学会発表・論文発表

American Society for Reproductive Medicine (ASRM)(San Francisco）

Comparison of number of cell at the time of confirmation of early cleavage is useful criteria in selecting good embryos.

  • Objective

    Early cleavage is one of the useful criteria in selecting good embryos. However, some embryos are three or more cells at the time of confirmation of early cleavage. We investigated if these embryos had different growth and pregnancy rates compared with two cells or one cell embryos.

  • Design

    retrospective clinical study.

  • Materials and Methods

    We examined 1039 cycles during the period between January 2004 and December 2007. Every embryo was classified one, two, three or more cells at the time of confirmation of early cleavage, 27 hours after insemination and 25 hours after micro injection. We defined three groups, one cell group was defined that all embryos was one cell, two cell group was defined that at least one embryo was two cell, three or more cell group was defined that at least one embryo was three or more cell embryo. The rates of reaching blastocyst and pregnancy rates were compared among three groups.

  • Results

    The rates of reaching blastocyst were 40.9% in one cell group, 60.3% in two cell group, and 30.2% in three or more cell group in IVF. And, the rates of reaching blastocyst were 26.7% in one cell group, 55.9% in two cell group, and 20.0% in three or more cell group in ICSI. Two cell group had a significantly higher rate of reaching blastocyst than the other groups in IVF and ICSI (P＜0.01). The pregnancy rates were 26.4% in one cell group, 36.9% in two cell group, and 5.7% in three or more cell group in IVF (P＜0.01). And, the pregnancy rates were 18.8% in one cell group, 32.0% in two cell group, and 0% in three or more cell group in ICSI (P＜0.01). Two cell group had a significantly higher pregnancy rate than the other groups in IVF and ICSI (P＜0.01).

  • Conclusions

    Three or more cell group had significantly lower rate of reaching blastocyst and pregnancy rate than the other two groups. The present study suggests that the number of cell at the time of confirmation of early cleavage is a useful criteria in selecting good embryos.