In vitro fertilization. Image 2 of 4. Computer artwork of an egg cell (centre) into which a sperm cell was injected during in vitro fertilization (IVF). The injected sperm cell has fertilized the egg cell to form a zygote. The genetic material of each cell will merge to form a complete set needed for a new human. The cell will then divide into a ball of cells in the early stages of embryonic development. It is then placed in the uterine wall, allowing pregnancy to proceed as normal. IVF treatment enables couples with any of a range of infertility problems to conceive a child. For a sequence showing the development of an embryo from IVF treatment, see images M802/237-240.