Clinical embryology is a branch of science that studies the development of the fetus, from the moment of conception to the birth of a child. Knowledge in this area is required for all doctors.
The tasks of embryology are to timely identify genetic abnormalities and disorders during childbearing, to identify diseases in children immediately after birth. To date, doctors are applying existing knowledge in this area to determine the causes of infertility and eliminate them, as well as to develop contraceptive drugs. In order to solve the problem of infertility, IVF, transplantation of the embryo into the uterus, as well as the cultivation of eggs, have become very popular.
History of development of embryology
Like many other sciences, clinical embryology originated in antiquity. Aristotle's scientific writings contain detailed descriptions of the chicken embryo. Around the same time, such points of view on developmental processes as epigenesis and preformism arose.
Dutch Jan Swammerdam studied the development and metamorphosis of insects. His compatriot Anthony van Leeuwenhoek discovered parthenogenesis in aphids and studied human spermatozoa. The Italian Marcello Malpighi investigated the development of the chicken embryo, studied the anatomic althe structure of tissues and organs of various plants and animals. From the point of view of scientists, nothing new is formed in the development process, all parts of the embryo are already formed and are in the egg, but they cannot be seen due to their small size. In the future, only the growth of the embryo occurs. The spontaneous generation of organisms seemed unlikely to preformist scientists. They believed that the embryo is either in the egg or in the sperm. At the same time, they could not understand how the genetic characteristics of the second parent are transmitted to the offspring.
In the first half of the 19th century, firm facts appeared that contradicted preformism. At this time, comparative anatomy and systematics made great strides. One of the main methods in the field of microbiology is the comparative method. In connection with these developments, comparative embryology was formed. The best results in this area were obtained by Karl Baer, who is considered the founder of embryology.
Having thoroughly studied the embryonic development of absolutely all classes of vertebrates, the scientist found that at an early stage all embryos are similar to each other, and differences acquire only in the course of subsequent development. This made it possible to form the law of germline similarity.
The development of this direction occurred after the research of Charles Darwin. Soviet scientists I. I. Mechnikov and A. O. Kovalevsky made a particularly great contribution to clinical embryology.
Feature of Embryology
Clinical embryology is a science that studies the development of an embryo in the mother's body or egg shells. Processfetal development, from the moment of conception to the birth of a child, can be divided into several separate stages:
- zygote formation;
- blastula formation as a result of cell division;
- organ formation;
- histogenesis and organogenesis of tissues and organs of the fetus, as well as the placenta;
- formation of body systems.
In addition, thanks to embryology, difficult, critical periods of development have become known that can adversely affect the condition of the fetus under the influence of certain factors.
Study of Embryology
Modern embryology studies the process of embryo formation. Scientists say that the development of the embryo occurs in three main stages:
- from conception to 2 weeks of development;
- from the 3rd week, when the embryo becomes a fetus;
- from the development of important organs to the birth of a child.
During the IVF procedure, embryology is important, because thanks to modern possibilities, optimal conditions are created for the onset and normal course of pregnancy. When applying scientific data, specialists will help to determine in advance and prevent the possibility of fetal malformations. Thanks to the science of embryology, scientists have identified dangerous periods in the development of a child:
- fertilization;
- implantation of the embryo into the walls of the uterus;
- formation of basic tissues;
- head educationbrain;
- development of organs and systems;
- birth process.
During these periods, the influence of various negative factors can provoke a slowdown, abnormal development or even death of the fetus. Clinical embryology deals with the problem of abnormality and also seeks to eliminate them in order to avoid violations.
How embryologists work
Doctors-embryologists deal with the problems of fertilization, and also exercise control over the development of the embryo, up to the stage of transferring it to the uterine cavity. During IVF, embryology determines the presence of problems, and also looks for ways to solve them. The embryologist carries out a set of measures for the diagnosis and subsequent treatment of couples who have come to the hospital with a problem of infertility.
With a competent approach to each couple, the doctor conducts:
- insemination - the introduction of spermatozoa into the uterine cavity;
- assessment of sperm quality and fertilization results;
- cultivation and transfer of embryos into the uterine cavity.
Doctor-embryologist creates the most favorable conditions for the birth of a new life, helping to bypass the barriers that prevent fertilization in natural conditions. A positive result is achieved through the use of modern technologies.
What happens in embryology labs
At the Embryology Center, the doctor examines couples to determine the causes of infertility, and then prescribes treatment. ATlaboratory, the most crucial stage of IVF is taking place, since all conditions are created that mimic the environment of the human body, fertilization and embryo cultivation are carried out.
In the Embryology Center, a reproductive doctor initially works with the patient, who, with the help of hormonal drugs, provokes the growth of eggs in the woman's ovaries, monitors their growth and prepares the uterus for embryo transfer. Using a special needle, eggs are removed from the body, which are then sent to the laboratory. In the laboratory, the eggs are cleaned from the outer shell to facilitate the passage of the sperm, and placed in a special bowl with a nutrient medium.
After egg retrieval, the man donates sperm, which also undergoes special processing. As a result, the most mobile spermatozoa are selected. Then the active sperm cells are transferred to the bowl with the egg, from this moment the fertilization procedure begins. A day later, the nutrient medium for the zygote is replaced with a fresh one. The doctor observes the embryos for 4-5 days, and then implants them into the woman's body.
What is the embryological protocol
Information about the fertilization, obtained during the IVF process, is recorded in a special document called the embryological protocol. It contains all the information related to the cultivation and growth of embryos.
18 hours after the procedure, the doctor givespreliminary information regarding the number of fertilized eggs. The documentation indicates data regarding the thickness of the shell that forms around the embryo, fragmentation and ordering of the cells.
Stages of embryonic development
The process of fertilization is very complex and involves the fusion of female and male germ cells, during which the restoration of the set of chromosomes is observed and a new fertilized egg is formed. Fertilization occurs in the fallopian tubes, by the fusion of sperm and eggs.
A zygote is formed in a woman's body after fertilization within 12 hours. After a few days, the zygote divides, then two blastomeres are formed, one of which is larger and darker. From the larger part, the embryo, placenta, and other tissues are formed. The embryo is implanted in the lining of the uterus.
As the embryo develops, its subsequent division occurs, as a result of which the main organs and tissues of the unborn child are gradually formed, which grow and develop over the course of 9 months.
Famous Embryologists
With the advent of the science of embryology, scientists have constantly improved and developed it. The founder of embryology is Karl Maksimovich Baer, who from early childhood showed interest in natural phenomena. He identified the main types of embryonic development and proved that all vertebrates develop according to the same principle.
Another well-known embryologist is Harvey William, the founder of modern physiology and embryology. In his works, he described the principle of systemic and pulmonary circulation.
Russian embryologist is Ilya Ilyich Mechnikov, the founder of microbiology and immunology. In his writings, he outlined the theory of immunity and the origin of multicellular organisms. Also engaged in research on aging.
