Comparison Of Pregnancy And Perinatal Outcomes Between Cleavage-Stage Transfer And Blastocyst Transfer

Objective:To compare the pregnancy and perinatal outcomes of cleavage-stage and blastocyst transfer,and to explore the best strategy of embryo transfer in different infertile patients.Methods:1.Research object:In this retrospective cohort study,data of patients who underwent IVF/ICSI from 2021 to 2022 in Reproductive Medicine Department of Fifth Hospital and First Hospital of Shanxi Medical University and Jinzhong yingtai women’s and children’s hospital.2.Research method:According to the criteria,patients were divided into cleavage-stage transfer group(D3group,n=2827)and blastocyst transfer group(D5 group,n=1253).There were 2065 live births and 1591 single births.Due to the potential impact of transfer cycles on perinatal outcomes,subgroup analysis was performed.Divided frozen-thawed embryo transfer into IV cleavage-stage transfer group(D3Ⅰ group,n=409)and blastocyst transfer group(D5Ⅰgroup,n=290).Divided fresh embryo transfer into D3Ⅱ group(n=662)and D5Ⅱ group(n=230).The main outcome measures were large for gestational age(LGA)and preterm birth(PTB).The second outcome measures were clinical pregnancy rate,live birth rate,implantation rate,ectopic pregnancy rate,monozygotic twin rate,multiple pregnancy rate,abortion rate,early abortion rate,late abortion rate,gestational age,neonatal sex and birth weight.Univariate and multivariate logistic regression were applied to analyze the correlation between D3 group and D5 group and adverse outcome.Results:1.The clinical pregnancy rate(AOR 1.76,95%CI 1.52-2.04),live birth rate(AOR 1.53,95%CI 1.33-1.77),implantation rate(AOR 1.72,95%CI 1.49-1.99),multiple pregnancy rate(AOR 1.27,95%CI 1.03-1.58)and male newborns(AOR 1.37,95%CI 1.13-1.67)in group D5 were significantly higher than those in group D3(P<0.05).2.Perinatal outcomes of singleton pregnancy in D5 group and D3 group: PTB(AOR1.35,95%CI 1.04-1.77)and LGA(AOR 2.80,95%CI 2.03-3.85)in D5 group were significantly higher than those in D3 group(P<0.05).There was no significant difference in macrosomia,Very preterm birth(VPTB),Very low birthweight(VLBW),Low birthweight(LBW),Small for gestational age(SGA)between the two groups(P>0.05).3.The perinatal outcomes of twin pregnancy in D5 group and D3 group: there was no significant difference in VPTB,PTB,VLBW,LBW,macrosomia,SGA and LGA between the two groups(P>0.05).4.In D5 group,the risk of LGA in male infants(AOR 2.95,95 % CI 2.01-4.33)and female infants(AOR 2.04,95 % CI 1.10-3.77)was significantly higher than that D3group(P > 0.05).5.In subgroup FET,LGA(AOR 3.57,95%CI 2.30-5.54)and macrosomia(AOR 1.90,95%CI 1.08-3.35)in D5Ⅰ group were significantly higher than those in D3Ⅰ group(P<0.05).There was no significant difference in VPTB,PTB,VLBW,LBW and SGA between the two groups(P>0.05).6.In subgroup fresh embryo transfer,LGA(AOR 2.18,95%CI 1.33-3.58)in D5Ⅱ group was significantly higher than that in D3Ⅱ group(P<0.05).There was no significant difference in VPTB,PTB,VLBW,LBW macrosomia and SGA between the two groups(P>0.05).Conclusion:1.Pregnancy outcomes: the clinical pregnancy rate,implantation rate,live birth rate,multiple pregnancy rate and male neonatal rate of group D5 were significantly higher than those of group D3.2.Perinatal outcomes: the incidence of LGA and PTB in group D5 was higher than that in group D3.Decreasing the possible impact of the transfer cycle on perinatal outcomes,the incidence of LGA in the D5 group was also significantly increased.At the same time,we considered that frozen-thawed embryo transfer was also a risk factor for LGA.3.In view of the increased risk of LGA after D5,we should choose the appropriate embryo transfer method according to the patient.