Sperm DNA fragmentation and male age: results of in vitro fertilization treatments

OBJECTIVE: This study aimed to assess the effects of sperm DNA fragmentation in parents belonging to different age groups. The couples included in the study comprised normozoospermic men and infertile women undergoing conventional IVF. METHODS: The results obtained from 163 conventional IVF cycles were analyzed retrospectively. The couples enrolled in the study included women aged between 30 and 37 years. Sperm DNA fragmentation was studied using the TUNEL assay. The patients were split into four groups based on male age and sperm DNA fragmentation, as follows: Group 1: ≤39 years and TUNEL assay ≤20%; Group 2: ≤39 years and TUNEL assay >20%; Group 3: ≥40 years and TUNEL assay ≤20%; and Group 4: ≥40 years and TUNEL assay >20%. RESULTS: No significant differences were found in semen parameters or fertilization rates between groups. Groups with <20% sperm DNA fragmentation showed significant differences in other parameters, including higher blastocyst formation rate (Group 1: 63% and Group 3: 60% vs. Group 2: 43% and Group 4: 41%, p<0.05) and higher expanded blastocyst formation rate (Group 1: 42% and Group 3: 40% vs. Group 2: 21% and Group 4: 18%, p<0.05). Miscarriage rate was significantly higher in Group 4 (42% and 46% vs. 5%, 25% and 5% in Groups 1, 2 and 3, respectively, p<0.05). CONCLUSIONS: Our results showed lower blastocyst formation rates from IVF when males had high levels of sperm DNA fragmentation. Higher miscarriage rates were also observed in couples with males aged 40+ years. These results reinforce the need to inform couples with male partners aged 40+ years about the potential risks inherent to fertility treatment.