--- ---  # Kate Middleton Is Suffering From Hyperemesis Gravidarum. What Is That? by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Sep 4, 2017 2:23 PM UTC  Catherine, Duchess of Cambridge visits the Sunken Garden in the grounds of Kensington Palace on August 30, 2017 in London, England. Catherine, Duchess of Cambridge visits the Sunken Garden in the grounds of Kensington Palace on August 30, 2017 in London, England.Max Mumby/Indigo--Getty Images by [Mahita Gajanan](https://time.com/author/mahita-gajanan/) ## Mahita Gajanan Gajanan is an editor at TIME. Sep 4, 2017 2:23 PM UTC Kate Middleton, also called the Duchess of Cambridge, is [pregnant with her third child](http://time.com/4926420/prince-william-kate-pregnant-third-child/), Kensington Palace said Monday. Middleton and her husband, Prince William, Duke of Cambridge, have not yet revealed a due date for the child. As with her previous two pregnancies, Middleton is suffering from a [severe form of morning sickness](http://time.com/4926420/prince-william-kate-pregnant-third-child/) called hyperemesis gravidarum, which prevented her from attending engagements on Monday. The illness sent Middleton to the hospital during her first pregnancy and recurred during her second pregnancy as well. According to a [TIME report on the condition](http://time.com/3303811/kate-middleton-pregnant-morning-sickness/), having hyperemesis gravidarum once increases its chances of cropping up again: --- > “” --- The condition can be caused by hormonal changes that take place during the first trimester of pregnancy, including the steep rise of human chorionic gonadotropin, which the placenta releases as it prepares to nourish the fetus. What Is Hyperemesis Gravidarum? ```json [{"@context":"https://schema.org","@type":"NewsArticle","@id":"https://time.com/4926496/kate-middleton-hyperemesis-gravidarum/","mainEntityOfPage":{"@type":"WebPage","@id":"https://time.com/4926496/kate-middleton-hyperemesis-gravidarum/"},"headline":"Kate Middleton Is Suffering From Hyperemesis Gravidarum. What Is That?","datePublished":"2017-09-04T14:23:41.000Z","dateModified":"2026-02-23T17:16:13.937Z","description":"As the princess is expecting her third child","url":"https://time.com/4926496/kate-middleton-hyperemesis-gravidarum/","keywords":["medicine","United Kingdom","onetime"],"thumbnailUrl":"https://static.time.com/v3/assets/bltea6093859af6183b/blta6298ca0e6ca89e4/6988dc4ecf40a83933c493b2/kate-middleton-morning-sickness.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","author":[{"@type":"Person","name":"Mahita Gajanan","jobTitle":"Gajanan is an editor at TIME.","url":"https://time.com/author/mahita-gajanan/"}],"articleSection":"Health","image":[{"@type":"ImageObject","url":"https://static.time.com/v3/assets/bltea6093859af6183b/blta6298ca0e6ca89e4/6988dc4ecf40a83933c493b2/kate-middleton-morning-sickness.jpg?branch=production&width=1200&quality=75&auto=webp&crop=1200:675&height=675","width":1200,"height":675,"headline":"The Duke And Duchess Of Cambridge And Prince Harry Visit The White Garden In Kensington Palace","caption":"The Duke And Duchess Of Cambridge And Prince Harry Visit The White Garden In Kensington Palace","creditText":"Max Mumby/Indigo--Getty Images","representativeOfPage":true}],"publisher":{"@type":"Organization","name":"Time","url":"https://time.com/","logo":{"@type":"ImageObject","url":"https://time.com/images/logo.png","width":528,"height":156},"foundingDate":"March 3, 1923","sameAs":["https://www.facebook.com/time","https://www.instagram.com/time/?hl=en","https://twitter.com/time","https://www.pinterest.com/timemagazine"]}},{"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"item":{"@id":"/section/health/","name":"Health"}},{"@type":"ListItem","position":2,"item":{"@id":"/tag/medicine/","name":"medicine"}},{"@type":"ListItem","position":3,"item":{"@id":"https://time.com/4926496/kate-middleton-hyperemesis-gravidarum/","name":"Kate Middleton Is Suffering From Hyperemesis Gravidarum. What Is That?"}}]}] ```