Follicular stimulation for high tech pregnancies: Are we playing it safe?

Abstract

The techniques for in vitro fertilisation have changed and improved at a great rate. The finding that the incidence of pregnancy increases in proportion to the numbers of conceptuses replaced, up to at least three, generated widespread interest in the use of follicular stimulants in the hope of obtaining many follicles and many conceptuses (or, as in the case of some units, oocytes for anonymous donation). Improvements in the efficiency of freezing techniques led to the more general use of these potent follicular stimulants, with the aim of having a stock of frozen conceptuses preserved for the couple. Almost invariably the minimum 'blanket' follicle stimulation is now provided by gonadotrophins (menotrophin), with or without an antioestrogen (clomiphene or tamoxifen). Women with ovulatory problems require more potent follicular stimulants. An outline of the development of such follicle stimulant treatments is shown in the box.