Tailoring FSH and LH administration to individual patients.

Many clinical trials have been carried out to find the optimal gonadotrophin starting dose for IVF. The consensus for patients undergoing first treatment and <40 years old is a range stretching from 150 to 250 IU/day. The varying ovarian response to gonadotrophins may be due to factors such as age, basal FSH, number of antral follicles and body mass index, all of which should be taken into account before choosing the type of protocol and the amount of gonadotrophins to use. Increasing the dose of recombinant FSH does not compensate for the age-related decline in retrievable oocytes. Higher doses of gonadotrophins are required in overweight patients, but enhanced protocols are thought to only marginally improve live birth rates in obese women. The actual role of LH in controlled ovarian stimulation is still a matter of debate. A therapeutic 'window' of LH concentrations, below which oestradiol production is inadequate and above which LH may be detrimental to follicular development has been described.