When we think of the biology behind conception, we think about the ‘fastest’ sperm reaching the egg and creating a foetus, right?
Well, according to a 2020 study from Stockholm University and Manchester University NHS Foundation Trust not so much. In fact, it is the egg that seems to have more agency in this process, as they use chemical signs to “choose” sperm.
That’s right, while we may spend a lot of time choosing our partner, our reproductive system does the same.
“Human eggs release chemicals called chemoattractants that attract sperm to unfertilised eggs. We wanted to know if eggs use these chemical signals to pick which sperm they attract,” said John Fitzpatrick, an Associate Professor at Stockholm University.
The egg does not always agree with the woman’s choice of partner
Much like the awkward discussions in the group chat when you’re dating somebody who they don’t approve of, your egg can also actually disagree with your choice of partner and work against you.
Very funny, when you think about it.
Professor Fitzpatrick explained that sperm have only one job – to fertilise eggs – so it doesn’t make sense for them to be choosy. Eggs on the other hand can benefit by picking high quality or genetically compatible sperm.
As interesting and mind-blowing as this is, professors believe that it could also be hopeful for future research and treatment around fertility.
Professor Daniel Brison, a senior author on the study said: “Research on the way eggs and sperm interact will advance fertility treatments and may eventually help us understand some of the currently ‘unexplained’ causes of infertility in couples.”
He added: “I’d like to thank every person who took part in this study and contributed to these findings, which may benefit couples struggling with infertility in future.”
How very exciting!