Hyperemesis Gravidarum

What Is Hyperemesis Gravidarum? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Deborah Shapiro
By Medically Reviewed by 
Reviewed:
Medically Reviewed
Nausea and vomiting is a common occurrence in pregnancy, with at least 70 percent of women experiencing some form of it, according to the March of Dimes. It’s typically referred to as morning sickness, though it can happen at any time of day.

But sometimes the symptoms are so extreme — severe, persistent nausea, vomiting, and weight loss during pregnancy — that it may be diagnosed as a less common disorder known as hyperemesis gravidarum.

Hyperemesis gravidarum can lead to dehydration and nutrient loss, affecting both the health of a pregnant woman and the fetus she's carrying. The nausea can be debilitating, interfering with daily activities and quality of life.

It usually subsides at between 14 and 20 weeks of gestation.

Women with hyperemesis gravidarum have an increased risk of preterm labor and preeclampsia, among other complications, but the risk is low.

Signs and Symptoms of Hyperemesis Gravidarum

The primary symptom of hyperemesis gravidarum is severe nausea and vomiting, meaning more than four episodes a day.

This vomiting can lead to:
  • Feeling dizzy, lightheaded, and faint
  • Losing more than 5 percent of body weight
  • Becoming dehydrated, with signs of dehydration such as dark urine and dry skin
  • Electrolyte and nutritional imbalances
  • Increased salivation

  • Rapid heart rate

  • Low blood pressure
  • Headaches
  • Yellowing of the skin and eyes (jaundice)
  • Depression and anxiety

Causes and Risk Factors of Hyperemesis Gravidarum

While there is no proven cause of hyperemesis gravidarum, a number of possibilities have been proposed and studied over the years. The most recent research points to genetics and the role that the placenta and appetite genes GDF15 and IGFBP7 may play.

A study implicating these genes, published in March 2018 in Nature Communications, noted that more research into a causal relationship is necessary.

It has also been proposed that rising levels of the hormone human chorionic gonadotropin (HCG) in pregnancy contribute to hyperemesis gravidarum.

And higher levels of estrogen and progesterone have been suspected to play a role in nausea symptoms and digestive issues.

Other associations include:

  • Increase in blood levels of thyroxine (a growth-regulating hormone produced by the thyroid), which has been documented in up to 73 percent of hyperemesis gravidarum cases, according to the HER Foundation

  • Abnormal tissue growth in the uterus, called a molar pregnancy

The following factors may increase your chances of getting hyperemesis gravidarum:

  • Having the condition during a previous pregnancy
  • Other women in your family developed the condition

  • Multiple pregnancy

  • First-time pregnancy
  • Obesity
  • Younger maternal age; risk may decrease after age 35

How Is Hyperemesis Gravidarum Diagnosed?

Your doctor will perform a physical exam and order the following lab tests to assess signs of dehydration.

  • A complete blood count
  • A serum electrolyte test (blood test)
  • Ketones urine test (when the body isn't getting enough nutrients, it begins to break down fat, which leads to an increase in waste products known as ketones)

An ultrasound can confirm if you are carrying twins or multiples and can diagnose a molar pregnancy.

Prognosis of Hyperemesis Gravidarum

According to the Merck Manual, it's uncommon for hyperemesis gravidarum to last beyond 16 to 18 weeks. But if it does persist, it may cause serious liver damage and other complications (see Complications, below).

Duration of Hyperemesis Gravidarum

Hyperemesis gravidarum usually continues beyond the first trimester and stops by 20 weeks of gestation.

It's estimated that up to 20 percent of women with HG will experience symptoms for most or all of their pregnancy.

Treatment and Medication Options for Hyperemesis Gravidarum

If you have severe symptoms of hyperemesis gravidarum, you may need to be hospitalized. According to the National Organization for Rare Disorders, hyperemesis gravidarum is the second leading cause of hospitalization in early pregnancy.

For less severe cases, you may be able to seek treatment at home or at a doctor's office.

