The oviduct and development of the preimplantation embryo

Abstract

Fertilization and early embryo development take place in the oviduct in vivo. Relative to studies in other reproductive organs, the importance of the oviduct has been ignored for many years because pregnancies can be obtained in assisted reproduction treatment using in-vitro fertilization (IVF) and embryo transfer to the uterus without involving the Fallopian tube. After the reports on the beneficial effect of oviductal cells on embryo development in sheep and subsequently in human, and a practical need to improve the success rates in clinical assisted reproduction, there was a period when more research was performed on the Fallopian tube. Many of these studies used in vitro coculture systems to emulate the in vivo environment in vitro, and to search for oviduct-derived embryotrophic factors. With the recent development of sequential culture to improve embryo development in vitro, the use of coculture in assisted reproduction and its related research declined because routine use of coculture is laborious and experience-dependent.