Cause of Nausea During Pregnancy? It’s Still Unsettled
Waves of nausea are part and parcel of pregnancy for many women, especially in the first few months of carrying that little bundle. As you sit there trying to choke down that dry cracker without hurling, you most likely are not brimming with intellectual curiosity about the science behind all this.
But when a better moment comes, the curious can treat themselves to some scholarly theorizing on the subject in the June issue of the Quarterly Review of Biology, which relishes such topics. The quarterly has published articles before on morning sickness and on such subjects as why women have periods.
In a 36-page extravaganza, Cornell University biologists Samuel M. Flaxman and Paul W. Sherman write about their study of tens of thousands of pregnancies, whether or not they resulted in birth. Their main conclusion: Women feel barfy in the first trimester of pregnancy to protect the mother and fetus from damage caused by food-borne infections, toxins produced by bacteria and chemicals in certain plants. Such chemicals might interfere with the development of the embryo in those crucial first weeks, when arms and legs and toes and brains are all busy being formed.
The mother’s immune system, the authors point out, is less feisty during pregnancy so she won’t reject her own fetus as a foreign body. That also means she’s less able to fight off food-borne infections.
Thus it makes sense, they say--from an evolutionary point of view--that expectant mothers react with nausea in the first trimester against suspect foods. That they often develop a distaste for meats, a prime source of germs. And that they tend to eschew strong-tasting vegetables, which may be rich in chemicals that, while harmless for an older person, could interfere with fetal development.
But other researchers have different theories about morning sickness. Some believe that hormonal changes are responsible for the nausea.
Whatever the case, this doesn’t mean that women who don’t feel queasy during the first trimester have anything to fear: Most babies, by far, are born perfectly healthy, regardless of whether the mother experienced morning sickness.
Nevertheless, Sherman suggests that morning sickness--known in medical circles as NVP, for “nausea and vomiting in pregnancy”--should have its name changed to “wellness insurance.” (Will this catch on? We’re not sure.)
More Fascinating Factoids
Inspired by its recent write-up on joint-cracking, we visited https://www.medicinenet.com and assembled a few more health factoids for you to fascinate (or bother) your friends with.
* If you placed all the blood vessels of your body in a straight line (which we don’t advise), they would stretch 60,000 miles.
* The average fingernail grows 1 centimeter in 100 days. Nails grow faster in young people, in males and in the summer. Fingernails of the right hand grow faster in right-handed folks, while those of the left grow faster in lefties.
* The heart beats 2.5 billion times in the average lifetime.
* The average person has 2 million sweat glands. (We know some people whom we suspect have many more.)
* A normal person’s nose will produce about two quarts of mucus a day, which helps cleanse and moisten the respiratory tract. (Surely not!)
Have you stumbled upon a health-related tidbit that has Booster Shots written all over it? Send your ideas and suggestions by regular mail to Rosie Mestel, Los Angeles Times, Times Mirror Square, Los Angeles, CA 90053, or by e-mail to: rosie.mestel@latimes.com.
