By assisted fertilization in humans we understand the use of manipulation methods on one or both gametes in order to achieve a pregnancy, regardless of the cause of infertility and the degree of manipulation.
We believe this could be a useful classification.
Artificial insemination with husband’s sperm is one of the most common techniques. The technique consists of depositing some sperm, which has been prepared in the laboratory by using techniques aimed at improving quality, preferably in the uterine cavity.
The most common indications are:
IVF consists of facilitating the fusion of sperm and egg in a dish in the laboratory, outside the human body. If fertilization occurs within the first 48 hours, the embryos are transferred to the uterine cavity through the cervix between 2 and 6 days after fertilization.
When the tubes of the patient are normal, transfer through them has been advocated, either of gametes (sperm and oocytes), which we call GIFT, zygotes (ZIFT) or embryos (TET). These alternatives are not commonly used nowadays, since they are not more effective than transcervical transfer, but should be considered in cases of difficulty in the cervical canal and even for religious reasons (the Catholic Church authorizes GIFT).
IVF is indicated for:
Several procedures have been developed along the last 6-7 years which are aimed at solving the problem of severe male infertility by means of micromanipulation and microinjection of a single sperm cell into the cytoplasm of the oocyte (ICSI), which has emerged as a technique to solve these cases.
ICSI can be carried out with ejaculated sperm or that obtained by microepididymal sperm aspiration (MESA) or testicular sperm aspiration (TESA) from a biopsy. They will be discussed in detail in the corresponding section.
Cryotechnology is a necessary part of IVF programs in order to avoid the risk of multiple pregnancies resulting from the transfer of large numbers of embryos as well as to avoid having to dispose of surplus embryos from large cohorts of oocytes. Today it is a routine procedure that increases the IVF process cumulative pregnancy rate.
It is indicated for:
As a result of certain social and employment reasons, women delay the time of conception and after the age of 40 we find a decrease in fertility due to various factors: reduced embryo implantation capacity, a higher rate of abortions and an increased occurrence of genetic abnormalities.
This means that in many cases only egg donation can be offered as an assisted reproduction technique.