Morning sickness can last for one day or nine months. Mamas-to-be may experience waves of nausea or hours of vomiting. And, most women are curious to know what causes the sickness. In many studies, researchers test or compare human behavior to animals. Fortunately for other living reproductive animals, humans appear to be the only species that get ill during the expecting months, which has made it tough to decipher the cause.

To see what researchers think may cause morning sickness,


In the July issue of the journal American Naturalist, Samuel Flaxman and his colleague Paul Sherman said morning sickness is triggered in these specific circumstances:

  • The sight, smell, or taste of meats and strong-tasting vegetables, which were historically likely to contain foodborne microbes or birth-defect-inducing chemicals
  • Alcohol and cigarette smoke.

The researchers believe the mother's body is naturally alerting her to stay away from harmful agents, thereby protecting the growing embryo.

While all of this sounds good, I have to wonder about the rest of us that didn't deal with the dreaded sickness. While pregnant with my daughter, I almost craved nausea because it made me feel secure. Having breezed through pregnancy and ended up with a healthy babe, I would never do that again.

Does morning sickness comfort you during pregnancy?