Technically, a single sperm is capable of getting a woman pregnant. However, thousands are released during each ejaculation. The sperms swim up the female genital tract to reach the fallopian tubes, where the fertilisation with the ovum occurs.
After the sperm fertilises the ovum, the zygote is formed, which slowly divides to form the embryo. The other sperms are destroyed by the female body. All men are assumed to be born with a well- functioning genital tract that starts functioning optimally after puberty. For couples having an issue with infertility, semen analysis is the first test recommended.
Wearing loose clothes and cotton undergarments and avoiding excessive heat may help improve the sperm count in individuals. Also, keep in mind that testes need a lower temperature compared to the core body temperature to perform at an optimal level.
Ultrasound zap could work as a male contraceptive.