After a brief historical survey and review of the main Swiss centres engaged in medically assisted procreation, the indications for in vitro fertilization and embryo transfer (IVF-ET) are discussed. This technique offers the sterility specialist a new approach in allowing separate investigation of the two gametes and study of their interactions. This therapeutic approach to infertility is thus supplemented by biological data which may modify or highlight some of the etiologic aspects and promote new treatments. The techniques employed at our centre and the results obtained over the past four years are presented. Analysis of IVF pregnancies shows that the obstetric risks can be associated with the characteristics of the groups treated rather than with the IVF technique.