Immunogenicity of Repeated Follicle Stimulating Hormone (FSH) Stimulation Cycles

Inclusion Criteria: * Healthy female volunteers undergoing controlled ovarian hyperstimulation for oocyte donation with the following characteristics: * Able and willing to sign the Subject Consent Form and adhere to the study visit schedule; * \>=18 and \<35 years old; * Regular menstrual cycle (26 - 35 days); * BMI between 18 and 30 kg/m2; * First gonadotrophin treatment (i.e. naïve Subjects with regard to exposure to human derived or recombinant gonadotrophins); * basal FSH \<10 IU/L and E2 \<80 pg/ml (\~290 pmol/l); * Normal TSH levels; * Willing to perform at least two consecutive oocyte retrieval cycles (with a wash out period of two months). Exclusion Criteria: * Age \<18 and \>=35 years; * PCOS; * Endometriosis; * Subjects with evidences of autoimmune or rheumatic diseases; * Hypersensitivity to the active substance or to any of the excipients (lactose); * Abnormal bleeding of undetermined origin; * Subject found to be positive to anti-TSH antibodies (i.e. suffering from thyroidal diseases); * Uncontrolled adrenal dysfunction; * Neoplasia; * Severe impairment of renal and/or hepatic function; * Use of concomitant medications that might interfere with study evaluations (e.g. immunosuppressant, non-study hormonal medications, therapeutics proteins like insulin, growth hormone…).