IVF-ET周期中胚胎污染的实验室与临床结局分析

Analysis on In Vitro Culture and Clinical Outcomes of Embryo Contamination During IVF-ET Cycles

【目的】探讨体外受精-胚胎移植(IVF-ET)周期中体外培养的胚胎发生污染的情况及其实验室培养和临床结局。【方法】回顾性分析2010年1月至2020年12月中山大学孙逸仙纪念医院生殖中心IVF-ET周期中70例胚胎污染的相关资料,比较不同授精方式的污染发生率、体外培养第1~3天(D1-D3)的污染发现率、以及卵泡液、精液、培养液3种标本的污染发生率,统计污染的微生物类型,比较全污染组(42例)和部分污染组(28例)的实验室培养及临床结局相关参数。【结果】在29583个周期中共出现70例胚胎污染(0.24%),所有污染均为体外受精(IVF)来源的胚胎而非卵胞浆内单精子注射(ICSI)来源的胚胎;在体外培养不同天数中,D2污染发现率最高(54.3%),其次是D1(32.9%)和D3(12.9%);与卵泡液相比,精液是导致D1-D3污染发现的主要原因;卵泡液的主要污染源是粪肠球菌(18.0%),精液和培养液的主要污染源是大肠杆菌(59.6%,66.7%),同时有5例污染周期的培养液中出现与卵泡液、精液均不一致的细菌类型;与全污染组相比,部分污染组的无可用胚胎周期率显著性降低(6/28 vs.34/42,21.4%vs.81.0%,P<0.001),囊胚形成周期率有升高趋势(5/12 vs.2/7,41.2%vs.28.6%,P=0.656),同时,部分污染组新鲜周期与解冻周期移植后的临床妊娠例数、活产例数均高于全污染组。【结论】ICSI受精方式可有效避免胚胎污染发生;胚胎污染主要在体外培养的第2天发现,污染主要来源是精液携带的大肠杆菌;当只有部分胚胎发生污染时,仍可获得较好的实验室和临床结局。

【Objective】To explore the occurrence,in vitro culture effect and clinical outcomes of embryo contamination during in vitro fertilization and embryo transfer(IVF-ET)cycles.【Methods】A retrospective analysis was made on the embryo contamination cases during IVF-ET treatment at Reproductive Medicine Centre,Department of Obstetrics and Gynecology,Sun Yat-sen Memorial Hospital,Sun Yat-sen University from January 2010 to December 2020.We compared the contamination of 4 different insemination methods,contamination on 3 different in vitro culture days(D1,D2,D3)and contamination of 3 different samples(follicular fluid,semen and culture medium).The source of contamination and types of microbes were identified.We also compared in vitro culture and clinical outcomes between two groups(42 cases of all embryos contaminated and 28 cases of partial embryos contaminated).【Results】Among the 29583 cycles examined,70 cycles had microbial contamination(0.24%),and all contaminated embryos were from in vitro fertilization(IVF)source rather than intracytoplasmic sperm injection(ICSI)source.The contamination rate on D2 was the highest(54.3%),followed by those on D1(32.9%)and D3(12.9%).Compared with follicular fluid,semen is the most common source of contamination from D1-D3.The most common contaminants identified was Enterococcus faecalis in follicular fluid(18.0%),while it was Escherichia coli in semen(59.6%)and culture medium(66.7%).Moreover,the types of bacteria in culture medium were not consistent with those in follicular fluid and semen in 5 cases of microbial contamination.Compared with the Total contaminated group,the Partial contaminated group showed a significant decrease in No available embryo rates(6/28 vs.34/42,21.4%vs.81.0%,P<0.001)and a rising trend in formation of blastocyst rates(5/12 vs.2/7,41.2%vs.28.6%,P=0.656),meanwhile,the clinical pregnancy cases and live births cases after transplantation of fresh and frozen-thawed cycles in Partial contaminated group were higher than those in the Total contaminated group.【Conclusion】ICSI can effectively reduce embryo contamination.Embryo contamination mainly occurred on D2 in vitro culture and the most common contamination source is Escherichia coli in semen.Partial embryo contamination may still result in good in vitro culture effect and clinical outcomes during IVF-ET cycles.