Pregnancy at the age of 40 belongs to the senior pregnant women, the incidence of miscarriage, preterm labor, fetal malformation and difficult labor will increase. Premature labor and miscarriage are more likely to occur in older pregnant women than in the general population. Due to the increase in age, the resistance of older pregnant women and the body’s ability to compensate for this weaken accordingly, and thus they are more likely to have miscarriages or premature births than younger pregnant women. Older pregnant women are also susceptible to chromosomal abnormalities because the quality of the egg decreases with age, and chromosomal segregation may occur during the process of combining with sperm to form a fertilized egg, increasing the possibility of genetic diseases such as Down’s Syndrome. In addition, the contractile capacity of the birth canal and pelvis of pregnant women of advanced age is also reduced, and the ability of the vagina and uterus to stretch is reduced, which may lead to obstructed labor and so on. Therefore, for women over 35 years old, they need to consider carefully before having children, and it is recommended to do prenatal counseling and examination, and during pregnancy, they need to do regular maternity checkups, develop good living habits under the guidance of the doctor, and seek medical attention in case of any discomforts.