The process whereby the initial stages of procreation are produced outside the human body and completed in the uterus or womb. The procedure is also known as ‘embryo transplantation’ and ‘in vitro fertilisation’ (IVF). It consists of extracting an ovum (or egg) from the prospective mother's body and placing this in a dish where it is mixed with the male partner's SEMEN and nutrient fluids. After the ovum is fertilised by the sperm it is transferred to another dish containing a special nutrient solution. Here it is left for several days while the normal early stages of development (see FETUS) take place. The early EMBRYO, as it has then become, is implanted in the mother's uterus, where it ‘takes root’ and develops as a normal fetus.

Embryo transplantation and research are procedures which raise ethical and moral issues, so in many countries are controlled by legislation. In the UK, embryo transfer and research using embryos are regulated by the HUMAN FERTILISATION & EMBRYOLOGY AUTHORITY (HFEA). (See also ASSISTED CONCEPTION.)