The process of conception, sexual intercourse after semen accumulated in the vagina semen, there are a large number of sperm, sperm survival time is about 72 hours, the activity of sperm through the uterus to the ampulla of fallopian tube and the egg, fertilization, zygote by tubal transport to the uterine cavity in the uterine cavity, and "roam" 2~3 day, looking for the right, and then implantation, growth until term delivery in uterine cavity. The following is an indispensable process in the process of conception.

1、Men's testicles produce normal sperm. The amount of semen ejaculated by a normal adult male is 2 - 6 ml. the number of sperm per milliliter of semen should be above 60 million, with more than 60% of the active sperm and less than 30% of the abnormal sperm. If the sperm does not meet the above standards, it is not easy to make the woman pregnant.

2、The female ovaries expel healthy mature eggs. Women with normal menstruation have a healthy, mature egg every menstrual cycle, so they have the chance to get pregnant. Women who do not ovulate because of ovarian dysfunction or irregular menstruation are less likely to conceive.

3、Normal sexual life should be maintained before and after ovulation, so that sperm and eggs have the opportunity to meet and fertilize. The sperm in the female vagina can survive 1 to 3 days, the egg can survive for 1 days, ovulation time in 14 days before the next menstruation, ovulation in the possibility of a few days before and after sexual intercourse before pregnancy. Intercourse during ovulation is not pregnant.

4、The reproductive tract must be unobstructed. The vas deferens male sperm must be smooth, can through the normal life and discharged into the female reproductive tract and egg. The female reproductive tract must also be unobstructed, so that during intercourse, the sperm entering the vagina can pass through the cervix, uterus, fallopian tube and ovum without any obstruction. The fertilized egg can also smoothly enter the uterine cavity. If the fallopian tube is blocked, the sperm and the egg lose the opportunity to combine, so once the fallopian tube is blocked, it completely loses the natural conception.

5、The intrauterine environment must be suitable for fertilization, implantation, and development. The egg in the ampulla of fallopian tube after fertilization, while the development side of the fallopian tube to the uterus moving direction, 3 - 4 days after the arrival of uterine cavity, 6 - 8 days buried in nutrient rich endometrium, and to develop into a fetus. It's impossible to conceive.

6、Under normal physiological conditions of cohabiting couples, did not take contraceptive measures, every month the chance of pregnancy was 20%, the first half of the chance of pregnancy for 70% years, a chance of pregnancy was 80%, if more than one year did not take contraceptive measures and infertile medical examination. However, there is no need to be too nervous. A couple can get what they want if they don't have any fertility problems.