This study proposes to evaluate the effect of adding HP-hMG (Menopur) to follitropin delta in a "mixed protocol" regimen, using an individualized, fixed dose of follitropin delta based on the established algorithm, combined with a variable, adjustable dose of Menopur based on body weight and ovarian reserve.

The initial dose of follitropin delta will be determined at enrolment by the analysis of serum AMH on days 2 to 5 of the menstrual cycle preceding the IVF treatment cycle and body weight in Kg The initial dose of HP-hMG to be added on top of follitropin delta will be determined at enrolment by the total follitropin delta dose and body weight in Kg

Inclusion Criteria:

• Women 18 to 40 years of age undergoing their first IVF/ICSI cycle
• Diagnosed with unexplained infertility, tubal infertility, endometriosis stage I/II, or with partners diagnosed with male factor infertility
• Regular menstrual cycles of 24-35 days
• Presence of both ovaries
• Early follicular phase FSH serum concentration <10 IU/L measured between Day 2 to Day 5 of menstrual cycle within the previous 12 months
• Ejaculated sperm (fresh or frozen) for insemination

Exclusion Criteria:

• Inability to consent
• Endometriosis stage III and IV
• High risk of OHSS (AMH ≥ 35 pmol/L)
• History of recurrent miscarriages defined as ≥ 3 consecutive losses
• Women undergoing egg donation
• Women participating in any other research project
• Use of hormonal preparations (except for thyroid medication) during the last menstrual cycle
• Hypersensitivity to follitropin delta and/or HP-hMG