(Severe Morning Sickness; Persistent Vomiting of Pregnancy; HG)
by Cynthia M. Johnson, MA
Hyperemesis gravidarum (HG) is severe nausea and vomiting during pregnancy. It is not common.
The cause is not known. There are many thoughts about what may cause it, such as:
HG is more common in young pregnant women. It is also more common in pregnant women who are Asian or Black.
Other things that may raise the risk are:
Problems may be:
The doctor will ask about your symptoms and health history. A physical exam will be done. Blood and urine tests may also be done.
Other tests may be:
The goal of treatment is to manage symptoms to prevent weight loss and dehydration. Choices are:
The risk of this problem may be lowered by taking prenatal vitamins for 1 month before becoming pregnant.
The American Congress of Obstetricians and Gynecologists
The Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada (SOGC)
About hyperemesis gravidarum. HER Foundation website. Available at:
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Accessed November 24, 2020.
American College of Obstetrics and Gynecology. Practice Bulletin 189: nausea and vomiting of pregnancy. Obstet Gynecol 2018 Jan;131(1):e15.
Nausea and vomiting in pregnancy. EBSCO DynaMed website. Available at: https://www.dynamed.com/condition/nausea-and-vomiting-in-pregnancy. Accessed November 24, 2020.
Nausea and vomiting of pregnancy. The American College of Obstetricians and Gynecologists website. Available at: https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/01/nausea-and-vomiting-of-pregnancy. Accessed November 24, 2020.
Last reviewed September 2020 by EBSCO Medical Review Board Marcin Chwistek, MD
Last Updated: 4/20/2021