What happens to the embryo after IVF embryo transfer?

There are many steps to successful IVF. Many people have a pretty good grasp of the IVF process—up to the point at which an embryo is transferred to the uterus. But what happens then?

Often if IVF embryo transfer is done using ultrasound-guidance, the patient sees a white “flash” from the air surrounding the embryo. Following transfer, these steps have to occur for successful implantation:

1. The embryo enters the uterine cavity as a blastocyst. Within the environment of the uterine cavity, it then hatches.

2. Apposition: The hatched blastocyst comes in contact with the uterine lining.

3. Attachment: The blastocyst then attaches to the uterine lining (luminal epithelium of the endometrium).

4. Invasion: Then, the cells from the outer lining of the blastocyst (trophectodermal cells) penetrate the lining of the uterine cavity (basal lamina). There are local substances (cytokines, macrophages, uterine natural killer or NK cells) that help with invasion. Blood vessels are then invaded and these supply essential nutrients to the developing embryo.

Implantation is an intricate process that requires a host of factor to work together for it to be successful. Even in the best IVF programs, only about 50% of embryos will implant. This is because human reproduction is not very efficient. Successful implantation of an embryo depends not only on embryo quality, but also on endometrial receptivity and the microenvironment for embryo-maternal signaling within the uterine cavity.

To see a Board Certified fertility specialist with a well-established and successful IVF program, make an appointment at one of InVia's four Chicagoland locations.