chapter  7
6 Pages

Clinical Results: Dynamic Aspects – Fragmentation

BySue Montgomery

Fragmentation has been shown to be related to reduced viability and blastocyst formation rates, when more than 15

Figure 7.1 Fragmentation usually arises at the first cleavage division. (Timings: row 1, panel 1, 25.2 h; row 2, panel 1, 26.5 h; row 3, panel 1, 27.9 h.)

5,6 It is currently not possible to distinguish in a cohort of fragmented embryos, which embryos are capable of implanting. It is possible that the release of large fragments at the cleavage stage may deplete the embryo of essential organelles, such as mitochondria (essential for normal cleavage) or polarized membrane constituents.4 However, it has also been suggested that this may vary according to the pattern of fragmentation.7 In Alikani’s categorization, scattered large fragments that were indistinguishable from cells were specifically associated with a significantly lower blastocyst formation rate.