Clinical embryology is a field 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 by all doctors.
The tasks of embryology are the timely detection of genetic abnormalities and disorders in bearing a child, the determination of diseases in children immediately after birth. To date, doctors use the available knowledge in this area to determine the causes of infertility and eliminate them, as well as to develop birth control drugs. In solving the problem of infertility, IVF, embryo transplantation into the uterus, and egg culture have gained great popularity.
History of Embryology
Like many other sciences, clinical embryology originated in antiquity. Aristotle's scientific papers contain detailed descriptions of the chicken germ. Around the same time, such points of view on development processes as epigenesis and preformism arose.
Dutchman Jan Swammerdam studied the development and metamorphosis of insects. His compatriot Anthony van Levenguk discovered parthenogenesis in aphids, studied human sperm. The Italian Marcello Malpigi investigated the development of the chicken embryo, studied the anatomical 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 embryo growth occurs. Preformist scientists thought the spontaneous generation of organisms unlikely. They believed that the embryo is located either in the ovum or in the sperm. However, they could not understand how the genetic characteristics of the second parent were transmitted to the descendants.
In the first half of the 19th century, persistent facts appeared that contradicted preformism. At that 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 studied thoroughly the embryonic development of absolutely all classes of vertebrates, the scientist found that at an early stage all the embryos are similar to each other, and differences acquire only during subsequent development. This allowed the formation of the law of germinal resemblance.
The development of this direction occurred after the research of C. Darwin. A particularly large contribution to clinical embryology was made by Soviet scientists I. I. Mechnikov and A. O. Kovalevsky.
Embryology Feature
Clinical embryology is a science that studies the development of the embryo in the mother's body or the shells of the egg. The process of fetal 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 separation;
- organ formation;
- histogenesis and organogenesis of tissues and organs of the fetus, as well as the placenta;
- the formation of body systems.
In addition, thanks to embryology, complex, critical periods of development have become known that can adversely affect the condition of the fetus under the influence of certain factors.
The subject of embryology
Modern embryology is studying the process of embryo formation. Scientists say that embryo development occurs in three main stages:
- from the moment of 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 capabilities, optimal conditions are created for the onset and normal course of pregnancy. When applying scientific data, experts will help you determine and prevent the possibility of fetal malformations in advance. Thanks to the science of embryology, scientists have identified dangerous periods of child development:
- fertilization;
- embryo implantation into the walls of the uterus;
- the formation of basic tissues;
- brain formation;
- development of organs and systems;
- birth process.
During these periods, the influence of various negative factors can provoke a slowdown, improper development, or even death of the fetus. Clinical embryology is studying the problems of deviations from the norm, and is also looking for ways to address them in order to avoid violations.
How embryologists work
Embryologist doctors deal with the problems of fertilization, and also exercise control over the development of the embryo, until the stage of its transfer 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 applied to the hospital with a problem of infertility.
With a competent approach to each couple, the doctor conducts:
- insemination - the introduction of sperm into the uterine cavity;
- assessment of sperm quality and fertilization results;
- cultivation and transplantation of embryos into the uterine cavity.
The embryologist doctor creates the most favorable conditions for the birth of a new life, helping to circumvent the barriers that prevent fertilization in vivo. A positive result is achieved through the use of modern technology.
What happens in embryology laboratories
At the Center for Embryology, a doctor examines couples to determine the causes of infertility, and then prescribes treatment. The most critical stage of IVF takes place in the laboratory, as all conditions are created that mimic the environment of the human body, fertilization and embryo cultivation are carried out.
Initially, a reproductive doctor works with the patient at the Center for Embryology, who, with the help of hormonal preparations, provokes the growth of eggs in the woman’s ovaries, monitors their growth and prepares the uterus for replanting the embryo. Using a special needle, eggs are removed from the body, which are then sent to the laboratory. In laboratory conditions, the eggs are cleaned from the outer shell to facilitate the path of the sperm, and placed in a special bowl with a nutrient medium.
After extracting the eggs, the man passes the sperm, which also undergoes special processing. As a result of this, the most motile sperm are selected. Then, active sperm are transferred to the egg cell; from this moment, the fertilization procedure begins. After a day, the nutrient medium for the zygote is replaced with a fresh one. The doctor monitors the embryos for 4-5 days, and then plants them into the woman's body.
What is the embryological protocol?
Information about the fertilization carried out 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 gives preliminary information regarding the number of fertilized eggs. The documentation indicates data regarding the thickness of the membrane formed around the embryo, fragmentation and ordering of the arrangement of cells.
Embryo developmental stages
The process of fertilization is very complex and involves the fusion of female and male germ cells, during which there is a restoration of the set of chromosomes and a new fertilized egg is formed. Fertilization occurs in the fallopian tubes, by the fusion of sperm and egg cells.
After fertilization within 12 hours, a zygote is formed in the body of a woman. After a few days, zygote division occurs, then two blastomeres are formed, one of which is distinguished by larger sizes and a darker shade. From a larger part, an embryo, placenta, and other tissues are formed. The embryo invades the uterine mucosa.
As the embryo develops, its subsequent division occurs, as a result of which the main organs and tissues of the unborn child gradually form, which grow and develop over 9 months.
Famous embryologists
With the advent of the science of embryology, scientists have constantly improved and developed it. The founder of embryology is considered to be Karl Maksimovich, who from an early age showed interest in natural phenomena. He identified the main types of embryonic development and proved that all vertebrates develop according to a single principle.
Another famous embryologist is
Harvey William, the founder of modern physiology and embryology. In his works, he described the principle of a large and small circle of blood circulation.
The 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. He also studied aging.