During the natural process, 1 or 2 eggs (oocytes) are released from the ovaries into the abdominal cavity in the middle of the menstrual period of a woman with a regular menstrual cycle. While the egg, which is captured by an organ called the uterine tube moves towards uterus, it meets with the sperm ascending through vagina that was deposited during sexual intercourse and after this meeting fertilization takes place in the tube. The fertilized egg, which is directed towards the uterus spends 3-4 days during its trip inside the tube and reaches the uterus around the 5th day and settles there. By this way, pregnancy starts. The causes affecting any step of this process leads to impairment of fertility generating the phenomenon known as infertility. Infertility is failure of conceivement despite unprotected and regular sexual intercourse for 6 months -1 year. Approximately 15% of the couples, in other words 1 out of 6 couples, experience this problem at any stage of their reproductive life. Causes of infertility seem to be equal by 40% for both sexes. In 10-15% of the couples, there is not any significant disorder. At the end of the examination tests applied to the partners the type of the treatment is determined.

These tests are;

Gynecological and ultra-sonographic examinations during menstrual period and hormone
analysis (FSH, LH, E2, PRL, TSH, FT4), Uterine x-ray, sperm analysis (spermogram)
In-vitro fertilization (IVF) is fertilization of the egg with the sperm outside the body in a laboratory environment. In conventional methods, namely in the classical in-vitro fertilization, the egg is fertilized by adding a certain number of sperm in a laboratory dish.

In the microinjection method, each egg is fertilized by a single sperm one by one. A variety of factors affecting interaction of the sperm and egg create the necessity of in vitro fertilization.