摘要Objective:To explore the roles of advanced paternal age(APA)and abnormal paternal weight on embryo quality and pregnancy outcomes for unexplained recurrent pregnancy loss(uRPL)couples who underwent preimplan-tation genetic testing for aneuploidies(PGT-A).Methods:This study included 779 uRPL couples who underwent their first PGT-A cycles between 2014 and 2018.Male patients'aging and nutritional status were quantified by paternal age and body mass index(BMI).Routine semen parameters and sperm DNA fragmentation index(DFI)were used to reflect the seminal quality.Blastocyst formation rate and aneuploidy rate were used to reflect the embryo quality.Cycle cancellation rate,implantation rate,pregnancy loss rate,and live birth rate were measured to evaluate the treatment efficiency from IVF.To remove the interference of maternal age,only the women younger than 38 years old were included.After uni-variate screening,interaction tests were performed in a generalized linear model(GLM)to further examine the effects of paternal age and BMI on each outcome indicator.Results:In the total population(779 cycles),there were no statistical differences in aneuploidy rate,cycle cancellation rate,implantation rate,pregnancy loss rate,and live birth rate,whether stratified by paternal age or paternal BMI.Similar results occurred in the younger men(＜40 y.o.,633 cycles).Conversely,among the men with advanced age(＞40 y.o.,146 cycles),there were statistical differences between the three BMI groups in four semen parameters(total sperm number,total motility,progressive motility,and total motile sperm count),im-plantation rate,and live birth rate.After interaction testing,the results of GLM suggested that the interaction effect between APA and paternal obesity was associated with the low implantation rate of uRPL couples.Conclusions:For the uRPL couples seeking for PGT-A treatment,if the male patients have both advanced age and obesity,their spouses are at higher risks for embryo implantation failure.