What causes ‘extreme morning sickness’? What we know, don’t know and suspect about hyperemesis gravidarum

Most women experience some nausea and vomiting in early pregnancy.

Although this is called morning sickness, it can happen at any time of day. Up to 80% of women report nausea and vomiting throughout the day.

While morning sickness is unpleasant and can be incapacitating, milder forms are usually manageable and often get better after the first three months of pregnancy.

But around one…

© La Conversation - lundi 12 janvier 2026