卵裂期活检对胚胎体外发育能力的影响

目的　探讨不同的活检方法、活检时机和活检细胞数对胚胎体外发育能力的影响。方法　选取体外受精 胚胎移植剩余的形态学分级为Ⅰ级的胚胎 1 54个 ,对其中第 1阶段的 66个胚胎分别行化学法 (2 6个 )、机械法 (2 0个 )取出 1个卵裂球 ,并设对照 (2 0个 ) ;对第 2阶段的 88个胚胎分为用化学法取出 2个卵裂球 (44个 )和对照 (44个 )。观察记录活检时胚胎细胞数、活检时间、活检后卵裂球是否退化、活检后胚胎体外发育情况及囊胚总细胞数。结果　 (1 )化学法的活检时间为 (2 31±2 0 )s,明显短于机械法的 (2 62± 2 3)s(P <0 0 1 ) ;而囊胚形成率为 65 % ,高于机械法的 35 % (P<0 0 5)。(2 ) 6 细胞胚胎的囊胚总细胞数为 (44± 4)个 ,低于 7～ 8 细胞胚胎的 (49± 5)个和≥ 9 细胞胚胎的 (50± 6)个 (P <0 0 5) ;细胞融合的≥ 9 细胞胚胎活检后不仅囊胚形成率 (2 0 % )低于对照 (67% ,P<0 0 5) ,且活检后卵裂球退化率 (50 % )高于无细胞融合的胚胎 (1 7% ,P <0 0 5)。 (3)取出 1个或 2个卵裂球胚胎的囊胚形成率和囊胚总细胞数与对照比较 ,差异均无显著性 (P >0 0 5) ,而 6 细胞胚胎取出 2个卵裂球后囊胚形成率 (1 /8)低于对照 (5/8,P <0 0 5)。结论　化学法活检比机械法更为快速、安全 ;合适的活检时

Effects of cleavage-stage biopsy on in vitro development of human embryos

OBJECTIVE: To evaluate the effects of biopsy methods, biopsy timing and the number of cell removed on in vitro development of embryos. METHODS: One hundred and fifty four embryos of good morphology from in vitro fertilization patients were studied. Sixty-six embryos were allocated to the following three groups: chemical drilling biopsy group (26), mechanical drilling biopsy group (26) and control group (20). One cell was removed from the embryos of the two biopsy groups. The remaining 88 embryos were allocated to two groups: biopsy group (44) and control group (44). Two cells were removed from biopsy group by chemical drilling method. The stage of the embryo before biopsy, biopsy time, lysed blastomere, growth potential and hatching capacity of the biopsied embryos, total cell number at the blastocyst stage were recorded and evaluated. RESULTS: The mean time of biopsy in the chemical drilling group (231 +/- 20) seconds was significantly shorter than that in the mechanical drilling group (262 +/- 23) seconds (P < 0.01). The proportion of embryo developing to blastocyst stage was higher in chemical drilling group as compared with the mechanical group (65% versus 35%, P < 0.05). The total cell number at the blastocyst stage was fewer than those in the 7 to 8-cell embryo and >/= 9-cell embryo groups in the 6-cell embryo group (44 +/- 4 versus 49 +/- 5, 50 +/- 6; P < 0.05). At 9- to 10-cell stage, the proportion developing to the blastocyst stage was reduced in compacted embryos (20%) compared with control group (67%, P < 0.05) also more lysed blastomeres after biopsy were found in compacted embryos (50%) compared with uncompacted embryos (17%). The growth capacity to the blastocyst stage and the total cell number of the blastocyst were not different between one cell removal group and two cells removal group (P > 0.05). However, the proportion developing to the blastocyst stage was reduced after the removal of two cells from the 6-cell stage in comparison to the control (1/8 versus 5/8, P < 0.05). CONCLUSIONS: Compared with mechanical drilling biopsy, chemical drilling technique takes shorter timer and is safer. The suitable biopsy timing was >/= 7-cell stage before embryo compacting. The removal of two cells from >/= 7-cell would not impair in vitro development of embryos.