Why Does Morning Sickness Happen and When Does it Start?

I’ll always remember a young woman who came into my office complaining of a sudden onset of bloating and feeling sick to her stomach. I asked her, “Is there any chance that you’re pregnant?” to which she responded, “No, I don’t think so”.

Later that day, I shared the great news with her and her husband that they were expecting.

This scenario is not uncommon. Many women experience some symptoms of pregnancy before they realize that they missed their period.

In this post, I’d like to share some highlights of when morning sickness starts and why it happens in the first place.

First things First

  1. +Morning sickness is incredibly common, affecting nearly 50-90% of women.
  2. +Severe morning sickness is uncommon. Only about 1-2% of women will have symptoms requiring hosptilization.
  3. +Younger women are more likely to get morning sickness than older women who are pregnant.


The More the Better?

  1. +Women with twins and multiple gestations have a higher risk of morning sickness.
  2. +Supertasters are much more likely to get morning sickness.
  3. +Women with acid reflux are more likely to suffer from morning sickness
  4. +Women with motion sickness are more likely to get morning sickness.

Girl Power

  1. +Women pregnant with baby girls are more likely to have a severe form of morning sickness called hyperemesis gravidarum.

But Why Me?

  1. +One of the leading thoughts on why women get morning sickness is hormones. The same hormone that tells you you’re pregnant, hCG, is a common culprit.
  2. +The other female hormone, progesterone, is also implicated. It has a tendency to slow down your intestines and lead to all sorts of not-so-fun things like acid reflux, bloating, and constipation-all of which can make morning sickness worse.
  3. Interestingly, recent studies suggest that women who have the stomach infection Helicobacter pylori are at much higher risk of morning sickness.
    HCG may be a leading cause of morning sickness

When Did It All Start?

  1. +Morning sickness can start as early as five weeks into your pregnancy. It often lasts for up to 18 weeks.
  2. +The worst time for most women with morning sickness is around nine weeks of gestation.
  3. +About 1 in 20 women will have morning sickness all the way to delivery.

It’s Not Morning and I’m Sick!

  1. +Morning sickness is a misnomer. Most women with morning sickness have symptoms throughout the day.

Is it All Bad?

  1. +Of course not, your little bundle of joy is on their way!
  2. +Also, take comfort in knowing that women with morning sickness are less likely to have a miscarriage.


I hope this list of morning sickness highlights proves helpful. For more on treatments of morning sickness, be sure to check out http://tummydrops.com/blog/when-does-morning-sickness-start/.


Congratulations on your new baby!


Dustin James MD

The Tummy Doc

Board-Certified Gastroenterologist

Author of The Complete Idiot’s Guide® to Digestive Health




Reading, sharing, or other utilization of this article does not establish a doctor patient relationship with the article’s author. As always, be sure to consult with your physician regarding your health related issues before initiating or changing any medicines.