Effect of different exposure periods to the infrared 1.48 m diode laser on the inner cell mass and trophectoderm of blastocysts.

ABSTRACT

This study was carried out to determine the effect of the duration of exposure to an infrared 1.48 mm diode laser, on the number of cells in the inner cell mass and the trophectoderm of blastocysts following laser-assisted embryo biopsy. A total of 102 mouse embryos were used in the study. The embryos were randomly divided into three groups; group A (n = 22), group B (n = 47) and group C (n = 33). The embryos in group A were biopsied using the laser with an exposure of 600 ms, whereas those in group B were biopsied using the same laser with an exposure of 5 ms. The embryos in group C were incubated in culture without any procedures, as a control group. The blastocyst formation rates of group B (46/47, 97.8%) and group C (33/33, 100%) were significantly higher than that of group A (12/22, 54.5%). The number of cells in the inner cell mass, trophectoderm and the total number of cells in the blastocyst in group A (16.1 ฑ 5.1, 35.5 ฑ 10.9, 51.6 ฑ 12.9) were similar to those in group B (14.0 ฑ 5.6, 36.0 ฑ 12.7, 50.0 ฑ 18.3). The number of cells in the inner cell mass, trophectoderm and the total number of cells in the blastocysts in group C (19.1 ฑ 6.5, 45.8 ฑ 14.0, 65.0 ฑ 18.7) was significantly higher than those of the study groups. In conclusion, the longer duration of exposure to the infrared 1.48 mm diode laser might adversely affect blastocyst formation. However, it might not affect the quality of the blastocysts with regard to the number of cells in the inner cell mass and the trophectoderm.