In vitro fertilisation. Light micrograph of a micro-needle (right) that is being used to inject a human sperm cell into a human egg cell. The tip of a micro-pipette (left) is holding the egg cell in place. This in vitro fertilisation (IVF) technique is known as intracytoplasmic sperm injection (ICSI). The injected sperm fertilises the egg and the resulting zygote is then grown in the laboratory until it reaches an early stage of embryonic development. It is then implanted in the patient's uterus, where it develops into a foetus. IVF allows infertile couples to conceive a child.