The royal pregnancy: Is Kate Middleton’s health at risk?

As Kate Middleton remains in the hospital for treatment of severe morning sickness, many Brits and Americans – delighted with the news of a royal pregnancy – are wishing the Duchess of Cambridge a speedy recovery and an overall healthy pregnancy.

But does Kate’s medical condition pose a threat to her health as her baby (or babies) comes to term?

Most likely not.  Kate is currently suffering from hyperemesis gravidarum (HG), a severe form of nausea and vomiting often associated with pregnancy.  While very uncommon – affecting up to 2 percent of pregnancies – the condition does not pose any significant health threats to the mother or the baby.

“Nausea, vomiting in pregnancy occurs in up to 90 percent of women who are pregnant, and has a huge spectrum,” Dr. Nancy Cossler, a medical director in the department of obstetrics and gynecology for UH Case Medical Center in Cleveland, Ohio, told FoxNews.com.  “At the more severe end of the spectrum, there is more significant nausea and vomiting, but nobody has really defined this with certainty. A general definition that’s used is that there is weight loss of more than 5 percent of your pre-pregnancy body weight and evidence of dehydration, so that’s how we differentiate....However, hyperemesis has not be shown to have poor outcome with babies and mothers."

With Kate having such a slim figure, there is some concern regarding her losing more weight during this early time.

“For very underweight women, they may have more difficulty with pregnancy.  She has less weight to lose, so it’s probably more difficult for her in that way,” Cossler, who has not treated Kate, said.

In order to ensure that Kate remains healthy and does not lose any more weight, doctors will replace her fluids through the use of an IV, Cossler said.  Common treatment for hyperemesis includes monitoring food intake and making sure to follow a less inflammatory diet.

“We restart their diet slowly, and we tell them to avoid triggers that might provoke an episode of vomiting,” Cossler said of treatment.  “We tell them to eat six small meals a day, and eat just what appeals to you.  And most women who have severe enough nausea and vomiting rebound and regain the weight they lost.”

While some women with hyperemesis may continue to have less severe nausea and vomiting up until their third trimester, most often women with this condition will notice symptoms go away by 16 weeks.

As for what may have caused Kate’s hyperemesis, Cossler said doctors have not come up with a definitive culprit.  Any stress or unusual circumstances relating to her royal status has probably not affected her pregnancy in any way.

“I think [the stress of being a princess] is unrelated to the pregnancy,” Cossler said.  “There are lots of working women who have stressful jobs.  They’re not the Duchess of Cambridge, but they’re pregnant when they do them.  I think that yes, women have stressful lives, but I think that’s separate from their health during pregnancy.  Pregnancy may ultimately add to stress, however.”