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IVF treatment. Light micrograph of a micro-needle (right) injecting human sperm into a human egg cell This technique used for in vitro fertilisation (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 patient's 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. Magnification: x590 when printed at 10 centimetres wide. (KEYSTONE/SCIENCE PHOTO LIBRARY/AJ PHOTO/SCIENCE PHOTO LIBRARY)