Princess Kate's morning sickness explained

SPRINGFIELD, Mass. (WWLP) - Princess Kate and Prince William are expecting their first child, but so far, it's been a difficult pregnancy for the Princess.

The Princess, who also has the title Duchess of Cambridge, is being treated at a London hospital for acute morning sickness.

Morning sickness, a combination of nausea and vomiting, is experienced by many pregnant women. The unpleasant condition usually goes away after the first trimester. The Princess’s condition is more severe than most, however, and she is requiring extra hydration and nutrients.

About one out of every 300 pregnant women experiences this type of severe morning sickness during the first trimester. Those who fall into this category usually lose about five percent of their body weight while suffering from it.

“What the Duchess is experiencing is called hyperemesis, which is the extreme version of the nausea in pregnancy,” said Dr. Katherine White of Baystate Medical Center. “Any woman who is hospitalized for this very much needs inpatient care temporarily.”

Interestingly, this condition can last up to 20 weeks, which is about 5 months.

This condition may provide a clue as to the gender of the baby the Princess is carrying, though the statistical trend does not show a huge disparity. 56% of mothers who are hospitalized in early pregnancy had girls, compared with 44% who had boys.