A Randomised Trial Comparing the Ovarian Response of a Starting Dose of Either 10 μg or 15 μg Follitropin Delta (FE 999049) to a Starting Dose of Either 150 IU or 225 IU Follitropin Alfa (GONAL-F) in Conventional Regimens in China

Inclusion Criteria: * Signed and dated Informed Consent Form for participation in the trial, obtained before any trial-related procedures. * In good physical and mental health in the judgement of the investigator. * Chinese pre-menopausal female between the ages of 20 and 40 years; at least 20 years (including the 20th birthday) when signing the informed consent and no more than 40 years (up to the day before the 41st birthday) at the time of randomisation. * Eligible for ovarian stimulation with a dose equivalent to 150 IU GONAL-F or 225 IU GONAL-F, as judged by the investigator. * Body mass index (BMI) between 17.5 and 32.0 kg/m2 (both inclusive) at screening. * Infertile women diagnosed with tubal infertility, unexplained infertility, endometriosis stage I/II or with partners diagnosed with male factor infertility, eligible for in vitro fertilisation (IVF) or intracytoplasmic sperm injection (ICSI) using fresh or frozen ejaculated sperm from male partner or sperm donor * Infertility for at least one year before randomisation for subjects \<35 years or for at least 6 months for subjects ≥35 years (criteria not applicable in case of tubal or severe male factor infertility). * Regular menstrual cycles of 24-35 days (both inclusive), presumed to be ovulatory. * Transvaginal ultrasound documenting presence and adequate visualisation of both ovaries, without evidence of significant abnormality. Both ovaries must be accessible for oocyte retrieval. * Early follicular phase (cycle day 2-4) serum levels of follicle-stimulating hormone (FSH) between 1 and 15 IU/L (results obtained within 3 months prior to randomisation). * Serum anti-Müllerian hormone (AMH) concentration of ≤35 pmol/L at screening. Exclusion Criteria: * Primary ovarian failure. * More than three previous controlled ovarian stimulation cycles initiated, regardless of outcome. * History of previous episode of OHSS, exuberant ovarian response to gonadotropins, or polycystic ovarian syndrome. * Known endocrine or metabolic abnormalities (pituitary, adrenal, pancreas, liver or kidney) which can compromise participation in the trial with the exception of controlled thyroid function disease. * Known tumours of the ovary, breast, uterus, adrenal gland, pituitary or hypothalamus which would contraindicate the use of gonadotropins. * Fibroid tumours of the uterus incompatible with pregnancy. * Currently breast-feeding. * Known inherited or acquired thrombophilia disease. * Active arterial or venous thromboembolism or severe thrombophlebitis, or a history of these events. * Known porphyria.