy 21; female fetus; possible association with Helicobacter pylori infection

General Prevention

Guidance regarding dietary habits to avoid dehydration and nutritional depletion

  • Small, frequent meals
  • Avoid an overly empty or full stomach.
  • Avoid greasy, spicy, and fatty foods.
  • Eat bland, low-fiber, high-protein snacks.

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