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IVF treatment. Coloured light micrograph of a micro-needle (left) injecting human sperm into a human egg cell (centre) being held in place by a pipette (right). This technique, known as intracytoplasmic sperm injection (ICSI), is used in IVF (in vitro fertilisation) treatment and allows infertile couples to conceive a child. The injected sperm fertilises the egg, which is then grown in the lab until it reaches an early stage of embryonic development. The embryo is then implanted into the patient's uterus. Several embryos are usually implanted to give the greatest chance of a successful pregnancy, but this can sometimes lead to multiple births. Image 2 of 2: see M802/304 for image 1 of 2. (KEYSTONE/SCIENCE PHOTO LIBRARY/ZEPHYR/SCIENCE PHOTO LIBRARY)