(Severe Morning Sickness; Persistent Vomiting of Pregnancy; HG)
Hyperemesis gravidarum (HG) is an uncommon condition characterized by frequent, persistent, and severe vomiting and nausea during pregnancy. As a result, you may be unable to take in a sufficient amount of food and fluids. It can cause a weight loss of more than 5% of your pre-pregnancy body weight. This can also cause dehydration and vitamin and mineral deficiencies. Treatment may require hospitalization.
HG is a more severe form of nausea and vomiting of pregnancy (NVP, morning sickness). Morning sickness affects anywhere between 70% to 80% of pregnant women. HG is estimated to occur in up to 2% of pregnancies.
There are many theories about the causes of HG, but none have been confirmed. HG is a complex disease that is likely caused by many factors. Some of these include:
- Vitamin B deficiency
- Human chorionic gonadotropin (hCG)—hyperemesis is most severe during the period of highest hCG levels
—may be a result of high hCG levels
- High levels of estrogen
- A multiple pregnancy
- Brain nausea-control-center sensitivity to pregnancy changes
|The Brain May Be Cause of Nausea
|Copyright © Nucleus Medical Media, Inc.
Factors that may increase your chance of HG include:
- History of HG in previous pregnancies
- Molar pregnancy—an abnormal mass made up of placental tissue which may or may not contain some fetal tissue
- Mother or sister with HG
- A multiple pregnancy
- Young maternal age
- No previous completed pregnancies
- First-time pregnancy
HG may cause:
- Severe and persistent vomiting, beginning 4 to 6 weeks after conception, peaking at 9-13 weeks, and usually improving and ending by 14-20 weeks
- Weight loss of greater than 5% of original, pre-pregnancy body weight
- Decrease in urine output
- Rapid heartbeat
- Lightheadedness and fainting
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include the following:
- Blood tests
- Urine tests
- Weight measurement—to determine if you have lost weight
- Overall condition—ability to perform daily activities, psychological state of mind
Treating HG symptoms early in pregnancy can make you less sick in the long run and can decrease recovery time. Because HG is caused by many factors that vary among women, it is difficult to find a treatment that works for everyone. Talk with your doctor about the best treatment plan for you. Treatment options include the following:
Try to eat frequent, small meals, bland or dry foods, high-protein choices.
Reducing nausea, and thus allowing eating and drinking, will hasten recovery. Due to the risk of stating that a drug is safe for use during pregnancy, very few pharmaceutical manufacturers will say that their drugs are intended for a pregnancy condition like HG. However, doctors often recommend that women with HG take certain anti-nausea medications, balancing the potential benefits and risks. Talk to your doctor about the right medications for you.
A common and safe remedy is to take supplemental vitamin B6 (pyridoxine). The American Congress of Obstetricians and Gynecologists recommends that first-line treatment of nausea and vomiting of pregnancy should start with pyridoxine with or without doxylamine. Pyridoxine has been found to be effective in significantly reducing severe vomiting.
IV Hydration and Anti-nausea Medications
In urgent doctor visit situations, HG can be managed by IV fluids and vitamins. This can sometimes be done without hospitalization. Very rarely, some people require IV fluids throughout the entire pregnancy.
If you are unable to tolerate food by mouth, you may need to receive nutrition through an IV. This is called parenteral nutrition. A special kind of catheter is placed in a large vein and liquid nutrition is given. This can sometimes be done without hospitalization.
may help to reduce nausea. Acupressure is when pressure is applied to
Termination of Pregnancy
In extreme cases, induced abortion may be considered.
Many of the conditions that lead to HG are not preventable. To help reduce your chance of nausea during pregnancy:
- Avoid smells, foods, or other things that stimulate nausea
- Eat frequent, small meals
- Do not allow yourself to get too hungry or too full
The American Congress of Obstetricians and Gynecologists
The Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada (SOGC)
About hyperemesis. HER Foundation website. Available at:
http://www.helpher.org/hyperemesis-gravidarum. Updated April 18, 2013. Accessed June 6, 2016.
Acupuncture. EBSCO Natural and Alternative Treatments website. Available at: http://www.ebscohost.com/biomedical-libraries/natural-alternative-treatments. Updated February 26, 2016. Accessed June 6, 2016.
Herrell HE. Nausea and vomiting of pregnancy.
Am Fam Physician.
Morning sickness: nausea and vomiting of pregnancy. The American College of Obstetricians and Gynecologists website. Available at:
http://www.acog.org/~/media/For%20Patients/faq126.pdf?dmc=1&ts=20130806T1444487894. Updated December 2015. Accessed June 6, 2016.
Nausea and vomiting in pregnancy. EBSCO DynaMed Plus website. Available at:
http://www.dynamed.com/topics/dmp~AN~T114643/Nausea-and-vomiting-in-pregnancy. Updated August 26, 2016. Accessed June 6, 2016.
Practice Bulletin No. 153: nausea and vomiting of pregnancy. Obstet Gynecol. 2015;126(3):e12-e24.