IVF, IVM, natural cycle IVF, minimal stimulation IVF - time for a rethink.

Considerable changes are afoot in the practice of assisted human conception. Doubts about its methods, especially over endocrinology, concern its complexity and its expense. IVF has spread worldwide since its beginnings in the UK, but its current practice, termed routine IVF, is being challenged by simpler routines. These include natural cycle IVF, which has been in the background for many years, minimal stimulation IVF, where doses of hormones are reduced, and the in-vitro maturation of human oocytes ready for fertilization in vitro (IVM). These three approaches are now practised in increasing numbers of IVF clinics, and may well replace routine IVF. The events leading to current interest in these methods will be discussed briefly in this review.