The importance of consistent FSH delivery in infertility treatment

The use of gonadotrophins for the treatment of infertility began in the 1930s following early work on the pituitary–ovarian axis and the discovery of FSH and LH. The technological development of pharmaceutical gonadotrophins over the last 60 years has shown improvements in specific activity, purity, degradation and detection of impurities. Throughout these pharmaceutical developments the gonadotrophin content of both urinary and recombinant preparations has been assessed using an animal in-vivo bioassay. This paper reviews the manufacturing history of recombinant human FSH (r-FSH) and follitropin-alfa filled-by-mass (FbM), and evaluates the impact of introducing a pharmaceutical product that is formulated and assayed by a physicochemical method for r-FSH protein content. This consistent gonadotrophin preparation offers the opportunity to reconsider protocols of induction in a new light, deciding the daily amount of r-FSH in relation to specific clinical parameters such as the mean ovarian volume (MOV), basal FSH concentration and body mass index (BMI). Preliminary data on the application of the formula ‘basal FSH × BMI/MOV × (5.5/75)’ gave interesting results as a new method to standardize the induction therapy. A formula is proposed for deciding the first 5 days of drug administration.