Hyperemesis gravidarum (HG) is a rare condition in which there is severe nausea and vomiting during pregnancy associated with electrolyte deficit, dehydration and weight loss.

What is hyperemesis gravidarum?

Hyperemesis gravidarum is thought to be caused primarily by a rapid increase in the blood levels of certain hormones, such as human chorionic gonadotropin (HCG) and estrogen. The condition is characterized by severe vomiting and nausea, which leads to depletion in vitamin and mineral levels in the body, dehydration, and loss of body weight.

Morning sickness, which is also characterized by nausea and vomiting, is considered a normal phenomenon during pregnancy. Hyperemesis gravidarum is the extreme form of morning sickness. Although the exact etiology of HG is unknown, it is believed that multiple pregnancy, the growth of an abnormally fertilized egg, or overgrowth of placental tissue, are among the causative factors for HG.

What are the signs and symptoms?

The first symptoms of HG start appearing between 4 – 6 weeks of pregnancy, and usually worsen between 9 – 13 weeks of pregnancy. In some cases, the symptoms subside after this period; however, about 20% of pregnant women suffer from HG throughout their pregnancy.

A pregnant woman with HG vomits more than 3 – 4 times a day, which results in dizziness, dehydration, and reduced urination. Because of severe nausea, these women usually suffer from food aversions; as a result, they tend to lose 5% or more of their body weight.

In case of severe dehydration, pregnant women may also suffer headaches, extreme fatigue, confusion, and depression. Some women may also experience cardiovascular symptoms, such as a rapid heart rate, dizziness, and low blood pressure, due to dehydration and electrolyte imbalance.

Other signs and symptoms include weight loss, fainting, low urine output, fruity body odor or breath, or blood-stained vomitus.

When these symptoms and signs are present, medical help must be sought as early as possible.

What is the best way to cope with HG?

For severe HG, hospitalization may be needed. In the hospital, HG patients are mainly treated with intravenous fluids to restore the fluid/electrolyte balance and prevent dehydration. Some patients are also supplemented with vitamins, such as vitamin B6, vitamin C, and thiamine.

Doctors generally do not recommend oral food ingestion while the woman is vomiting. If necessary, nutrients may be supplemented by tube feeding through the nasogastric route (a tube passing through the nose into the stomach). A tube can also be placed surgically through the abdomen into the stomach (percutaneous endoscopic gastrostomy). A special combination of nutrients called total parenteral nutrition is sometimes given intravenously to alleviate the symptoms of HG if a woman cannot eat at all without vomiting.

In most cases, vomiting stops with these remedies. However, if it persists, doctors may prescribe certain medicines, such as antiemetic drugs (to prevent nausea and vomiting), antihistamines (to fight nausea) and anti-reflux drugs (to prevent acid reflux).

Once the vomiting stops, eating frequent small meals composed of bland foods may be helpful to cope with food aversions as well as to reduce the frequency of vomiting. Eating dry foods, such as crackers, or high-protein snacks, also helps reduce the episodes of nausea and vomiting. Patients should begin to take small amounts of fluids and a carbohydrate-rich low-fat diet orally.

To alleviate nausea, doctors generally recommend avoiding specific foods or food odors that aggravate the condition. In addition, doctors sometimes recommend vitamin B6 supplementations to cope with severe nausea.

Another important tip is to drink plenty of fluid when the patient is not nauseating or vomiting. This helps alleviate hydration-related symptoms. Also, taking certain herbs, such as ginger or peppermint, can provide temporary relief.

Bed rest is the best remedy to cope with episodic bouts of severe vomiting.

Acupressure is an important alternative therapy to reduce nausea-related conditions. A pressure-point wrist band is generally used to firmly press and stimulate specific points on the wrist.

If a woman suffers from emotional stress because of HG, such as anxiety or depression, counseling or hypnotherapy may be necessary.

Further Reading

• All Hyperemesis Gravidarum Content
• What is hyperemesis gravidarum (severe morning sickness)?

Written by

Dr. Sanchari Sinha Dutta

Dr. Sanchari Sinha Dutta is a science communicator who believes in spreading the power of science in every corner of the world. She has a Bachelor of Science (B.Sc.) degree and a Master's of Science (M.Sc.) in biology and human physiology. Following her Master's degree, Sanchari went on to study a Ph.D. in human physiology. She has authored more than 10 original research articles, all of which have been published in world renowned international journals.