囊胚评估参数对冻融周期临床结局及移植选择的影响

Effects of blastocyst evaluation parameters on clinical outcome and embryo selection in frozen-thawed cycle

目的探讨囊胚的形态学评估参数与冻融周期临床结局的关系。方法回顾性分析2018年1月至2020年2月在本院生殖医学科行D5或D6单囊胚冻融胚胎移植的患者临床资料共790个周期。根据移植囊胚冷冻前的发育天数、囊胚扩张程度、滋养层细胞评分和内细胞团评分分成不同亚组,分别比较各亚组之间一般资料及妊娠结局等,采用多因素logistic回归分析临床妊娠结局的影响因素,通过分类决策树建立最优多变量选择移植单囊胚顺序。结果(1)按发育天数分析,D5组患者年龄比D6组显著下降,而临床妊娠率(52.8%vs.42.1%)显著升高(P<0.05);按囊胚扩张程度分析,各组之间一般资料及临床结局均无显著性差异(P>0.05);按内细胞团评分分析,随着3组评分的减低,临床妊娠率逐渐显著下降(64.7%vs.52.3%vs.32.2%)(P<0.05);按滋养层细胞评分分析,随着3组评分的下降,临床妊娠率也逐渐显著下降(62.9%vs.52.0%vs.43.0%)(P<0.05)。(2)多因素logistic分析显示,单囊胚解冻后内细胞团评分低[OR=0.527,95%CI(1.213,2.475)]和高龄[OR=0.945,95%CI(0.913,0.979)]是临床妊娠率低的危险因素(P<0.05)。(3)分类决策树模型分析结果显示,决策树包含3层,共6个节点,第一层为内细胞团评分(χ^2=13.7,P=0.001),第二层为囊胚扩张程度(χ^2=11.1,P=0.006),第三层为滋养层细胞评分(χ^2=6.367,P=0.035);交叉验证正确百分比57.8%。结论在冻融单囊胚移植周期中,内细胞团评分低是临床妊娠率低的危险因素;选择冻融胚胎移植时,建议优先根据内细胞团级别选A或B级的囊胚,再根据扩张程度优先选5或4期的囊胚,最后根据滋养层细胞级别优先选A或B级的囊胚,以获得较高临床妊娠率。

Objective:To explore the relationship between the evaluating parameters of blastocysts and the clinical outcome of frozen-thawed cycle.Methods:The data of 790 cycles of the patients who were transferred Day 5 or Day 6 single blastocyst frozen-thawed embryos in the Department of Reproductive Medicine,the Second Hospital of Hebei Medical University from January 2018 to February 2020 were analyzed retrospectively.According to the blastocyst development days,blastocyst expansion degree,the score of trophoblast and inner cell mass before freezing,the blastocysts transferred were divided into different subgroups.The general data and pregnancy outcome were compared among the subgroups.Multivariate binary logistic regression was used to analyze the influencing factors of clinical pregnancy outcome.The optimal multivariate selection procedure for single transferred single blastocysts was established through classification decision tree.Results:(1)According to the blastocyst development days,the women’age of Day 5 group was significantly lower than that of Day 6 group,while the clinical pregnancy rate(52.8%vs.42.1%)was significantly higher(P<0.05).According to the degree of blastocyst expansion,there was no significant difference in the general condition and clinical outcome among the subgroup.According to the score of inner cell mass,the clinical pregnancy rate was significantly decreased with the decrease of the scores of the three subgroups(64.7%vs.52.3%vs.32.2%)(P<0.05).According to the score of trophoblast,the clinical pregnancy rate was significantly decreased with the decrease of the scores of the three subgroups(62.9%vs 52.0%vs 43.0%)(P<0.05).(2)Multivariate binary logistic analysis showed that the low score of inner cell mass after thawing of single blastocyst[OR=0.527,95%CI(1.213,2.475)]and the old age[OR=0.945,95%CI(0.913,0.979)]were the risk factors of low clinical pregnancy rate(P<0.05).(3)The analysis results of the classification decision tree model showed that the decision tree consists of three layers and six nodes in total.The first node was the inner cell mass score(χ^2=13.7,P=0.001);the second node was the degree of blastocyst expansion(χ^2=11.1,P=0.006);the third node was the trophoblast score(χ^2=6.367,P=0.035).The correct rate of cross validation was 57.8%.Conclusions:In the frozen-thawed single blastocyst transfer cycle,low cell mass score in blastocyst evaluation parameters is a risk factor for low clinical pregnancy rate.When selecting single blastocyst for transplantation in frozen-thawed cycle,it is suggested that blastocyst of grade A or B should be selected firstly according to the grade of inner cell mass,then the blastocysts of stage 5 or 4 were selected according to the expansion degree,and finally blastocyst of grade A or B should be selected according to the trophoblast cell score to obtain higher clinical pregnancy rate.