While the course of treatment for hyperemesis gravidarum varies from person to person, your doctor may recommend one or more of the following:

  • Vitamin B6

  • Small, frequent meals that include dry, bland foods such as crackers
  • Intravenous fluids to help with dehydration
  • For severe cases, parenteral nutrition, in which an intravenous (IV) solution of vitamins and nutrients is given as a substitute for food

Medication Options

First-line medications shown to be effective in treating vomiting and nausea and safe for pregnancy are pyridoxine and doxylamine. If a particular patient doesn't respond well to this treatment, a combination of other medications may be tried, including antihistamines such as Antivert (meclizine), diphenhydramine, and dopamine antagonists such as Inapsine (droperidol), or Reglan (metoclopramide).

RELATED: 8 Surprising Health Benefits of B Vitamins

Alternative and Complementary Therapies

Evidence concerning the effectiveness of the following therapies for hyperemesis gravidarum remains inconclusive. But when used in addition to traditional medical interventions, they may help alleviate symptoms. They include:

  • Acupuncture and acupressure
  • Hypnosis
  • Light therapy (to help with depression)
Ginger, whether taken in tea or through a capsule, is also thought to be helpful.

Before trying any of the above, make sure to discuss their use with your healthcare provider.

Prevention of Hyperemesis Gravidarum

While there's no way to completely prevent hyperemesis gravidarum, Harvard Health Publishing notes that women who take a multivitamin before getting pregnant, such as a prenatal vitamin, are less prone to severe symptoms.

If morning sickness develops during pregnancy, you may reduce the severity and duration of symptoms by eating small, frequent meals of bland foods rather than spicy ones, waiting to take any iron supplements until the nausea has passed, and, on your doctor's recommendation, trying acupressure, vitamin B6, or ginger.

Complications of Hyperemesis Gravidarum

The main risks to women with hyperemesis gravidarum are dehydration, electrolyte imbalances, and weight loss.

Women with prolonged hyperemesis gravidarum are at greater risk for preterm labor and preeclampsia, according to the HER Foundation. But as mentioned above, this risk is low.

In addition, there’s a potential for babies to be born at a low weight.

Rare but severe complications of hyperemesis gravidarum can be life-threatening and include:

A disorder known as Wernicke encephalopathy is caused by a vitamin B1 deficiency, which can be caused by hyperemesis gravidarum. Symptoms include vision changes, loss of muscle coordination, confusion, and loss of mental activity resulting in coma.

Research and Statistics: Who Gets Hyperemesis Gravidarum?

More than 192,000 hospital visits or admissions for hyperemesis occur annually in the United States.

The condition is estimated to occur in .5 to 2 percent of pregnant women.

Related Conditions of Hyperemesis Gravidarum

A number of gastrointestinal conditions can cause symptoms similar to hyperemesis gravidarum and may need to be ruled out during diagnosis. These include:

And the following conditions can also have similar symptoms:

  • Inflammation of the kidneys and pelvis (pyelonephritis)
  • Degeneration of abnormal growths of fibrous tissue (fibroid degeneration)
  • Twisting of the ovary (ovarian torsion)

Resources We Love

Essential Organizations

HER (Hyperemesis Education and Research) Foundation

This nonprofit organization is devoted to supporting and educating women who are experiencing hyperemesis gravidarum or have gone through it in the past. HER offers comprehensive info on what the condition is, how to manage it physically and emotionally, and the latest research. Different sections for pregnant women as well as their friends and family target and address a range of needs.

National Organization for Rare Diseases (NORD)

NORD works with individual patients and organizations to bring awareness to rare disorders. In addition to a highly informative, up-to-date page on hyperemesis gravidarum, this nonprofit also has a resource center for patients and caregivers.

Favorite Podcast

The BMJ Podcast

The BMJ (British Medical Journal) podcasts focus on a variety of health issues. The episode on hyperemesis gravidarum, "The Bone-Crushing Nausea of Hyperemesis," features of panel of experts — women who have had hyperemesis gravidarum themselves and also research or treat it — discussing what the condition is like and how to manage it.

Helpful App

HG Care

UCLA Health partnered with the HER Foundation on this free iOS app for women experiencing hyperemesis gravidarum. It tracks how little (or how much) you've eaten and whether your treatments are working, sends alerts if your weight drops or you're getting dehydrated and need medical attention, reminds you to take meds, and more.

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