>>11011620Because the “hairs” lining the inside of the reproductive tract are mostly intact. The sperm cells themselves cant swim to the fallopian tubes, the uterus has to physically transport them there.
As the cells age and divide, the “hairs” become more and more corrupted, and, reducing the mobility of sperm. In most cases, menopause hits before the transport mechanism becomes useless, but not always. A lot of the time, when a woman becomes infertile before menopause, its because of the degrading transport tissues.
