Embryo transfer to the uterus is the pinnacle of all courses of assisted reproduction treatment. It cannot be left to chance. The endometrium needs to be receptive and facilitate embryo embedding.
The endometrium can be prepared with the aid of drugs (oestrogens) to simulate natural uterine behaviour – a substituted or artificial cycle – or transfer can be carried out whenever biologically most appropriate following ovulation – transfer during a natural cycle. […]
In an in vitro fertilization, embryo transfer takes place in the same cycle in which the ovaries are stimulated and the embryos are generated. However, on many occasions, this is not ideal. The development of several follicles in the ovaries, upon receipt of various stimulus from different follicles, can deconstruct the endometrium and disrupt its implantation capacity. […]