IVF. A long history of infertility
IVF (in vitro fertilization) is the in vitro fertilization of an egg (i.e. fertilization in a special medical container or in a test tube, after which the embryo is grown in a special nutrient medium). In a few days, the embryo is transferred to the woman’s uterus where pregnancy will later develop. First, IVF is a method of treating infertility. In this case, the main indication for in vitro fertilization is tubal infertility. Such a diagnosis is given to women when they have full or partial obstruction of the fallopian tubes. The worst thing is that their patency cannot be restored (for example, in the presence of adhesions after inflammatory diseases of the abdominal cavity, after operations such as appendicitis, if it was complicated by a purulent process in the abdominal cavity), or the absence of fallopian tubes after an ectopic pregnancy. In addition, IVF is also used in immunological infertility in the body of a woman, when the antibodies that destroy her husband’s sperm are formed. IVF is also effective in male infertility when the produced sperm is not enough.
The history of IVF began long before the birth of the first child from the test tube and as it usually happens in science, the first in this field were laboratory animals.
At the beginning of the twentieth century, researchers of the reproductive function began discussing under what conditions the fertilization of a human egg in a test tube is possible, but the colossal complexity of the fertilization process did not allow it to go far. Despite the success in studying the reproduction of animals, it was only in the 1960s when the science of man had the courage to approach the shocking task of conceiving a child in vitro. The task consisted of a chain of subtasks, which the researchers had to solve for the first time. Doctors and researchers had to learn from nature the following:
- Control the maturation of oocytes to obtain oocytes at the optimal stage of development for IVF.
- Preserve and increase sperm activity in vitro.
- Recreate the conditions in vitro facilitating fertilization and then developing the embryo.
- Implant a viable embryo in the mother’s uterus.
The oocyte is an immature ovule at the stage of maturation. Maturation of oocytes is a process that lasts for life and which is controlled by hormones. Its first stage proceeds in the intrauterine period. At the time of the birth of the girl, 300-400 thousand oocytes are ready in her body but by the age of puberty, their number is reduced to about 16 thousand.
Dr. Edwards and its achievements in IVF
Dr. Edwards began work on infertility at the National Institute for Medical Research in London. He has accumulated a tremendous amount of knowledge about the process of IVF. He was perfectly prepared to move on. His first task was to obtain ready-to-fertilize oocytes. To do this, he needed to determine how immature human oocytes in vitro would continue to develop. From revolutionary experiments with rabbits of the embryologist Pincus, it was known that oocytes of mammals reach maturity in 12 hours. However, Edwards took several years to determine exactly how long oocyte ripens in similar conditions. In 1965, his efforts were rewarded. It turned out that the human oocyte reaches maturity within 37 hours after extraction. The possibility of ripening of oocyte in vitro opened the way to obtaining cells at the optimal stage for IVF. It was only necessary to determine the conditions necessary for laboratory fertilization of the ovum. Edwards managed to fertilize the ovum but the embryo stubbornly refused to develop further. After dividing the embryonic cell into two, the process stopped. Scientific views made us assume that the cause of failure is a too long time that the oocyte spends outside the body. Edwards began to use oocytes, ripened in a natural environment. Edwards has already proved that the maturation of oocytes can be controlled by introducing an analog of luteinizing hormone (which is produced in the pituitary gland and controls the maturation of oocyte in the natural course of events). Solving this simple problem allowed him to calculate with high accuracy in time all the stages of maturation and determine the time when the human cell matured and was ready to leave the follicle.
There was only a technical problem. The researchers did not have a technique that would allow the optimal amount of oocytes to be extracted from the ovary at the desired stage of development. Dr. Patrick Steptoe, a gynecologist, came to the aid of Dr. Edwards. Steptoe is considered the father of British laparoscopy (a method that allows doctors to see the organs of the abdominal cavity and receive samples for analysis using a device inserted into the incision near the navel). Dr. Edwards realized that laparoscopy allows getting the oocytes at the right time and the right quality.
The next two years can be considered a historical break in the work on IVF. By 1971, the discovery of Dr. Edwards allowed the embryos to grow to the age of the blastocyst (a cell structure capable of gaining a foothold on the uterine wall). Steptoe and Edwards started the IVF experiments using this technique. The 1970s were the most dramatic in the history of IVF. All pregnancies were spontaneously interrupted at an early stage. It took more than a hundred failures to understand that the matter is in the imperfection of the protocol of hormonal stimulation. Hormones, which the patient received as stimulators of oocyte maturation, interfered with the fixation of embryos on the uterine wall. The protocol of hormonal therapy was changed, and in 1976, Edwards and Steptoe recorded the first successful pregnancy. However, pregnancy was ectopic and it had to be interrupted. Edwards and Steptoe refused hormonal stimulation of the ovaries. Now they relied on the natural ovulation cycle of the patient. The first child born by the method of IVF was in 1978. The achievement of Edwards and Stephen became stunning in the history of IVF.
Today, IVF becomes a routine. For the cultivation of oocytes, physiological liquids that are closer to natural ones are selected. Methods of sperm delivery at the destination are being improved. More and more sophisticated hormonal schemes are being developed. Clinics are fighting for the percentage of successful pregnancies. In 1990, more than twenty thousand children in the world appeared with the help of IVF. In 2010, there are about four million. This is the main achievement of IVF.