Hyperemesis Gravidarum – Kate Middleton and Many Others Face This Serious Pregnancy Complication

hyperemesis gravidarum.jpgKensington Palace announced yesterday that Prince Wiliam and his wife, Kate Middleton, the Duke and Duchess of Cambridge, are expecting their third child sometime in 2018.  Kate is approximately 12 weeks pregnant and as in her two previous pregnancies, is suffering from hyperemesis gravidarum.  Science & Sensibility covered this devastating pregnancy illness in depth some years ago, "The Reality and the Research Behind Severe Morning Sickness."

What is hyperemesis gravidarum?

Hyperemesis gravidarum (HG) is a severe form of nausea and vomiting that occurs during pregnancy that affects up to 2% of pregnant people. The nauseousness and vomiting experienced are so severe that the pregnant person is unable to take in enough fluid or nourishment to maintain normal health.  While typical "morning sickness" usually resolves itself during the first trimester, HG is often unrelentingly present throughout the entire pregnancy.  People who suffer from HG may experience:

  • loss of greater than 5% of pre-pregnancy body weight (usually over 10%)
  • dehydration and production of ketones
  • nutritional deficiencies
  • metabolic imbalances
  • difficulty with daily activities
  • dizziness
  • fainting
  • weakness
  • hematemesis (vomiting blood)
  • renal failure

Additionally, there are the complications that come with excessive vomiting that may include gastric ulcers, esophageal bleeding, and malnutrition which unfortunately help continue the cycle of nauseousness.  Babies born to parents who have experienced prolonged HG may experience low birth weight, intrauterine growth restriction (IUGR), preterm delivery and in some cases fetal or neonatal death.

What is the cause of hyperemesis gravidarum?

The etiology of hyperemesis gravidarum is not well understood and there are many theories on its root cause.  Researchers do agree that it is a complex physiological disease likely caused by multiple factors.  The current theories for HG center around known pregnancy-related factors like hormonal changes (e.g. estrogen increase) and physical changes (e.g. relaxed esophageal sphincter) since the onset is related to pregnancy and ends before or at delivery. Current research is very limited and there is minimal funding available for research.

Who is most likely to be affected?

People who weigh more than 170 pounds, are nonsmokers, have twin (or more) pregnancies, trophoblastic disease, and are younger than 20 years old are the most likely to have hyperemesis gravidarum. The likelihood may decrease after age 35. Hyperemesis gravidarum is most common in first pregnancies and if someone had it before they are likely to have it in subsequent pregnancies as well. Some of the risk factors for people most likely to be affected by HG include:

  • Untreated asthma
  • High saturated fat diet
  • Posttraumatic stress disorder (PTSD)
  • Excessive social stress (not a cause, but worsens existing HG)
  • Multiple gestations (twins or more)
  • Food cravings and aversions before and during pregnancy
  • Epilepsy
  • History of:
    • Nausea and vomiting during pregnancy
    • Motion sickness
    • Sensitivity to oral contraceptives
    • Nausea premenstrually
    • Migraine headaches
    • Allergies
    • Gall bladder disease
    • Gastritis or ulcers
    • Mother/sister with HG
    • High blood pressure
    • Liver disease
    • Kidney disease
    • Poor diet

HG has an emotional impact too

There is an emotional and social component to hyperemesis gravidarum as well.  People who are dealing with HG are more likely to suffer from prenatal mood and anxiety disorders, miss significant amounts of work, face challenges with relationships with their partner and other family members, and have their household income adversely affected. 

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Resources for people who are experiencing hyperemesis gravidarum

her-logo-7.pngIt can be very stressful for pregnant people dealing with HG.  Receiving sensitive and appropriate medical care from health care providers who recognize the physical and emotional impact is important.  There is a great website, The HER Foundation (Hyperemesis Education and Research) is a very useful organization for those dealing with HG.  There is a parent section where pregnant people can participate in online forums with their peers, get survival tips, read about current treatment recommendations and connect online with others who are sharing or have shared a similar experience.  They can also use the health care provider directory to find a practitioner who specializes in treating people with HG in their area.

The HER Foundation website has a dedicated section for health care professionals that help them to be up to date on the most current information and treatment methods.  Finally, there is also a "family and friends" section for those who have a loved one with HG.  Here, people can learn how to best support their partner or family member and get answers to their own questions.

New HG App in beta testing mode

Finally, the HER Foundation in cooperation with UCLA Health is releasing an HG health app this month to help collect information for a research study.  If you have any students, clients or patients currently experiencing hyperemesis gravidarum, they may be interested in participating, if they qualify.  More info on accessing the app can be found here


Whether a princess or a commoner, hyperemesis gravidarum can affect any pregnant person and make their pregnancy a very uncomfortable and difficult experience physically and emotionally.  Childbirth educators and other birth professionals can share resources such as the HER Foundation with those suffering.  What additional resources would you share with someone who is dealing with this, as Princess Kate is now?  Let us know in the comments section.

1 Comment


September 6, 2017 04:03 AM by Samantha Phillips, LCCE

Thank you for posting this article. I had been a nurse for a few years before I even took care of a patient with this problem, I know that morning sickness is common but this takes it to an extreme and can be very debilitating to those who get it. Good article for anyone to better understand this illness.

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