The Poor Performance of Neu5Gc for Endometrial Receptivity in Embryo Transfer

Abstract

Neu5Gc is a common sialic acid in mammals, but humans cannot synthesize it independently. When Neu5Gc in the diet enters the body, the body produces antibodies against Neu5Gc, which in turn promotes the immune response and chronic inflammation and may be closely related to embryo transfer rejection. Therefore, Neu5Gc has gained widespread interest from gynecologists, nutritionists, and immunologists. The same problem occurs during embryo transfer, where the embryo carries paternal gene products and is a hapten relative to the maternal endometrium. Successful implantation requires a receptive endometrial environment. Moreover, with the widespread application of in vitro fertilization and embryo transfer technology, nonhuman amino acids may be introduced into the embryo culture medium, mainly the genetic engineering-derived essential serum albumin in embryo culture medium, which may introduce the nonhuman sialic acid Neu5Gc and cause embryo transfer rejection.