With an embryo transfer, your whole life really can change in a “flash.” So what is this quick flash of light that we see during the embryo transfer? Is it the embryo? First, let’s talk about what happens during the embryo transfer procedure. Typically, a catheter is inserted through the vagina and cervix into the uterus using an abdominal ultrasound as a guide. You can sometimes see this catheter moving through the cervix into the uterus on the ultrasound screen (it appears as a white line). So