OBJECTIVE: Correlations between semen parameters and sperm DNA fragmentation index (DFI) were investigated to identify characteristics of sperm without DNA damage that could be used in selecting sperm for intracytoplasmic sperm injection (ICSI). Pregnancy outcomes were compared to determine whether in vitro fertilization (IVF) or ICSI is a better choice for patients who have sperm with a high-DFI. METHODS: Semen analysis was carried out in 388 patients who visited our IVF center for the first time to investigate correlations between sperm DFI and semen parameters. In addition, 1,102 IVF cycles in 867 patients were carried out in the present study; 921 cycles in the low-DFI group (DFI <30%) and 181 cycles in the high-DFI group (DFI ≥30%). Both the low- and high-DFI groups were subdivided into IVF and ICSI cycle groups. RESULTS: Sperm DFI showed significant inverse correlations with sperm motility (r=−0.435, p<0.001) and morphology (r=−0.153, p<0.05). Sperm DFI also showed significant correlations with rapid motility (r=−0.436, p<0.001), and the kinetic parameters of average-path velocity (r=−0.403) and linearity (r=−0.412). Although there was no significant difference in the pregnancy rates between IVF (48.6%) and ICSI (44.8%) in the low-DFI group, the pregnancy rate of ICSI cycles (44.8%, p<0.05) was significantly higher than IVF cycles (25.0%) in the high-DFI group. No significant difference was observed in the abortion rates between the low-DFI (52 of 921, 5.6%) and high-DFI groups (7 of 181, 3.8%). CONCLUSION: ICSI is a better choice than IVF for improving the pregnancy outcomes of patients who have sperm with a high DFI.
Abortion, Induced ; DNA Damage ; DNA Fragmentation* ; DNA* ; Female ; Fertilization in Vitro ; Humans ; Pregnancy Outcome ; Pregnancy Rate* ; Pregnancy* ; Semen ; Semen Analysis ; Sperm Injections, Intracytoplasmic* ; Sperm Motility ; Spermatozoa*

OBJECTIVE: To determine whether fragment removal on in vitro fertilization (IVF) day 2 improved the subsequent development and pregnancy outcomes of fragmented embryos compared to similar-grade embryos without fragment removal. METHODS: This study was a retrospective analysis involving 191 IVF cycles in which all embryos had over 10% fragmentation (grade 3 or 4) on day 2 of the IVF-embryo transfer cycle from March 2015 to December 2017. IVF cycles were divided into the fragment removal group (n=87) and the no fragment removal group (n=104) as a control cohort. Before fragment removal, embryos with fragmentation on day 2 were incubated in Ca2+- and Mg2+-free biopsy medium under paraffin oil for 30 minutes. Microsurgical fragment removal was performed with later-assisted hatching and a handmade suction micropipette that had an outer diameter of 30 µm. RESULTS: There were no significant differences in the characteristics of the patients between the control and the fragment removal groups. After fragment removal and subsequent in vitro culture for 24 hours, the number of blastomeres (7.1±1.7 vs. 6.9±1.6) was comparable between the transferred embryos in the two groups, but the morphological grade of the embryos in the fragment removal group (1.9±0.7) was significantly higher than that of the control group (3.1±0.5, p < 0.01). The clinical pregnancy (43.7%) and implantation rates (25.8%) in the fragment removal group were significantly higher than those in the control group (28.8% and 14.0%, respectively; p < 0.05). CONCLUSION: Early fragment removal on day 2 significantly improved the subsequent development and pregnancy outcomes of fragmented embryos.
Biopsy ; Blastomeres ; Cohort Studies ; Embryonic Structures* ; Female ; Fertilization in Vitro* ; Humans* ; In Vitro Techniques* ; Paraffin ; Pregnancy ; Pregnancy Outcome ; Retrospective Studies ; Suction