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 deficiencyHuman chorionic gonadotropin (hCG)—hyperemesis is most severe during the period of highest hCG levelsHyperthyroidism
—may be a result of high hCG levels
High levels of estrogenA multiple pregnancyBrain nausea-control-center sensitivity to pregnancy changes
The Brain May Be Cause of Nausea
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Factors that may increase your chance of HG include: History of HG in previous pregnanciesMolar pregnancy—an abnormal mass made up of placental tissue which may or may not contain some fetal tissueMother or sister with HGA multiple pregnancyYoung maternal ageNo previous completed pregnanciesFirst-time pregnancyObesity
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 weeksWeight loss of greater than 5% of original, pre-pregnancy body weightDecrease in urine outputDehydrationRapid heartbeatHeadachesConfusionLightheadedness and fainting
Your doctor will ask about your symptoms and medical history. A physical exam will be done. Tests may include the following: Blood testsUrine testsWeight measurement—to determine if you have lost weightOverall 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.
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
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 nauseaEat frequent, small mealsDo not allow yourself to get too hungry or too full
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.
Practice Bulletin No. 153: nausea and vomiting of pregnancy. Obstet Gynecol. 2015;126(3):e12-e24.
Last reviewed June 2016 by James Cornell, MD
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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