Since the introduction of the first recombinant human follicle stimulating hormone (FSH) preparation Gonal-f in the year 1996, a pure drug is available as raw material, which is independent of human urine due to biotechnological methods and consequently can be produced free of contaminating proteins. In accordance with the recommendations of European Medicines Agency (EMEA) in February 1999, on the basis of data from clinical studies, Gonal-f should be regarded as the more effective preparation in comparison to urinary FSH. Serono has developed a dose calculator, the CONSORT calculator, after analyzing the data from clinical studies for Gonal-f. This non-interventional study is planned to examine the consistency of the dose recommended by the doctor for the first stimulation day with the dose recommended by the CONSORT calculator. All subjects, who undergo stimulation with Gonal-f in preparation for a technology of the assisted conception in accordance with the permitted indication, will be included in this non-interventional study.