Application Of Low-Molecular-Weight Heparin Sodium In Frozen-Thawed Embryo Transfer Cycle Of Patients With Repeated Implant Failure

Background: Repeated implantation failure(RIF)is one of the hottest and most difficult issues in the field of reproductive medicine.The pathogeny of RIF include embryonic factors,endometrial factors,maternal prethrombotic state,maternal and fetal interface immune disorders etc.Some studies have shown that low molecular weight heparin can improve endometrial receptivity,improve maternal prethrombotic state,regulate immunity and so on,so it is considered to improve the assisted reproductive assisted pregnancy outcome and pregnancy outcome in patients with repeated implant failure,but its clinical effect has not been fully confirmed.Thus,we conducted this study..Objective: To study the effect of low molecular weight heparin sodium on assisted reproductive outcome of frozen-thawed cycle in patients with repeated implantation failure.Materials and methods:A retrospective analysis was made on the frozen-thawed cycles performed on patients diagnosed as recurrent implantation failure during assisted reproductive treatment in our hospital from June,2017 to May,2019.According to whether the clinician uses the preventive dose of low molecular weight heparin sodium after embryo transfer during the thawing transfer cycle with the conventional luteal support,the patients were divided into the heparin group(104 cycles)and the non-heparin group(77 cycles).General data and medical records of patients were collected to compare the differences between heparin group and non-heparin group in clinical data and assisted reproductive outcomes(including clinical pregnancy rate,embryo implantation rate,live birth rate,premature birth rate,abortion rate,average weight of newborn,etc.).Results: There was no significant difference in the distribution of general data between heparin group and non-heparin group.The clinical pregnancy rate(56.73%vs40.26 %,P<0.05)and embryo implantation rate(40.00%vs27.46%,P<0.05)of heparin group were significantly higher than that of non-heparin group,compared with non-heparin group,the live delivery rate of heparin group was significantly higher(43.27%vs28.57%,P<0.05).Compared with non-heparin group,premature delivery rate of heparin group was lower(1.69%vs9.68%,P>0.05),early abortion rate(15.25%vs19.35%,P>0.05)and late abortion rate(8.47%vs9.68%,P>0.05)was lower,while there was no statistical significance,the average weight of newborns in heparin group was higher than that in non-heparin group(3205.21±475.94vs3105.21±488.71,P>0.05),but there was no statistical difference.Conclusion :Low molecular heparin sodium can improve embryo implantation rate and clinical pregnancy rate when patients with repeated implantation failure undergo frozenthawed transplantation again.but does not significantly improve pregnancy outcome?...