Impact of sperm DNA fragmentation on clinical in vitro fertilization outcomes

Objective We studied the association between sperm DNA fragmentation (SDF) and several clinical in vitro fertilization outcomes. Methods We retrospectively analyzed 169 consecutive fresh IVF cycles. Semen was collected on the day of oocyte retrieval, and we assessed standard semen parameters and the SDF level (by terminal deoxynucleotidyl transferase dUTP nick-end labeling). Poor ovarian response (POR) was defined as the collection of three or fewer mature oocytes. Oocytes were inseminated by the conventional method or intracytoplasmic sperm injection. Results SDF did not affect the fertilization or pregnancy rate, but did have a significant effect on the miscarriage rate. In the miscarriage group (n=10), the SDF level was significantly higher (23.9% vs. 14.1%) and number of mature oocytes was significantly lower (4.3 vs. 7.6) than in the live birth group (n=45). Multiple regression analysis showed that SDF was an independent predictor of miscarriage (odds ratio, 1.051; 95% confidence interval, 1.001-1.104). The cutoffs for the SDF level and number of mature oocytes that could predict miscarriage were >13% and ≤3, respectively. In the low-SDF group (≤13%), the miscarriage rate was similar in POR patients and those with a normal ovarian response (NOR; 14.2% vs. 4.3%). In the high-SDF group (>13%), the miscarriage rate was significantly higher in the POR group than in the NOR group (60.0% vs. 13.3%, p=0.045). Conclusion Our study demonstrated that a high SDF level (>13%) was associated with a high miscarriage rate, and that it mainly contributed to miscarriage in the POR group. The results suggest that SDF measurements should be considered in couples with POR in order to predict the prognosis of the pregnancy.