1. Female age is the most important factor affecting fertility The best age for women to have children is 25-29 years old; after 30 years old, female fertility starts to decline; after 35 years old, female fertility declines linearly; and after 40 years old, women gradually enter the perimenopausal period, and there are few successful pregnancies. In the treatment of infertility, there is a direct relationship between the age of consultation and the outcome of infertility treatment. Even in IVF treatment, the chances of a successful pregnancy are greater when the woman is younger than 35 years old. Therefore, if infertility is detected, it is best to seek treatment before the age of 35. However, younger women should pay attention to the age of their ovaries. In some women, although they are very young, the ovarian function has already started to decay, and the age of the ovaries in their 20s is already equivalent to that of a 40-year-old near-menopausal condition, and it is more difficult to treat such infertility patients. Therefore, treatment of infertility should be taken urgently and should not be procrastinated. 2, the birth of deformed children and age-related The incidence of fetal malformations in women over 35 years of age is increasing situation. Studies have shown that the incidence of congenital infantile malformations is only 1/1500 among women aged 25-29, 1/900 among women aged 30-34, 1/300 among women aged 35-39, and 1/40 among women aged 45 and above. For men, age is also closely related to sperm quality and the health of infants. 25-35 year old men have the best sperm quality, and after 40 years old, sperm quality gradually decreases. Sperm quality decreases after the age of 40. Sperm chromosomal abnormalities in men increase with age, and the number of children with abnormalities doubles if the father is over 40 years old.