Fertilization of the egg is the moment of the birth of a new life, the meeting of two cells from which a person will develop. This process - complex and surprising, thought out by nature - is of great interest for both scientists and future parents.
Where the egg is fertilized
Fertilization of the egg occurs, as a rule, in the fallopian tubes, which lead from the uterus to the ovaries. It is from the ovaries that the maternal egg leaves and meets the spermatozoon. After the zygote descends into the uterus and looks for a place to attach, where it will develop for the next nine months.
Stages of oocyte fertilization
Fertilization of the egg can occur, on average, once a month. But how do you know when an egg is ready for fertilization? If the cycle is stable, the monthly ones arrive on time and last approximately the same number of days, then it is not difficult to calculate the fertilization of an egg by day. As a rule, the cell is ready for the birth of a new life 14 days before the end of the cycle. This is how much the second phase of the menstrual cycle lasts. The first phase varies depending on the characteristics of the hormonal system, and can last from 7 to 16 days or more.
However, in some women the cycle is unstable, and therefore the time of fertilization of an oocyte can occur at any time. The ability of the ovum to fertilize is maintained for 12 to 48 hours. Spermatozoa can live in the genital tract for up to 5-7 days, due to this the probability of getting pregnant in each cycle is high even with rare sexual acts.
It is difficult to say exactly how long the fertilization of an ovum lasts. The rate of movement of spermatozoa along the genital tracts is 2 centimeters per hour, but the egg may not yet be ready by the time they reach its location. Therefore, the period of fertilization of the egg is sufficiently stretched in time - from sexual intercourse to confluence can take from three hours to several days. All this time the body will be waiting for a signal for fertilization. If this does not happen, the cycle will end, the menstruation will come and the process will be restarted.
Exceptional cases
In some cases, the next cycle of a woman ripens not one egg, but two. In this case, the fertilization of two eggs is possible, and the result of pregnancy will be the birth of twins, such twins are called raznoyaytsevymi. They can have different sexes and not be so similar to each other as monotonous. Less often the ovaries release 3-4 and even more mature eggs.
In addition, there is an artificial insemination of the egg (IVF). In this case, the fertilization of an egg with a sperm occurs in a test tube, and after zygote is inserted into the body of a mother or a woman willing to bear a child for a couple. As a rule, IVF procedure uses several fertilized eggs at once to increase the probability of successful outcome. To find out, through how many fertilization of an egg occurs in this case it is possible to within hours and minutes.
What happens after the fertilization of the egg
After the fertilization of the egg begins a long process of its development. The cells begin to divide, two are born from four, then there are eight and so on. Within a few weeks, the small embryo will begin to pulsate with the aorta, the main organs will be laid, hands and feet will form. Since the moment of fertilization in the zygote already
However, along with the ovum, the entire maternal organism passes a huge path of development. The hormonal status, chemical reactions, the uterus is being prepared for implantation of the egg, which will happen in 1-2 weeks and will last up to two days. Very soon the future mother will feel these changes herself - the state of health, mood, appetite will change, and pregnancy can be confirmed with medical tests. In 7-8 weeks after fertilization the baby can be seen on ultrasound, it will be his very first photo.