The effect on cleavage of two-cell mouse embryos after a delay in embryo retrieval in a human in vitro fertilization...

Two-cell mouse embryos are used for quality control in a human in vitro fertilization programme. A controlled experiment was designed to evaluate the effect on cleavage of two-cell mouse embryos after a delay in embryo retrieval. In the test group, two fallopian tubes were incubated in Whittingham's T6 medium for 2 1/2 hours per experiment before the embryos were removed for culture. In the control group embryos were removed from the fallopian tubes immediately after the mice were sacrificed. Five experiments were performed. Eight of 141 two-cell embryos (5,7%) reached the blastocyst stage in the test group, and in the control group 143 of 151 two-cell embryos (94,7%) reached the blastocyst stage after 72 hours. Embryos must be removed immediately after the mice are sacrificed to obtain constant results. If not, poor cleavage can lead to unnecessary confusion in the laboratory.