For decades we believed that extreme nausea during pregnancy was caused by “hormones.” A large study found the real culprit

The beginning of pregnancy for many is associated with horrible nausea and vomiting that have become almost an inevitable and deeply annoying toll in pregnancy and that many women fear. And the reality is that, for a percentage of these women, nausea becomes a big problem and evolves into a very serious form called hyperemesis gravidarum.

What was believed. At first, the most classic reviews They pointed squarely at the ‘hormonal dance’ that pregnant women experience while the placenta is forming. Here the peaks of human chorionic gonadotropin (which is the hormone that pregnancy tests detect), along with estrogens and progesterone, were the main responsible for this discomfort.

However, in clinical practice, the exact cause remained uncertain, since it was not understood why some women only felt mild morning sickness and others ended up hospitalized due to the severe dehydration caused by vomiting. And the answer was in the DNA.

A great study. Here science has dotted the i’s with an article published in Nature which has analyzed the data of almost 11,000 cases of hyperemesis gravidarum and contrasted it with more than 420,000 women who did not have this problem.

The result. He targeted ten genes associated with this severe form of extreme nausea, but among all of them the GDF15 gene emerged as the main culprit. And here the different experts point out that the developing fetus and the placenta produce the hormone GDF15, which is produced from the gene that we mentioned before and sends it directly to the blood, causing this nausea.

Although the key is not just how much hormone is produced, but the degree of prior exposure the mother had to this hormone before pregnancy. In this way, women who had low levels of GDF15 before becoming pregnant turn out to be much more sensitive to the sudden surge of this hormone from the fetus, which triggers the most severe symptoms of nausea and vomiting.

A discovery with evidence. Despite the forcefulness that accompanies this evidence, the study suggests that the gene GDF15 It is the main cause, but not the only one. The fact that there are other genes involved demonstrates that hyperemesis gravidarum is a multifactorial condition so calling it the “sole cause” would be scientifically inaccurate, but classifying it as the most determining genetic factor is, today, a fact supported by the best peer-reviewed literature.

What does it mean? Identifying GDF15 as the main biological switch of this problem is undoubtedly the first step to be able to apply a treatment that can help these future mothers who suffer from significant vomiting during pregnancy, and especially in the first trimester. Although it is true that this does not explain many other symptoms of pregnancy, such as heartburn or that some things begin to feel bad ‘just because’. Although there is still a lot of research ahead to discover them.

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