Alternate Names : Severe Vomiting in Pregnancy
Hyperemesis gravidarum, also called HEG, is severe nausea and
vomiting during pregnancy. It results in dehydration, weight loss, and a
disturbance in the acid-base balance in the body.
Around half of all pregnant women have some nausea and/or
vomiting during the first few months of pregnancy. But HEG occurs in
less than 2 percent of all pregnancies (less than 5 in 1000 women).
What is going on in the body?
In most cases, nausea and vomiting during pregnancy is
mild and does not last long. When it becomes so severe that it interferes
with getting enough fluids and nutrients, the woman may need to
What are the causes and risks of the condition?
There is much that is not known about the causes and risks
related to HEG. Much more study is needed before experts will have
The exact cause of pregnancy-related nausea and vomiting remains
unclear. Some studies suggest the following:
There may be a link between high levels of estrogen or human
chorionic gonadotropin, a hormone that helps the unborn baby to develop.
There is a link between overactive thyroids, a lack of Vitamin B-6, also called
pyridoxine, and psychological factors.
A link between bacteria called Helicobacter pylori and HEG
No one race seems to be at risk for HEG, but it is less common
in the following races:
Asian natives, other than Japan
The risk for HEG seems to decrease as women grow older.
Cigarette smoking also seems to lower the risk. However, smoking presents other
risks to the unborn baby, so should not be used as a preventive factor!
Experts believe the following factors may increase the risk for
being pregnant for the first time
being pregnant with twins, triplets, or more
having HEG with a previous pregnancy
trophoblastic disease of the womb