Many authors claimed that an increase in implantation and pregnancy rates has been reported to occur when embryos are transferred to the central area of the uterine cavity but there are no studies about the implantation site after using this type of transfer.
The technique of embryo transfer is thought to affect the implantation and pregnancy rate .At present, the implantation site can be estimated from the location of the very early gestational sac by transvaginal ultrasound.