Decreased fertilization rate and embryo quality after ICSI in oligozoospermic men with microdeletions in the azoospermia factor c region of the Y chromosome.

Microdeletions of the azoospermia factor (AZF) region of the Y chromosome occur in between 1 and 29% of oligozoospermic and azoospermic men, and most deletions are found in the AZFc region. These men can father children when intracytoplasmic sperm injection (ICSI) is used, but the success rate is unclear. Thus, the success rate of 19 ICSI treatments in eight couples with a microdeletion in the AZFc region of the Y chromosome was analysed retrospectively. These were compared with a control group of 239 ICSI treatments in 107 couples undergoing ICSI treatment with ejaculated spermatozoa. The fertilization rate was significantly lower in the group of Y-deleted men (55%; 95% CI: 41-69%) compared with controls (71%; 95% CI: 67-74%; P < 0.01). The embryo quality was also significantly poorer among Y-deleted men (P<0.001). Pregnancy, implantation and take-home baby rates were not significantly lower in the Y-deleted group. This study shows that ICSI in oligozoospermic men with microdeletions in the AZFc region of the Y chromosome leads to a lower fertilization rate and poorer embryo quality.