IVF and ET refers to in vitro fertilisation and embryo transfer. In hygenic condition gametes from the male and female are collected and induced to fuse in the laboratory. That is set up under simulated conditions.
The formed zygote is collected and is introduced into the uterus of a host or surrogate mother at an appropriate time (secretory phase). Early embryos (up to 8 cell) are generally transferred to the fallopian tube whereas embryos with more than 8 cells are transferred to the uterus.