The announcement that Kate Middleton, Duchess of Cambridge (and, despite our title, not a princess, like Diana was, for arcane reasons that only experts in Teutonic monarchy understand) is expecting her first child is also bringing attention to a little-known pregnancy condition known as hyperemesis gravidarum (HG), a severe form of nausea and vomiting in pregnancy that can be debilitating because it causes serious dehydration and malnutrition. 

 Hyperemesis gravidarum is generally marked by unrelenting nausea and vomiting that prevents women from eating or drinking and unable to keep anything down for prolonged periods so it's more than morning sickness. Pregnant women who suffer from HG often lose weight during pregnancy and have difficulty carrying on daily activities and those with the most severe symptoms are often hospitalized or placed on intravenous feeding.

 Diagnosis is usually made by measuring weight loss, checking for ketones, and assessing the overall condition of the mother. Early intervention is important. Severe vomiting and nausea alone can cause complications including debilitating fatigue, gastric irritation, ketosis and malnutrition. Aggressive care early in pregnancy is very important to prevent these and more life-threatening complications. 

Kate Middleton. Link: Sky Go

It's estimated up to 2 percent of pregnant women in the U.S. are diagnosed with HG, and the advocacy group HER Foundation believes it is higher due to the visits they receive on their site. HG is not fully understood and a cause is not known but speculations abound and it may be a complex physiological disease caused by multiple factors.

Recent estimations are that HG costs nearly $200 million annually just for inpatient hospitalization. Many women are treated outside the hospital to save costs, so the actual cost may be greater. 

Dr. Marlena Fejzo, who has been conducting HG research at UCLA says, "I hope that Duchess Middleton is getting proper support and care including a thiamine shot if she is unable to tolerate vitamins to prevent a severe but completely avoidable HG-related condition, Wernicke's Encephalopathy. I also hope the suffering of Duchess Middleton leads to more awareness, funding, and participation in research for this devastating and misunderstood pregnancy disease so that scientists like myself, can find answers. My research focuses on identification of genes and risk factors for HG to identify the cause and cure and working with the HER Foundation."