In vitro fertilisation (IVF), illustration. A micro-needle (top) injecting human sperm into a human egg cell. This technique used in IVF is known as intracytoplasmic sperm injection (ICSI). The injected sperm fertilises the egg. The resulting zygote is then grown in the lab until it reaches an early stage of embryonic development. It is then implanted in the uterus. Several embryos are usually implanted to give the greatest chance of a successful pregnancy. However, this can result in multiple births. IVF allows infertile couples to conceive a child.