A ‘mock’ programmed cycle is staged with approximately two weeks of natural oestrogen to conduct an ERA test. An additional 5 full days of natural progesterone is added, following which an endometrial biopsy is performed. This is done at the LH+7 stage of the woman’s natural cycle or P+5 (start of progesterone + 5 days) in a woman’s hormone replacement programmed cycle.

A biopsy consists of a small tissue sample obtained from the uterine lining and is then examined in the laboratory to understand uterine receptivity better.