In Vitro Fertilization and Embryo Transfer
When the union between egg cell and sperm occurs outside the body in a culture vessel, it is known as in vitro fertilization. This involves collection of healthy ova and sperms from healthy females and males, respectively, and their fusion under appropriate conditions in vitro.

The resulting zygotes may be cultured in vitro for a period of time to obtain young embryos, which ultimately are implanted in the uterus of healthy females to complete their development.