Until now, what we knew about the time of conception is that, With ejaculation, the sperm would shoot out in a frantic race to the egg, so that only the strongest and fastest would be able to avoid the unsuspected dangers of the cervix to win the fight for fertilization. But a new study indicates that this is not the case.
Fertility experts found that the female body rejects the sperm it does not want on the way to the egg so that the success of conception does not depend only on seminal fluid.
Finnish researchers note that chemicals in the female reproductive system can facilitate or prevent the victorious arrival of sperm to the egg as soon as they enter the cervix. From there, the cervical mucus either favors or sabotages sperm, depending on whether they are genetically suitable or not.
That is women’s reproductive secretions help sperm more likely to give offspring a better genetic makeup and a better immune capacity to fight infections; instead, they obstruct the path of sperm that are not compatible with this logic of preservation of the species.
The authors of the study, published in the Biological Sciences section of the Proceedings of the Royal Society B, analyzed the behavior of the cervical mucus of nine women when combined with the sperm of eight men. They then compared the success of the sperm motility with the genetic characteristics of each person.
His conclusion is that sperm genetically more different from the egg are more likely to travel through the cervical mucus and thus achieve fertilization since this genetic variety can conceive offspring with more diverse genes and, therefore, capable of fighting pathogens and diseases that are also more diverse.
The researchers point out that their investigations can help better understand infertility in some couples, as well as facilitate more personalized and accurate diagnoses.