To ascertain uterine receptivity for the embryo to be implanted, an advanced, personalized, and genetic diagnosis is now undertaken known as Endometrial Receptivity Analysis. This is to understand the environment in the uterus and of the endometrium and ascertain if it is ready for embryo implantation from a molecular point of view.
There are various proteins in the endometrium, produced under the influence of estrogen and progesterone – that help prepare the endometrium for implantation. This includes achieving the right level of thickness and hospitability for the embryo.

The production of all proteins in cells is governed by genetic expressions and will be better understood to ascertain uterine receptivity. Therefore, ERA is the genetic analysis of the expression levels of 238 genes related to endometrial receptivity to arrive at a woman’s optimum time to transfer frozen embryos. For nearly 80% of women, taking progesterone for 5 days, followed by embryo transfer the next day, is the optimal implantation window. The biopsy test evaluates the endometrium’s status and determines whether the woman’s uterus has a receptive gene profile after 5 days of progesterone.