Egg fertilization process

Only when the egg and sperm combine can new life be conceived. Human reproduction is inseparable from the egg. It is also a cell unique to females that can give birth to new life. Do you know about the egg fertilization process? Generally, male sperm will survive in the female body for 48 hours. If the woman ovulates at this time, the sperm and egg can combine well, and the woman will successfully become pregnant. The process of life is really magical.

In fact, there are only 300 to 400 mature eggs in a woman's lifetime, and the rest are left to fend for themselves. An egg released by a woman can survive for 48 hours. If sperm comes within these 48 hours, the woman can become pregnant. This is the process of egg fertilization.

Eggs are produced by the female gonads we usually call the ovaries. The largest cells in the human body, mature follicles are about 18mm in diameter. The main function of the ovaries, in addition to secreting essential sex hormones for women, is to produce eggs. The rudiments of the ovaries are formed in girls during the embryonic period of about 3-6 weeks of gestation. Before birth, millions of oocytes are formed in the ovaries. After childhood and adolescence, only about 100,000 oocytes remain by adulthood. The oocyte is wrapped in a primordial follicle. Under the influence of sex hormones, only one primordial follicle matures every month, and the mature egg is then discharged from the ovary into the abdominal cavity.

Generally speaking, a woman will produce about 300-400 mature eggs in her lifetime, and the rest of the oocytes will die on their own.

An egg can survive for about 48 hours after being released, waiting to meet and combine with sperm during these 48 hours. If the egg cannot meet the sperm to form a fertilized egg due to various reasons after being released, it will die naturally after 48-72 hours. If you miss the chance of fertilization this time, you will have to wait until another egg matures and is released one month later, and then repeat the same process. The left and right ovaries usually ovulate alternately, but in rare cases two or more eggs can be released at the same time. If they combine with sperm separately, dizygotic twins and fraternal twins will appear.

Among the causes of female infertility, infertility caused by ovarian factors accounts for about 15%-25% of infertility. Ovarian anovulation is one of the important reasons.

During the fertilization process, sperm needs to go through a "long journey" to complete the "kiss of life" with the egg to achieve the purpose of pregnancy. Sperm is ejaculated into the vagina along with semen, passes through the cervix and uterus to reach the fallopian tube, and combines with the egg to form a fertilized egg. The smooth progress of this process is closely related to the activity of sperm and the physiological conditions of the female reproductive tract.

Sperm enters the vagina: After semen is ejaculated into the vagina during sexual intercourse, most of it accumulates in the posterior fornix of the vagina, and the cervical opening is immersed in this pool of semen. Under normal circumstances, sperm can enter the cervical canal after a few minutes. The normal vaginal environment is acidic, which has important physiological significance for the self-cleaning function of the vagina, but is not conducive to the activity and survival of sperm. However, the seminal plasma, which is a mixture of secretions from the epididymis, seminal vesicles, prostate and bulbourethral glands, is alkaline and can dilute and neutralize the acidic fluid in the vagina. In addition, during sexual intercourse, the alkaline cervical secretions increase, which can make the area around the cervical opening become neutral or alkaline. All of these create conditions for sperm to survive and move in the vagina.

The process of sperm passing through the fallopian tube: Sperm moves in the fallopian tube mainly through the brief segmented contraction of the fallopian tube muscle wall, which causes the sperm and tubal fluid to flow to the ampulla of the fallopian tube. The fallopian tube epithelial cells have countless cilia, which swing from the fimbria toward the uterine cavity. After the egg escapes from the ruptured mature follicle, it is captured by the fimbria of the fallopian tube. The egg has no motility and its movement depends on the contraction of the fallopian tube smooth muscle and the cilia movement of the epithelium. It moves slowly and passively toward the uterine cavity, where it combines with the sperm swimming upstream and is fertilized. The fertilized egg passively moves into the uterine cavity and implants in the endometrium, and a new life begins.

A man's sperm can survive in a woman's body for several days, but a woman's egg can only survive for one day. Many times, women cannot judge their ovulation time well, and therefore cannot successfully become pregnant. Everyone should know more about the egg fertilization process, which will also help increase the chances of conception for couples. Give birth to new life as soon as possible.