The ERA Test: Finding Your Perfect Window of Implantation

The Window of Implantation: The lining of the uterus (endometrium) is not always ready to accept an embryo. Following ovulation (or progesterone exposure in an IVF cycle), a cascade of genetic changes occurs in the lining, opening a brief 'window of implantation'—typically lasting only 24 to 36 hours. In about 70-75% of women, this window occurs exactly when expected (after 5 days of progesterone). However, in 25-30% of women, this window is 'displaced'—meaning it opens earlier or later. If an embryo is transferred outside this specific window, implantation will fail, regardless of the embryo's quality. What is the ERA Test? The Endometrial Receptivity Analysis (ERA) is a diagnostic test that evaluates the expression of 236 genes related to endometrial receptivity to find your precise window. How is it done? 1. A 'Mock' Cycle: You prepare your lining using exact same estrogen and progesterone medications you would use for a frozen embryo transfer. 2. The Biopsy: Instead of transferring an embryo on 'Transfer Day', Dr. Ankita performs a quick in-office endometrial biopsy taking a tiny sample of the lining. 3. The Analysis: The tissue is genetically sequenced to determine if the lining was 'Pre-receptive' (needs more progesterone), 'Receptive' (perfect timing), or 'Post-receptive' (needed less progesterone). 4. The Real Transfer: In your actual transfer cycle, we adjust the timing of your progesterone administration down to the specific hour based on the ERA results. Who should get an ERA? While some clinics offer it to everyone, Dr. Ankita typically recommends it for: - Patients who have experienced Recurrent Implantation Failure (2+ failed transfers of good embryos) - Patients who have only one or two precious PGT-A tested normal embryos and want to eliminate all variables before transfer. - Patients with a history of severe endometriosis or adenomyosis, which are known to alter receptivity.