Hyperemesis Gravidarum


  • Nausea and vomiting in pregnancy is a common condition that affects approximately 70–80% of pregnancies.
  • A more severe form of nausea and vomiting, hyperemesis gravidarum, affects 0.5–2% of pregnancies, and can have significant adverse physical and psychological sequela.
  • Hyperemesis gravidarum remains a diagnosis of clinical judgement and is one of the most common indications for hospitalization during pregnancy.
  • Hyperemesis gravidarum 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, hyperemesis gravidarum is a rare condition.
  • Hyperemesis gravidarum is 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
    • Believed to have biomedical and behavioral aspects
    • 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 (GI), reproductive


  • Generally affects young women, primiparous, non-smokers, and non-Caucasians
  • Other risk factors include prior history of hyperemesis, preexisting diabetes, hyperthyroid disorder, psychiatric illness, asthma, and GI disorders.

Hyperemesis gravidarum occurs in 0.5–2% of pregnancies.

Hyperemesis gravidarum is the most common cause of hospitalization in the first half of pregnancy and the second most common cause of hospitalization of all pregnant women.

Etiology and Pathophysiology

Etiology unknown. Proposed influences include:

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

Increased risk if maternal family history of hyperemesis gravidarum

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

Anticipatory guidance regarding dietary habits to avoid dehydration and nutritional depletion

  • Small, frequent meals
  • Avoiding an overly empty or full stomach

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