Impact of sperm DNA fragmentation on clinical IVF outcomes

Abstract

Background and Objective: Ongoing debates exist regarding the impact of sperm DNA fragmentation (SDF) on clinical IVF outcomes. The aim of this study is to investigate whether SDF levels affect fertilization rate, pregnancy rate and miscarriage rate in couples undergoing fresh IVF cycles. Method: This retrospective study investigated 169 consecutive fresh IVF cycles performed between January 2012 and June 2014. Semen was collected on the day of oocyte retrieval and standard sperm quality was assessed in the raw semen. In addition to standard semen parameters, SDF was also measured by TUNEL method. Poor ovarian responder (POR) was defined when three or less mature oocytes were collected. Oocytes were inseminated by the conventional method (n = 69) or by ICSI (n = 95) depending on the quality of sperm and oocyte. The embryos were transferred three or five days after oocyte retrieval. Miscarriage was defined as pregnancy loss before 12 weeks of gestation. Results: SDF level did not affect fertilization rate or pregnancy rate, but SDF level did have a significant effect on miscarriage rate. In the miscarriage group (n = 10), SDF level was significantly higher (23.9% vs. 14.1%) and number of mature oocytes was significantly lower (4.3 vs. 7.6) when compared with the live birth group (n = 45). Multiple regression analysis showed that SDF level was an independent predictor for miscarriage (OR 1.051, 95% CI 1.001 - 1.104). For prediction of miscarriage, the cutoff for SDF level was >13% and the cut-off for number of mature oocytes was ≤3. In the low SDF group (≤13%), miscarriage rate was similar between POR and normal ovarian responder (NOR) (14.2% vs. 4.3%). In the high SDF group (>13%), miscarriage rate was significantly higher in POR than NOR (60% vs. 13.3%, p = 0.045). Conclusion: This study demonstrated that high SDF level (>13%) was associated with high miscarriage rate. High SDF level contributes to miscarriage only in the POR group. The results suggest that SDF measurement should be considered in couples with POR in order to predict the prognosis of the IVF pregnancy