Received September 16, 2020
Accepted March 26, 2021

The aim of the present study was to assess the effects of sperm DNA fragmentation according to different paternal age groups in couples comprised of normozoospermic men and infertile women undergoing conventional IVF. The results obtained in 163 conventional IVF cycles were analysed retrospectively. Couples where the woman's age was between 30 and 37 years old were included. Sperm DNA fragmentation was studied using the TUNEL assay. Four groups were determined according to male age and sperm DNA fragmentation: #1: ≤39 years and TUNEL assay ≤20%; #2: ≤39 years and TUNEL assay >20%; #3: ≥40 years and TUNEL assay ≤20%; and #4: ≥40 years and TUNEL assay >20%. No significant differences were found in semen parameters or fertilization rate between groups. Groups with <20% sperm DNA fragmentation showed significant differences in other parameters, including higher blastocyst formation rate (#1: 63% and #3: 60% vs #2: 43% and #4: 41%, p<0.05) and higher expanded blastocyst formation rate (#1: 42% and #3: 40% vs #2: 21% and #4: 18%, p<0.05). Abortion rate was significantly higher in #4 (42% and 46% vs 5%, 25% and 5% in #1, #2 and #3, respectively, p<0.05). Our results showed a lower blastocyst formation rate in IVF treatments when males had a high sperm DNA fragmentation. Furthermore, if those males were older than 40 years, we found a higher abortion rate. These results show the need to inform about potential risks to couples looking for fertility treatments whose male is over 40 years of age.