By In-vitro fertilization, the ovum is fertilized with sperm outside the body of a woman, providing the ovum with the same environmental conditions as it would have got inside the uterus. The zygote is grown inside a culture and when the embryo is formed, it is then implanted into the uterus where it develops into a foetus and then into a child. This is called a test-tube baby.
The methodology involves the following steps:
- Removal of the unfertilized ovum from the reproductive tract of a female.
- Ovum is kept under aseptic conditions.
- The fusion of sperm and ovum in a culture medium, outside the female body to form the zygote.
- A zygote is stimulated to develop in vitro upto 32-celled stage.
- Developing an embryo is implanted on the endometrium of the uterus at a 32-celled stage. So the pregnancy in the woman starts and further the development of the child continues in the womb till it is born.