What is HG?

Around 1% of pregnant women experience severe nausea and vomiting known as hyperemesis gravidarum (HG). The exact figure varies depending on the study you read but is quoted between 0.3% and 3%.

A woman with HG generally has no respite from severe nausea, vomits many times each day and finds that eating or drinking makes her feel worse, leading to weight loss rather than gain. If this continues without treatment, she becomes dehydrated and malnourished. Some women also suffer from ptyalism, which means that they cannot swallow their own saliva without vomiting.

What causes it?

There is no research confirming the cause at present. Theories include high levels of the pregnancy hormone Human Chorionic Gonadotrophin (hCG), some make links to thyroid levels, some blame Helicobacter Pylori which causes stomach ulcers, and occasionally HG is confused with hydatidiform mole (molar pregnancy). There is certainly an element of genetics to it too - if there is HG in your family, you're more likely to suffer it yourself. There is some new anecdotal evidence to suggest that liver function may also play a part. It is likely that a variety of factors cause HG, which might account for the difficulty in finding effective treatment in some cases.

It is important that a woman who appears to have HG is tested to rule out thyroid problems, H. Pylori and molar pregnancy. Thyroid and H. Pylori cases can be treated and there is quick relief from nausea and vomiting. Molar pregnancies also need urgent attention.

Treatment

NHS treatment varies widely in the UK at the moment but usually includes one or more of the following:

• GP-prescribed drugs to reduce the vomiting
• Hospitalisation for intravenous (IV) fluids
• Hospitalisation for injected/IV drugs to reduce vomiting
• Hospitalisation for artificial feeding (rare)

For more information on conventional treatment, see Treatments, Drug information and Self-help tips. You can also use alternative medicine - see the Alternative medicine section under Treatments.

Duration

Unlike morning sickness, which usually starts at week 8-9 and reduces around week 12-14, HG frequently begins by week 6 and continues until around week 20, but may continue throughout pregnancy in some cases. Some women report that the nausea disappears as soon as they give birth, while for others it takes several days. In rare (usually very severe) cases it may take longer. See also the Frequently asked questions on this site.

Outcome

The developing baby is rarely affected by the mother's illness, although in severe and prolonged cases the baby is more likely to have a low birth weight. See also the Frequently asked questions on this site.

More information

You might find the answer to all your questions in our Frequently asked questions section. However, if you still find there are some issues bothering you, you can often find more detailed answers on another site - visit the Hyperemesis Research and Education Organization. However, this is based in the United States so you should come back to our site or contact us for specific information about how to get help in the UK.