The female partner accounts for about 60% of the causes. There are several most important aspects: first, there must be germ cells, there must be seeds, and the female partner must have normal ovulation. Secondly, this ovulation is usually normal if the menstruation is regular. If the periods are irregular, it is even possible that the ovaries are failing. Thirdly, ovulation of the ovaries is particularly related to age: ovulation starts at the age of 13 or 14; by the time she is of childbearing age, 25 to 28 is the best; from the age of 30, it starts to decline; at the age of 35, it is a very steep decline; at the age of 40, ovulation starts to be irregular, or ovulation is not good anymore. So seed is a very important factor. This is talking about the female side. Also, the fallopian tube, which picks up the eggs discharged from the ovaries, the sperm-egg has to go inside the fallopian tube to date and form a cell after fertilization. At this time both eggs are needed. After fertilization, the fertilized egg can also grow inside the uterus, so the internal environment inside the uterus, called the endometrium, the land must also be relatively fertile to work. Problems with any of these links can lead to infertility in the female partner. There are also hyperthyroidism, hypothyroidism, abnormal adrenal function, serious tuberculosis and heart disease that may affect pregnancy, which are factors of the female partner.