PGD周期中机械法和激光法活检对胚胎发育及妊娠结局的影响

目的:比较机械法和激光法进行卵裂球和极体活检对胚胎发育及着床前遗传学诊断(preimplantation genetic diagnosis,PGD)周期妊娠结局的影响。方法:本研究包括20对夫妇的21个PGD周期,其中18个周期分别用机械法或激光法于受精后第3天进行卵裂球活检,并用荧光原位杂交(fluorescence in situ hybridization,FISH)分析检出的卵裂球,于受精后第5或第6天移植信号正常的胚胎;2个周期分别用机械法和激光法在取卵后行极体活检,后行胞浆内单精子注射(introcytoplasmic sperm injection,ICSI)。同时将活检取出的极体进行FISH分析,于取卵后第3天移植经FISH检查正常的卵发育而来的胚胎。另外一个周期先用激光法实行了极体活检,由于FISH检查均无信号,后又用激光法对胚胎行卵裂球活检。结果:共活检胚胎145枚,其中109枚用机械法,36枚用激光法。活检后胚胎的继续发育率分别为72.48%和83.33%,囊胚形成率为33.94%和44.44%,临床妊娠率为38.46%和16.67%,着床率为21.43%和8.33%,两种方法无显著差异。对27枚卵行极体活检,其中12枚用机械法,15枚用激光法。活检后2PN受精率分别为58.33%和46.66%,继续发育率为66.67%和60.00%,亦无显著差异。对活检出的极体进行FISH分析,用机械法活检的极体信号阳性率为90.00%,显著高于激光法的28.57%。结论:用机械法和激光法行极体或卵裂球活检对胚胎发育的影响差异无统计学意义。但使用机械法活检卵裂球能获得较高的临床妊娠率和着床率。极体活检时能获得较高的受精率和继续发育率,故推荐使用机械法进行活检。

Comparison of the influence of mechanical and laser methods for biopsy of blastomeres or polar bodies on the development of embryo and pregnancy in PGD cycles

Objective:To compare the results of the PGD by mechanical and laser methods in order to find an optimal and safe method for embryo or occyte biopsy.Methods:Twenty-one PGD-IVF cycles for 20 couples were included overall,during one and a half years period.The embryo biopsy was carried out by mechanical method or laser at 6~8-cell stage on day 3.One or two blastomeres were removed from each embryo.The nuclei of all blastomeres were analyzed by FISH procedure.Normal embryos were transferred on day 5 or day 6.Oocytes were biopsied and the first polar bodies were fixed within 6 hours after oocyte retrieval.After that,oocytes were inseminated by ICSI,while the polar bodies were analyzed by FISH.The normal embryos were transplanted 6 days after oocytes collection.Results:A total of 145 embryos underwent blastomere biopsy.There was no significant difference in clinic pregnancy rate(38.46% vs 16.67%),implantation rate(21.43% vs 8.33%) and blastocyst rate on D5/D6(33.94% vs 44.44%) between the two groups biopsied by mechanical method and laser.In total,27 oocytes were analysed.There was no significant difference in 2pn insemination rate(58.33% vs 46.66%),after growth rate(66.67% vs 60.00%) post biopsy,successful fixing rate(83.33% vs 28.75),whereas FISH signal positive rate(90.00% vs 28.75%) was significant different between the two groups.Conclusion:Both mechanical method and laser for zona drilling in cases of PGD can get similar clinical pregnancy rate and implantation rate.In spite of that,it is better in all parameters with mechanical biopsy.It is advantageous to use mechanical method for zona drilling.