Women are born with eggs that have life, and these eggs age along with it. Menopause (average 51 years) is when the body no longer left to be ovulated eggs, and therefore, the menstrual period.
The ability to get pregnant decreases with age. Although most women have regular periods in the years before menopause, pregnancy risk is extremely low. In fact, the possibility of pregnancy is only 5% per month at age 40.
There are two main features of reproductive aging in women – decrease in the number of eggs and decreased egg quality. During the life of a woman, most of the eggs continuously die by a process called atresia. The factors determining the rate of atresia are unknown; However, this constant is independent lifestyle, hormonal influences (birth), and pregnancy. When the number drops too low, ovulation ceases and menopause occurs.
Regarding fertility, the most critical effect of aging is a decrease in egg quality. As women enter their late 30s and early 40s, most of the ovulated eggs are genetically abnormal. As a result, when these eggs fertilized, is likely to result in embryos that contain genetic abnormalities that are not healthy enough to implement and cause pregnancy. Moreover, even when they do implant, the possibility that a miscarriage occurs is high, rising steadily with advancing maternal age.
The most convincing in the role of egg quality with infertility test lies in the results of the in vitro fertilization (IVF) treatments with donor eggs. In this case, the eggs of a woman in her 20s is implanted into the patient. Pregnancy and live birth rates are extremely high after egg donation (50% probability of live birth), and correlated with the age of the egg donor rather than the recipient. This example demonstrates how success in fertility treatments is driven largely by maternal age.
Women seeking pregnancy after age 35 must follow a fertility evaluation if they are unable to conceive after six months. Any anomaly present should be addressed, possibly with targeted therapies. The fertility evaluation page explains what tests are needed and how to program such appointment.