The process of combining sperm and egg is called fertilization or conception, and conception is the beginning of pregnancy.
During sexual intercourse, a man discharges about 200-400 million sperm each time. Most of the sperm are discharged from the vagina with the semen. A small number of sperm advance by the swing of the tail and pass through the cervix. tube, the uterine cavity, and finally reaches the terminal point – the ampulla of the fallopian tube, where it waits for fertilization with the egg. The fastest time for sperm to reach the fallopian tube from the vagina is only a few minutes, up to 4-6 hours, and generally 1-1.5 hours. As the sperm advance, they are blocked by cervical mucus and engulfed by white blood cells in the uterine cavity. Only dozens to one or two hundred sperm finally reach the fallopian tube. Before the sperm can fertilize the egg, it needs to be incubated for a period of time in the female reproductive cavity before it has the ability to fertilize. This process is called sperm capacitation.
When a woman is of childbearing age, her ovaries release one mature egg every month, and the ovulation date is about 14 days before the next menstrual period. After the egg is discharged from the ovary, it is immediately sucked into the fallopian tube by the fimbriae of the fallopian tube and waits for the arrival of sperm in the ampulla of the fallopian tube.
Sperm can survive in the female fallopian tube for 1-3 days, and eggs can survive for about 1 day. If a woman has sexual intercourse within a few days before and after ovulation, sperm and eggs may meet in the ampulla of the fallopian tube. At this time, a group of sperm Surrounding the egg, the head of the capacitated sperm secretes acrosome enzyme to dissolve the corona radiata and zona pellucida around the egg, opening the way for the sperm to enter the egg. Finally, only one sperm enters the egg, and then forms a new cell. This cell is called a fertilized egg, and this process is called fertilization.
The fertilized egg absorbs nutrients and oxygen from the fluid secreted by the fallopian tube and continues to divide. At the same time, the fertilized egg gradually moves toward the uterine cavity. When it reaches the uterine cavity 3-4 days later, it has developed into an entity with multiple cells, shaped like a morula, so it is called a morula. The morula continues cell division in the uterine cavity to form a blastocyst, which enters the endometrium approximately 6-8 days after fertilization. This process is called implantation.
After implantation, the fertilized egg gradually develops in the uterine cavity. After 5-8 weeks of menopause, the fertilized egg develops into an embryo and develops into a fetus after 9 weeks.
Conception is a relatively complicated process. To complete this process, both couples must have certain fertility conditions. These fertility conditions can be roughly divided into the following aspects:
1. Men’s testicles can produce normal sperm
The amount of semen ejaculated by a normal adult man at one time is 2-6 ml. The number of sperm in each ml of semen should be Above 60 million, more than 60% of sperm are motile and less than 30% are abnormal sperm. If the sperm does not meet the above standards, it will not be easy for the woman to get pregnant.
2. Women’s ovaries can release healthy and mature eggs
Women with normal menstruation will have a healthy and mature egg in each menstrual cycle. The eggs are released, so that there is a chance of pregnancy. For women who do not ovulate due to ovarian insufficiency or abnormal menstruation, it is not easy to conceive.
3. Women have normal sexual life before and after ovulation
Sperm can survive in the female vagina for 1-3 days, and eggs can survive for about 1 day after ovulation. Women The ovulation time is about 14 days before the next menstrual period, and the possibility of pregnancy through sexual intercourse within a few days before and after ovulation is relatively high.
4. The reproductive tract must be unobstructed
The male\’s vas deferens must be unobstructed so that sperm can be discharged through normal sexual life and enter the female reproductive tract to combine with eggs. The female reproductive tract must also be unobstructed , so that the sperm that enters the vagina during sexual intercourse can pass through the cervix, uterus, and reach the fallopian tube without any obstruction to meet the egg for fertilization. The fertilized egg can also enter the uterine cavity smoothly. If the fallopian tube is blocked, the sperm and egg will be lost. The chance of union, so once the fallopian tube is blocked, the chance of natural conception is completely lost.
5. In utero The environment is suitable for the implantation and development of the fertilized egg
After the egg is fertilized in the ampulla of the fallopian tube, it moves toward the uterus through the fallopian tube as it develops. It reaches the uterine cavity in 3-4 days and reaches the uterine cavity in 6-8 days. It is buried in the nutrient-rich endometrium and then continues to develop into a fetus. The development of the fertilized egg and the growth of the endometrium proceed simultaneously. If the fertilized egg enters the uterine cavity early or late, the endometrium at this time will not be suitable for the fertilized egg. Implantation and continued development will make it impossible to become pregnant.
This article is provided by Baidu Reading and is excerpted from \”The Complete Pregnancy Plan for Expectant Fathers\” Author: Wang Yanqin