胚胎培养液中线粒体DNA拷贝数与胚胎质量关系的研究

Study on the relationship between embryo quality and mitochondrial DNA copies in embryo culture medium

目的研究第3天(day 3,D3)卵裂期胚胎质量与胚胎培养液中线粒体DNA(mitochondrial DNA,mtDNA)拷贝数的关系。方法选择2017年7月至2018年10月于成都中医药大学医学与生命科学学院/附属生殖妇幼医院生殖医学中心行辅助生殖技术助孕的67个新鲜卵裂期胚胎移植周期的共93个胚胎,应用数字聚合酶链式反应(polymerase chain reaction,PCR)方法检测胚胎培养液中mtDNA拷贝数。根据形态学总体评价分为优质胚胎组(n=54)和非优质胚胎组(n=39),根据胚胎发育速度分为正常速度组(n=67)和异常速度组(n=26),根据胚胎评分分为高分组(n=72)和低分组(n=21),比较各组胚胎培养液中mtDNA拷贝数,女方年龄、体重指数(body mass index,BMI)、基础内分泌条件及妊娠结局等的差异。采用独立样本t检验和秩和检验进行统计学分析。结果在其他条件相似的情况下,胚胎培养液中形态学总体评价优质胚胎组平均mtDNA拷贝数[(1.30±1.99)copy/μl]明显高于非优质胚胎组[(0.91±0.94)copy/μl],差异有统计学意义(P<0.05)。胚胎发育正常速度组平均mtDNA拷贝数[(1.28±1.86)copy/μl]明显高于异常速度组[(0.78±0.71)copy/μl],差异有统计学意义(P<0.05)。胚胎评分高分组mtDNA拷贝数[(1.13±1.76)copy/μl]和低分组[(1.15±1.15)copy/μl]比较差异无统计学意义(P>0.05)。结论通过数字PCR技术检测胚胎培养液中mtDNA拷贝数的方法可以作为评价胚胎质量的一种新型非侵入性手段,联合形态学评分与数字PCR方法检测胚胎培养液中mtDNA拷贝数共同评价胚胎质量的准确性可能更高。胚胎质量越好,其培养液中mtDNA拷贝数越高。

Objective To investigate the relationship between Day 3 embryo quality and mitochondria DNA(mtDNA)copies in embryo culture medium.Methods From July 2017 to October 2018,93 culture media of transferred embryos from 67 patients who accepeted assisted reproductive technology in School of Medical and Life Sciences/Reproductive&Women-Children Hospital,Chengdu University of Traditional Chinese Medicine were selected to assessed mitochondria DNA copies by digital polymerase chain reaction(PCR)technology.According to the cleavage embryo grading criteria,embryos were divided into good quality group(n=54)and poor quality group(n=39),normal development rate group(n=67)and abnormal development rate group(n=26),high score group(n=72)and low score group(n=21),respectively.The differences of mtDNA copies,female age,body mass index(BMI),basic endocrine condition and clinical outcome were analysed by t-test or ranks test.Results All the other conditions were nonsignificant except mitochondria DNA copies between groups.The mitochondria DNA copies in embryo culture media of good quality group was significant higher than poor quality group[(1.30±1.99)vs(0.91±0.94),P<0.05],normal development rate group was significant higher than abnormal development rate group[(1.28±1.86)vs(0.78±0.71),P<0.05].But there was no significant difference between both the high score group and the low score group of the mitochondria DNA copies in embryo culture media[(1.13±1.76)vs(1.15±1.15)copy/μl,P>0.05].Conclusions Assessing mitochondria DNA copies by digital PCR technology in the Day 3 embryo culture medium,in combination with morphological grading,may be a novel,non-invasive,sensitive method to evaluate embryo quality.Good quality and normal development rate embryo could secrete higher mitochondria DNA copies into embryo culture media.