In vitro fertilisation (IVF) refers to a reproductive medical technique that involves the fertilisation of an egg cell as part of an infertility treatment outside the body. For this purpose, oocytes are aspirated from the ovaries after hormonal stimulation. The procedure and the hormonal treatment are a significant burden for the woman whose oocytes are taken.

Sperm cells are obtained by ejaculation and processed. The egg and sperm cells are brought together in the test tube, then, the fertilisation takes place. The resulting zygote develops in vitro the same way as an early embryo in vivo.

Through IVF, not only own egg cells, but also foreign egg cells by donors can be fertilized and implanted. In this way women can get pregnant despite maternal infertility and a selection concerning certain hereditary features is possible without a PGD.

In different countries, the permissibility of such a selection is regulated in various degrees. Thus, under British law only medical information, especially with regard to possible hereditary diseases, may be taken into account, whereas in some states of the United States, non-medical information, such as the donor's social origin, may also be included in the donor egg selection process. Furthermore, in contrast to the United States, the commercialisation of egg donation in the UK is prohibited by law, and children born after IVF have a right to get information about their origin after they turn 18 years old. These differences in admissibility mean that British women increasingly travel to the US for IVF treatment and use the services of IVF institutions there.