What is hyperemesis gravidarum?

Many pregnant women have some nausea and sometimes vomiting in the first trimester. This is called morning sickness. Symptoms are often more severe in the morning. But nausea and vomiting with pregnancy can happen at any time of the day. Some women may feel sick throughout the pregnancy.

A few pregnant women have a severe kind of nausea and vomiting called hyperemesis gravidarum. With this condition, nausea and vomiting may be all day long. These women often lose weight and get dehydrated. They may also have changes in the body's chemical processes.

What causes hyperemesis gravidarum?

Doctors don't know what causes hyperemesis gravidarum. It may be related to pregnancy hormones. 

Who is at risk for hyperemesis gravidarum?

The condition is more common in women who are pregnant with twins or more. It’s also more common in women with migraines. Women with a family history of the condition or who had the condition in a past pregnancy are more likely to have it with future pregnancies.

What are the symptoms of hyperemesis gravidarum?

The most common symptoms are:

• Constant nausea, especially during the first trimester.

• Vomiting after eating or drinking.

• Vomiting not linked to eating.

• Weight loss. This is especially true if it is 5% or more of what you weighed before pregnancy.

• Signs of fluid loss (dehydration). These include dry mouth, thirst, small amounts of dark urine, and feeling lightheaded.

The symptoms may look like other health conditions. Always see your doctor for a diagnosis.

How is hyperemesis gravidarum diagnosed?

Your doctor will review your health history and do a physical exam. They will also look for other signs, such as weight loss and dehydration. Blood tests can check for too little or too much of the body's minerals (electrolytes).

How is hyperemesis gravidarum treated?

Treatment aims to:

• Ease nausea and vomiting.

• Replace fluids and electrolytes.

• Improve nutrition and weight gain.

You will likely need to stay in the hospital. All food and drink are stopped for a short time (temporarily). This gives the digestive tract a rest. You will often need I.V. (intravenous) fluids to replace fluids you have lost. The I.V. fluids also fix problems with minerals (electrolytes) in your body. You may need a sedative and anti-vomiting medicine. If other treatments don't work, you may need steroids or tube feedings.

What are possible complications of hyperemesis gravidarum?

The condition can lead to:

• Fluid and electrolyte problems.

• Poor nutrition.

• Liver damage and yellowing of the skin, eyes, and mucous membranes (jaundice).

• B vitamin (thiamine) deficiency.  

• Poor growth of the developing baby.

Key points about hyperemesis gravidarum

• This condition is a severe form of nausea and vomiting of pregnancy that affects a small number of women.

• Nausea and vomiting may be constant. You may lose weight, get dehydrated, and have changes in the body's chemicals (electrolytes).

• The cause may be linked to pregnancy hormones. 

• It is more common in women who are pregnant with twins or more, and in women with migraines.

• You may need to stay in the hospital for treatment. You will often need I.V. fluids to replace fluids you have lost.

Next steps

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.

• Before your visit, write down questions you want answered.

• Bring someone with you to help you ask questions and remember what your doctor tells you.

• At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.

• Know why a new medicine or treatment is prescribed, and how it will help you. Also know what the side effects are.

• Ask if your condition can be treated in other ways.

• Know why a test or procedure is recommended and what the results could mean.

• Know what to expect if you do not take the medicine or have the test or procedure.

• If you have a follow-up appointment, write down the date, time, and purpose for that visit.

• Know how you can contact your doctor if you have questions, including after office hours or on weekends.