The effect of azoospermia factor microdeletions on intracytoplasmic sperm injection results in azoospermia patients

Y chromosome abnormalities are common in male patients with severe oligo-azoospermia. In studies with karyotype analysis and cytogenetic methods, the importance of the Y chromosome in spermatogenesis has been well understood. Deletions in the azoospermia factor (AZF) localized at the distal end of the Y chromosome adversely affect the spermatogenesis process. Our objective was to determine the frequency of AZF microdeletion in azoospermia patients who underwent microTESE.

In this retrospective cohort study, 806 azoospermic men attending the In Vitro Fertilization (IVF) Center for infertility treatment between 2010 and 2022 were included. AZF deletion screening was conducted in all patients included in the study. Azoospermic patients with and without Y microdeletion were matched with the female's age, cause of infertility, number of oocytes retrieved and number of metaphase II (MII) oocytes produced and compared. The primary outcome was the live birth rate (LBR). Pregnancy rate (PR) and clinical pregnancy rates (CPR) were secondary outcomes.

We detected Y microdeletion in 55 (6.82%) of 806 infertile azoospermic men and 35 of them included in the study. Although the required gonadotropin dose and the total number of retrieved oocytes were similar, clinical pregnancy rates and live birth rates were found to be significantly lower in the microdeletion patient group (21.6% vs. 43%, p<0.05; and 18.9% vs. 36%, p<0.05, respectively).

Poor sperm quality in AZF microdeletion patients complicates the selection of appropriate sperm for ICSI. Therefore, it leads to a decrease in embryonic development, fertilization and pregnancy results. In order to select the best sperm for the use in ICSI procedure in this patient population, intracytoplasmic morphologically selected sperm injection (IMSI) method can be preferred to improve the cycle outcomes.