FOLLICULOGENESIS - THE NATURAL WAY

Natural cycle IVF (NIVF) arose from a wish to understand intrafollicul ar events in couples with unexplained infertility. Single follicle asp iration required unusual technical skill and a precise understanding o f the endocrinology in the ostensibly normal cycle. The application of NIVF to all candidates for assisted conception resulted in a low deli very rate. However once data had accumulated it became apparent that a ge, follicular phase FSH concentrations and other endocrine abnormalit ies were associated with high failure rates. The concept of using NIVF as a preliminary screening cycle arose. By early elimination of some candidates and selective inclusion of others a highly cost effective r egime can be developed. Taking delivery rates into account the cost pe r maternity is only half that of stimulated IVF. Using clear cut algor ithms for the investigation of different categories of infertility the place of NIVF can be defined. Current UK discussions relate to exclus ions from access to IVF. Biological exclusions such as age could furth er enhance the cost effectiveness of NIVF. When NIVF can contribute to at least 50% of cycles in an assisted conception programme it has the potential to have a major economic impact.