Early human embryos are naturally aneuploid—can that be corrected?

Abstract

Aneuploidy is common and may be a natural occurrence in early human embryos. Selecting against embryos containing aneuploid cells for embryo transfer has been reported to increase clinical pregnancies per transfer in some studies, but not others. Some aneuploidy is due to misallocation of chromosomes during meiosis, in either the egg or sperm, but most aneuploidy is due to misallocation of chromosomes during mitoses after fertilization. Big questions are as follows: Why does this happen? How much aneuploidy in a preimplantation embryo is compatible with normal fetal development? Is aneuploidy increased by in vitro culture, and/or could it be prevented or corrected in the IVF lab?