The hospital admission has served as pregnancy announcement of William and Kate, who married in 2011. The duchess, who, according to palace sources, is in very early stages of pregnancy, is experiencing normal - though in his case, severe - morning sickness.

Between 70 to 80% of pregnant women suffer from. Nausea, despite morning called, can be triggered at any time of day. I usually start around the sixth week of pregnancy, calculated from the last menstrual period and usually disappears by the end of the first quarter.

The usual recommendations for controlling these morning sickness include avoiding large meals, drinking and eating small amounts throughout the day, avoid cooking smelly or other activities that may cause nausea. The smell of lemon or ginger can relieve nausea, like taking watermelon or chips.

Hospitalization of Princess Kate suggests your morning is unusually severe disorder, a condition known as hyperemesis gravidarum ("hyper" is excessive "emesis" means vomiting, and "gravid" means pregnancy) and can prevent women retain the stomach any food or water and may require intravenous fluids and nutrients.

The difference between the typical morning sickness and hyperemesis gravidarum can be very marked. A woman in a state of normal pregnancy can often feel nauseous, but just going to throw up sometimes. A woman with hyperemesis gravidarum experience severe vomiting, and symptoms do not go away as easily as the pregnancy progresses, but there are medications to control it.

A 2008 study found that morning sickness can protect embryos to encourage mothers to avoid unpleasant substances such as cigarette smoke, alcohol, and strongly flavored foods. Morning sickness have peaked in the first trimester of pregnancy, when the organs of the developing embryo are most susceptible to possible chemical alteration.

Picture: By Pat Pilon from Ottawa, Canada (Shannon, July 1, 2011Uploaded by Skeezix1000) [CC-BY-2.0], via Wikimedia Commons