Early pregnancy is often known for morning sickness. While women who experience it may disagree, doctors like hearing that their patients are undergoing the condition. It turns out that it serves an important purpose in protecting an unborn child.
Scientists have long wondered why two-thirds of healthy pregnancies start off with morning sickness. It had been thought that the quick rush to the washroom to throw up was because of a conflict between mother and embryo. That idea has been dismissed after noticing it is a human condition and not one that is prone to other mammals.
According to a
new study in the July issue of the journal
American Naturalist Samuel Flaxman, an evolutionary biologist at the University of Colorado at Boulder and his colleague Paul Sherman at Cornell University has some new findings about the conditions that make sense.
What is now understood is that morning sickness is triggered by the sight, smell, or taste of meats and strong-tasting vegetables that can harbour microbes or birth defect inducing chemicals and alcohol and cigarette smoke.
The condition of morning sickness peaks between the sixth week and the eighteenth week of pregnancy where the embroy is most susceptible to chemical disruption. Humans tend to have a wide range of diet which other mammals do not and the pregnant woman has evolved to rid herself of dangerous chemicals before they can harm their unborn child.
"To say that morning sickness is uncomfortable is a real understatement, and a lot of people are looking at ways to deal with it. But if nausea and vomiting truly serve a useful function, then one has to look more carefully at strategies for dealing with these symptoms," Flaxman told LiveScience.
While these ideas may be a start at understanding the complexities of morning sickness little is honestly known on the condition.
"We're really interested in a more exhaustive analysis to see if morning sickness really does only occur in human beings, or whether there are other animals out there," Flaxman said.
