Study On Correlation Of Sperm DNA Fragmentation On The Blastocyst After Transplantation Of Freezing And Thawing

ObjectiveIn Assisted Reproductive Technology（ART），sperm DNA damage isone of the most important factors that affect the clinical outcome, andmore and more attention has been paid to it. So it is necessary to detectsperm DNA fragmentation index （DFI）and obtain sperm with no orsmaller DNA damage to improve clinical outcomes. Sperm with DNAdamage still have the ability to fertilize an ovum, and oocyte has theability to repair DNA damage, but once the DNA damage exceeds therepair capacity of the oocyte, embryonic debris and low embryoformation and development rate will occur. Foreign articles reported thatthere is a negative correlation between DFI and the fertilization rate andfresh planting rate. This study used SCD to detect DFI value to see itscorrelation on the blastocyst after transplantation of freezing and clinicalpregnancy rate so as to discover the influence of sperm DNA damage hadon the blastocyst after transplantation of freezing and to offerexperimental evidence to improve the safety of ART and clinicaloutcomes. Materials and MethodsWe choose556patients undergoing the Blastocyst afterTransplantation of Freezing and Thawing from April2010to June2013in our Center of Reproductive Medicine in The Hospital of ShenyangJinghua. Sperm analysis was performed according to WHO criteria.Sperm density and activity were analyzed by the computer assisted spermanalysis (CASA) and sperm morphology was evaluated according to theTygerberg’s standard. Sperm DFI were detected by SCD method withHalosperm kit （Halotech dna， Spain）,under the200timeslight-microscopy, comparing sperm nucleus and nucleus around halo size,then calculating sperm DNA fragment index.Conventional controlled ovary hyperstimulation were performed on allthe women which were chose in our study.32-36hours after HCGinjection, ovum pick-up (OPU) was conducted under the guidance ofvaginal ultrasound. Oocyte retrieved were in vitro fertilized and embryotransplantation were conducted2to3days later. We continuedCultivation of embryos not transplanted for another3-4days to reachblastocyst stage and froze blastocysts. The patients of this experiment isto freeze thawing blastocyst transplant, according to the number ofblastocysts and planting counts bursa plant rate.Results1. The General Condition of ExperimentationThere were556patients in556cycles in this study. Mean age of female and male patient was31.22±3.97and33.67±5.24. The average number ofblastocyst transplant was0.71, implantation rate was33.21％, Accordingto the result of ROC analysis, the fragment rate of less than20%for lowDFI group, greater than or equal to20%divided into high DFI group.215for low DFI group, mean age of female and male patient was30.66±3.67and33.11±5.10, the average number of blastocyst transplant was0.61,implantation rate was38.29％. And341for high DFI group, mean age offemale and male patient was31.52±4.09and33.97±5.29, the averagenumber of blastocyst transplant was0.66, implantation rate was28.13％.2.The effect of sperm DNA damage on the blastocyst aftertransplantation of freezing and thawing outcomes.Patients were divided into two groups according to the DFI value, DFI＜20％for low DFI group and DFI≥20％for high DFI group. Resultsshowed that there was no statistical differences in terms of mean age offemale and male patient and the average number of blastocyst transplant, inbetween the two groups（P＞0.05）. Low DFI maybe lead to implantationrate and clinical pregnancy rate decreased significantly(P＜0.05）.3.Effect of age on DFI effect in the blastocyst after transplantation offreezing and thawing outcomes.Patients divided into two groups according to patient age, less than35years old for low age group and older than that for high age group.Low age group and high age group were divided into2groups respectively according to the DFI value, DFI＜20％for group (1) andDFI≥20％for group（2）. Results showed that in low age group the highDNA damage maybe lead to implantation rate and clinical pregnancy ratestatistically significant（P＜0.05）. In High age group, there were nostatistical differences between group (1) and（2）in implantation rate andin clinical pregnancy rate（P＞0.05）.Conclusion1. Although the development of sperm DNA damage does not affectthe embryo before planting, but can reduce the embryo implantationpotential, high sperm DNA damage caused a significant decline ofimplantation rate and clinical pregnancy rate of blastocyst aftertransplantation of freezing and thawing.2.The woman’s age is an important factor that sperm DNA damageaffects clinical outcome of conventional IVF. Oocyte repair ability isclosely related to the age of the women.. For those with advanced age,DNA damage repair ability is poor so DFI has no influence on blastocystformation, there were no statistical differences in clinical pregnancy rateand implantation rate,.3. For those with low age, DNA damage repair ability is good, Forthe low sperm DNA fragmentation can be in good repair, so there werenegative correlations in clinical pregnancy rate and implantation rate,.4. In view of the high DNA group implantation rate was significantly lower than that in low DFI group, in the transplantation process can beobtained by increasing the number of transferred embryos(transplantation two blastocysts), hopes to increase implantation rate ofhigh DNA group.