Abnormal Cleavage (AC)
Definition - What does Abnormal Cleavage (AC) mean?
The term abnormal cleavage refers to an incorrect division of blastomere cells. Instead of two, it results in the formation of three daughter cells from the mother blastomere cell. Embryos that undergo abnormal cleavage can have the incorrect number of chromosomes and fail to develop into the blastocyst stage.
FertilitySmarts explains Abnormal Cleavage (AC)
Cleavage is a rapid division of cells that takes place after the egg fuses with the sperm. Development to the blastocyst stage confirms that the embryo is still growing and has a chance of successfully implanting if transferred to a uterus.
Embryos with an abnormal cleavage often fail to develop to the blastocyst stage and cannot be transferred because of their extremely low potential for implantation.
Abnormal cleavage is thought to be due to an abnormal arrangement of the mitotic spindle which leads to abnormal separation of chromosomes.