MANILA, Philippines – The Royal Palace’s announcement of Prince William and Duchess Kate’s pregnancy had to be made prematurely because of the Duchess of Cambridge’s hospitalization due to severe morning sickness.

Morning sickness occurs in 70 to 80 percent of pregnant women, according to the American Pregnancy Association. It usually begins in the 6^th week of pregnancy.

This should make it a natural condition for Kate who, according to a Royal Palace spokesperson, is around 12 weeks pregnant. 

But severe morning sickness is another matter. A condition known as hyperemesis gravidarum, it only occurs in 1 in 200 women and is potentially fatal.

Here are some quick facts about the disease and how those affected, royal couple included, can mitigate it.

These facts are based on the findings of the Hyperemesis Education & Research Foundation and the American Pregnancy Association:

1) HG is a pregnancy-related disease that causes severe nausea and vomiting. A woman with regular morning sickness constantly feels nauseated but vomits occasionally; a woman with HG vomits constantly, sometimes up to 30 or 40 times a day.

2) Symptoms of HG include weight loss of more than 2 pounds (0.9 kilograms) or 5 percent of your body weight upon conception, inability to keep water down enough to stay hydrated and the vomiting of bile or blood.

3) The severe vomiting prompts hospitalization so that the patient can keep down fluids and nutrients from food through the use of an intravenous line (IV).

4) While nausea subsides 12 weeks into the pregnancy for morning sickness, nausea continues throughout the pregnancy of HG-diagnosed women.

5) HG can stop after 21 weeks but may last for the whole pregnancy.

6) The exact cause of HG is still unknown. However, several factors are said to contribute: hormonal changes, dehydration, lack of nutrients in the body, overall stress on the body, changes in internal chemistry due to pregnancy.

Research suggests that HG may even be genetic among some women.

7) There is no official medication for HG and so it is best to consult a doctor.

8) Women who experience HG in one pregnancy are likely to experience it in future pregnancies.

9) Treating HG at its onset is crucial. Delaying treatment will make it harder to control the vomiting cycle whereas treating it early will decrease recovery time.

10) Preterm labor is more common among HG-diagnosed mothers. This leads to early delivery and babies that are smaller than expected.

– Rappler.com