In vitro fertilisation (IVF) is a process of fertilisation in which an egg is combined with sperm in vitro. The process involves monitoring and stimulating the ovulatory process, then removing an ovum or ova from the ovaries and enabling sperm to fertilise them in a culture medium in a laboratory. After a fertilised egg (zygote) undergoes embryo culture for 2–6 days, it is transferred by catheter into the uterus, with the intention of establishing a successful pregnancy.