Physiological Mechanism of Aging Fertility
With the progress of society and the change of people's ideas, more and more women choose to postpone childbearing. However, the aging of fertility has also brought about a series of changes in physiological mechanisms. This article will elaborate on the physiological mechanism of aging fertility from four aspects: the decline of egg quality, the lengthening of menstrual cycle, the reduction of follicular development and the change of uterine environment.
Egg quality decline
The decline of egg quality is a major physiological mechanism of aging fertility. With the growth of women's age, the quality of eggs gradually declined. This is because the number of female eggs at birth is fixed. With the growth of age, the number of eggs is decreasing, making the remaining eggs aging. At the same time, the decline of egg quality is also related to mitochondrial dysfunction, nuclear variation and other factors in the follicle. This will affect the fertilization ability and implantation ability of the egg, as well as the quality of embryonic development.
Affected by age, the quality of follicles in elderly women decreases, and the proportion of high-quality eggs also decreases accordingly. This increases the difficulty of pregnancy. In addition, due to the decline in egg quality, the risk of miscarriage and chromosomal abnormalities in elderly women is also significantly increased.
Longer menstrual cycle
Another physiological mechanism of aging fertility is the lengthening of menstrual cycle. Under normal circumstances, women's menstrual cycle is about 28 days. However, the menstrual cycle tends to lengthen with age. This is mainly related to the long time of follicular development and the delayed ovulation of follicles. Due to the prolongation of follicular development time, the ovulation time of eggs is also postponed, resulting in a longer menstrual cycle.
The longer menstrual cycle will further affect the fertility of elderly women. Irregular menstrual cycle and delayed ovulation time will make it difficult for older women to accurately grasp the best pregnancy time. At the same time, the longer menstrual cycle also increases the possibility of egg aging and reduces the success rate of pregnancy.
Decreased follicular development
With the increase of age, the number of follicles in elderly women gradually decreases. In the first cycle after menstruation, women usually have 10-20 follicles, but when they are over 35 years old, the number of follicles decreases significantly. This is because women's eggs are formed at birth. The older they are, the fewer eggs they have.
The reduction of the number of follicles will further affect the fertility of elderly women. Follicles are not only responsible for the development and maturation of eggs, but also produce female hormones. The reduction of follicular development will lead to changes in hormone levels, which will affect the growth and maturation of endometrium, making implantation more difficult.
Changes in uterine environment
Another physiological mechanism of aging fertility is the change of uterine environment. Endometrium is an important place for embryo implantation. Its thickness, texture and blood supply will affect the growth and development of embryos.
With the increase of age, the thickness of endometrium and blood supply will gradually decrease, which will affect the implantation ability of embryos. In addition, the texture of the endometrium will also change and become more relaxed, making it difficult for the embryo to be implanted.
Summary
The physiological mechanism of aging fertility mainly includes the decrease of egg quality, the lengthening of menstrual cycle, the decrease of follicle development and the change of uterine environment. The decline of egg quality leads to the decline of fertility and embryo quality, which increases the risk of abortion and chromosomal abnormalities. The longer menstrual cycle makes it difficult for older women to grasp the best time to conceive, and increases the possibility of aging eggs. The decrease of follicle development leads to the change of hormone level, which affects the growth and maturity of endometrium, and makes implantation more difficult. At the same time, changes in the thickness and texture of the endometrium also limit the growth and development of the embryo.
Therefore, it is very important for elderly women to understand the physiological mechanism of fertility for them to choose the time of childbirth and adopt corresponding assisted reproductive technology.
