Hyperemesis gravidarum is extreme, persistent nausea and vomiting during pregnancy that can lead to dehydration.A.D.A.M.

Causes, incidence, and risk factors

Nearly all women have some nausea or vomiting (morning sickness), particularly during the first 3 months of pregnancy. The cause of nausea and vomiting during pregnancy is believed to be a rapidly rising blood level of a hormone called human chorionic gonadotropin (HCG). HCG is released by the placenta.

Extreme nausea and vomiting during pregnancy can happen if you are pregnant with twins (or more babies) or if you have a hydatidiform mole.

Symptoms

• Severe, persistent nausea during pregnancy, often leads to weight loss
• Lightheadedness or fainting

Signs and tests

The doctor will do a physical exam. Blood pressure may be low. Pulse may be high.

The following laboratory tests will be done to check for signs of dehydration:

• Hematocrit
• Urine ketones

Your doctor may need to run tests to make sure you do not have liver and gastrointestinal problems.

A pregnancy ultrasound will be done to see if you are carrying twins or more babies. Ultrasound also checks for a hydatidiform mole.

Treatment

Small, frequent meals and eating dry foods such as crackers may help relieve uncomplicated nausea.

Drink plenty of fluids. Increase fluids during times of the day when you feel least nauseated. Seltzer, ginger ale, or other sparkling waters may be helpful.

Vitamin B6 (no more than 100 mg daily) has been shown to decrease nausea in early pregnancy. Ask your health care provider if this vitamin might help you.

If your nausea and vomiting is so severe that you and your baby might be in danger, your doctor will prescribe anti-nausea medicine. If your case is very severe, you will likely be admitted to the hospital. There, fluids will be given to you through an IV.

Expectations (prognosis)

Nausea and vomiting is usually worst between 2 and 12 weeks of pregnancy and goes away by the second half of pregnancy. Sometimes it will last longer. With proper identification of symptoms and careful follow-up, serious complications for the baby or mother are rare.

Complications

Too much vomiting is harmful because it leads to dehydration and poor weight gain during pregnancy.

Social or psychological problems may be associated with this disorder of pregnancy. If these problems exist, they need to be identified and taken care of by the health care provider.

Calling your health care provider

Call your health care provider if you are pregnant and have severe nausea and vomiting.

References

1. Cappell MS. Hepatic and gastrointestinal diseases. In: Gabbe SG, Niebyl JR, Simpson JL. Obstetrics: Normal and Problem Pregnancies. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 45.
2. Jewell D, Young G. Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2003;(4):CD000145. [PubMed: 14583914]

Review Date: 11/8/2012.

Reviewed by: Susan Storck, MD, FACOG, Chief, Eastside Department of Obstetrics and Gynecology, Group Health Cooperative of Puget Sound, Bellevue, Washington; Clinical Teaching Faculty, Department of Obstetrics and Gynecology, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.