Puberty is the stage when the reproductive organs have developed and attained maturity. There are four reproductive events which occur after puberty. The four events are gametogenesis, fertilization, implantation and parturition. Gametogenesis is the formation of gametes. In males, this process is called spermatogenesis and in females, oogenesis. fertilization is the fusion of gametes. Implantation is the attachment of the foetus to the uterus. parturition is the process of childbirth.