In assisted reproductive technology (ART) semen needs to be processed. Commonly used methods rely on physical properties of the spermatozoa, such as the swim-up methods and density gradient centrifugation. It is now known that current processing of spermatozoa does not prevent the admixture of spermatozoa with damaged genetic material. The latter have a negative impact on the outcome of ART. The investigators developed a new method for the processing of spermatozoa with intact genetic material based on flow cytometry and sorting (FACS) and on staining using a deye, YoPro. The investigators aim at examining the effect of this novel method of sperm sorting on the outcome of ART.

Inclusion Criteria:

• infertile couples needing treatment with ICSI
• male infertility as defined by the WHO 2010 criteria
• age of the treated women should be between 22 and 39 years of age.
• normal ovarian reserve, as defined by basal FSH-concentration below 10 IU/l and AMH-concentration above 10 pmol/l.
• signed consent form.

Exclusion Criteria:

• normal male infertility, as defined by the WHO 2010 criteria
• age of the treated women below 22 years and above 39 years
• reduced ovarian reserve, as defined by an elevated basal FSH-concentration or reduced AMH-concentration.
• Not more than two preceding unsuccessfull treatments with ICSI
• Severe disease of the male or female partner, such as HIV, hepatitis, or psychiatric illness.
• Participation in another study.
• lack of a signed consent form.