Purpose of the study is the comparative evaluation of the clinical efficacy and of the general tolerability of two different subcutaneous FSH preparations (Fostimon® IBSA Vs Gonal-F® Serono) when administered in patients undergoing ICSI

This is a multicentric, prospective, randomised, investigator blind, controlled clinical trial (phase III) of two parallel groups, one receiving the test drug FSH (Fostimon® , IBSA) and the other the reference drug FSH (Gonal-F®, Serono). The groups will be paired on the major prognostic criteria.

In effect, a double blind trial is not really feasible since the drugs presentations are very different. However, in IVF, drugs are usually dispensed and/or injected by a nurse and therefor the Investigator can be blind. Moreover, the used preparations will contain the same amount of gonadotrophin units (75 IU), will be repackaged in anonymous boxes and the following sentence will be written in the Patient Information Sheet: "You are required not to inform the Investigator about the product's name".

The randomisation is necessary to get groups as comparable as possible for all the other aspects. The multicentric design has the double interest of facilitating the patients' recruitment and of decreasing the biases related to attitudes in a specific centre.

Inclusion Criteria:

Women undergoing ovarian stimulation for IntraCytoplasmic Sperm Injection (ICSI) with the following characteristics:

>/= 18 and < 40 years old BMI between 19 and 30 kg/m2 less than 3 previous completed cycles basal FSH level less than 10 IU/l within the 6 months prior to the study

Exclusion Criteria:

age < 18 and >/= 40 years primary ovarian failure or women known as poor responders, i.e. requiring more than 225 IU of FSH as starting dose in previous treatment cycles or having less than 3 oocytes retrieved or with an oestradiol serum concentration < 900 pmol/l (250 pg/ml) ovarian cysts > 20 mm oocyte donation thawed embryos replacement patients affected by pathologies associated with any contraindication of being pregnant ascertained or presumptive hypersensitivity to the active principle and/or their ingredients abnormal bleeding of undetermined origin uncontrolled thyroid or adrenal dysfunction neoplasias severe impairment of the renal and/or hepatic functions women deprived of their freedom by administrative or legal decision