When there are complex fertility problems such as Endometriosis with obstruction of the fallopian tubes or severe decrease in sperm motility requires more sophisticated assisted reproduction techniques. One of them is In Vitro Fertilization.
In Vitro Fertilization consists of extracting eggs from the ovary and taking them to the laboratory. There, under controlled conditions of temperature and humidity, they are put in contact with the spouse’s sperm for fertilization to occur. They are then left in an incubator for 72 hours until the first cell divisions occur. Once it has become an embryo with several cells, it is transferred to the uterus to continue its growth.
With In Vitro Fertilization, some of the natural barriers to fertilization are overcome, such as: the distance that sperm must travel throughout the woman’s reproductive system before they can reach the egg or the probability that the tube will not be able to catch the egg after ovulation. In fact, in vitro fertilization controls many parts of the fertilization process and is very efficient (>90%) in achieving fertilization and obtaining embryos. However, when the embryo is put back into the uterus, this process is no longer controlled and the embryo may or may not implant. This results in the efficiency of In Vitro Fertilization falling and the probability of a pregnancy is 45% in one attempt in women under 35 years of age.
The age of the woman is the most important predictor of success with In Vitro Fertilization. While it is 45% or more in women of 35 years of age, it is only 27% in women of 40 years of age and 9% in women of 42. Why is this? Because of the physiological fact that a woman produces new eggs even before birth. After birth, not only are no new eggs produced, but they also begin to be used up rapidly (about 1,500 per month). The end result is that the older you are, the fewer eggs. Eggs have also been stored for years and begin to deteriorate and their fertilization potential decreases. For this reason, women are recommended when they approach the age of 35 to pay attention to defining their reproductive situation and not to postpone it until after the age of 40.
