We Finally Know What Causes Morning Sickness – And That's One Step Closer To A Cure

Here's why some experience vomiting, and some don't.
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Have you ever wondered why you suffered from morning sickness, yet your friend didn’t? For example, I was one of the lucky ones who didn’t suffer from nausea and vomiting during my pregnancy, yet most of my friends did.

Now, thanks to new research, scientists have found what actually causes some people to suffer from nausea and vomiting during their pregnancy.

Until recently the cause was unknown, but a Cambridge-led study has discovered it’s due to a hormone produced by the foetus — a protein known as GDF15.

In fact, depending on how much exposure to the hormone the parent had before getting pregnant determines how sick the mother feels.

Professor Sir Stephen O’Rahilly, Co-Director of the Institute of Metabolic Science and Director of the Medical Research Council Metabolic Diseases Unit at the University of Cambridge, who led the collaboration, said: “Most women who become pregnant will experience nausea and sickness at some point, and while this is not pleasant, for some women it can be much worse — they’ll become so sick they require treatment and even hospitalisation. We now know why.

“Knowing this gives us a clue as to how we might prevent this from happening. It also makes us more confident that preventing GDF15 from accessing its highly specific receptor in the mother’s brain will ultimately form the basis for an effective and safe way of treating this disorder.”

The study highlighted than now that the cause is known, a potential way to prevent pregnancy sickness could be by exposing mothers to the hormone before their pregnancy in order to build up resilience.

Earlier in 2018, geneticist Marlena Fejzo who holds a doctorate in genetics, and her colleagues published a paper showing that two genes, GDF15 and IGFBP7, are involved in hyperemesis gravidarum — a severe type of nausea and vomiting.

Finally, here was scientific evidence that the condition is not psychological.

But pregnancy is not the only time a person has the hormone in their body. For instance, cancer patients dealing with cachexia, a syndrome that causes weight loss, loss of appetite and more, is caused by rising levels of the GDF15 hormone.

“Unhealthy tissues make it, so, whenever you’re sick, like if you have a viral or bacterial infection,”said Marlena.

“It goes up when you have kidney damage or liver damage. Any time any organ in your body or any cells in your body are under some kind of physical stress, they are going to produce this hormone,” she added,

The theory is that humans evolved this gene to prevent them from feeling hunger and going out to hunt for food when their bodies were in a weakened state, as they were more likely to be taken down by a predator while ill.