Definition of
Fertilization
It is called fertilization to the process and consequence of fertilizing. This verbin a biological sense, refers to the union of a male reproductive cell with a female reproductive cell to create a new being.
These sex cells are called gametes. When the male gamete fuses with the female gamete by reproduction sexualfertilization occurs, a process that involves the creation of another individual, whose genome derives from the genes of its parents.
It can be said, therefore, that fertilization supposes the creation of a new individual from the genetic mix his parents (one male specimen and one female specimen).
Fertilization begins when the spermatozoon (male gamete) comes into contact with the Ovum (female gamete) and recognition occurs between them. Then the spermatozoon enters the egg and an interaction begins to develop that makes possible the fusion of the respective genetic materials. This is how the zygotewhich is the cell that results from the union of gametes.
Once fertilization has been completed, the zygote develops and goes through various stages: first it reaches the state of embryothen it becomes fetus and finally, when it has achieved the necessary development, it is born as a new individual. In the case of the human being, nine months pass from fertilization to birth.
Natural fertilization in our species occurs when a man and a woman maintain a intercourse and the man ejaculates inside the woman’s vagina, allowing his sperm to come into contact with the eggs. It is also possible to achieve reproduction through the artificial fertilization with the help of technical laboratory.
In 1979 the birth of the first girl to have been conceived by means of the application of a technique of artificial fertilization called in vitromerit that is attributed to doctors Steptoe and Edwards. Before this historic moment in science, there were many years of tests that did not give the expected results.
The process required the extraction of a ovary, which was artificially fertilized. Since only one egg can be obtained in the natural cycle, the doctors took a long time between one test and another. In addition, the ovum must present the appropriate maturity and genetic health for the fertilization of an embryo with a healthy structure, so that it can divide and then be implanted in the uterus.
One of the milestones in IVF came when doctors began using drugs to stimulate ovulation so that more mature eggs could be obtained each cycle. Thanks to this technical advance, it is possible to extract a greater number of embryos, closely study the evolution of each one and finally choose the best ones to implant them in the uterus.
IVF also improved when scientists started using drugs named gonadotropinswhich serve so that premature ovulation does not take place, that is, before the eggs are extracted from the ovaries.
Thanks to having many embryos, in vitro fertilization allowed patients to receive a high number per implantation (in certain countries, up to seven at a time) and this increased the chances of pregnancy. But this did not always bring positive consequences, since one of the most common complications of this technique appeared: multiple pregnancy.
If the man in the couple has problems producing sperm normally, then it is possible to carry out fertilization through a technique known as ICSIwhich consists of injecting the sperm into the cytoplasm of the oocyte.