What ERA Testing Measures
Synchronizing the developmental stage of the embryo with the receptivity of the uterine lining.
We want to give patients who visit our Virginia fertility center the best chance of having a successful pregnancy. Endometrial receptivity array testing, also called ERA testing, helps us achieve this by indicating the exact optimal time to transfer an embryo to the uterus.
The timing of embryo transfer is vital because the embryo must implant into the uterine lining (the endometrium) as the critical first step in a successful pregnancy. Implantation is a complex molecular dialogue between embryo and uterine tissue, and precision timing is essential. When our fertility specialist transfers an embryo to a patient’s uterus, the embryo is at a blastocyst stage of development when it is prepared to release the biochemical signals necessary for implantation.
Ideally, when the embryo is transferred to the uterus, the endometrium is also physically and chemically receptive. However, research has demonstrated that, for some women, the endometrium is not at peak receptivity when conventional clinical schedules expect it to be. If the endometrium is non-receptive, the embryo may not implant at all, or it may implant weakly, resulting in early chemical pregnancy or miscarriage.
The Progesterone Exposure Window
For most women, the endometrium is receptive precisely 6 days (approx. 120–124 hours) after starting progesterone during a programmed frozen embryo transfer (FET) cycle. However, clinical studies show that some women require only 5 days of progesterone (pre-receptive on day 6), while others require 7 days (post-receptive on day 6) before the embryo is transferred. ERA testing precisely determines your unique progesterone requirement.
How Igenomix ERA Testing Works
Overcoming endometrial dyssynchrony through molecular genetic profiling.
Reproductive endocrinologists refer to the condition where an embryo is ready to implant but the endometrial lining is out of sync as dyssynchrony—a timing mismatch between embryo development and uterine readiness. Our Virginia fertility center utilizes the gold-standard Igenomix ERA test to diagnose and correct dyssynchrony.
Endometrial Biopsy in a Mock Cycle
During a natural or hormone-induced mock cycle, our fertility specialist administers estrogen and progesterone to prepare the uterine lining exactly as if a transfer were taking place. A quick, minimally invasive biopsy collects a small sample of endometrial tissue when the lining is standardly expected to be receptive.
248-Gene RNA Expression Analysis
Specialized molecular genetics technicians extract RNA from the biopsy sample and analyze the expression levels of 248 specific genes regulating uterine receptivity to determine if the tissue is pre-receptive, receptive, or post-receptive.
Comprehensive Molecular Report & pET
The resulting diagnostic report identifies your exact window of implantation (WOI). If a displacement is detected, Dr. Fady Sharara customizes your progesterone timing down to the hour for a Personalized Embryo Transfer (pET) during your subsequent live FET cycle.
ERA Testing Promotes Pregnancy Success
Transforming outcomes for patients facing recurrent implantation failure (RIF).
Recent peer-reviewed research demonstrated that a significant percentage of women who have experienced at least one failed implantation despite transferring high-quality, euploid (genetically normal) embryos were experiencing endometrial dyssynchrony.
Higher Implantation Rates
Transferring the embryo during the validated receptive window dramatically increases the likelihood of robust embryo attachment and healthy placenta formation.
Protects Valuable Embryos
Prevents the tragic loss of precious, genetically tested embryos by ensuring the uterine environment is primed before the transfer takes place.
Overcomes Failed IVF Cycles
Provides clear, actionable biological answers for couples diagnosed with unexplained recurrent implantation failure (RIF).
Truly Personalized Care
Replaces standardized, one-size-fits-all transfer schedules with an individualized protocol tailored to your unique reproductive genetics.
In clinical studies, personalized embryo transfers based on an ERA-identified window of implantation resulted in significantly higher pregnancy and live birth rates, equalizing outcomes with normal receptive patients.
Frequently Asked Questions About ERA Testing
Important details about the procedure, comfort, timing, and candidates.
Who is an ideal candidate for ERA testing?
ERA testing is strongly recommended for women with one or more failed IVF embryo transfers (especially with genetically normal euploid embryos), recurrent early pregnancy loss, or patients who have a limited number of embryos and want to maximize the success of their first transfer.
Does the endometrial biopsy hurt?
The biopsy takes only 10 to 15 seconds. Patients may experience brief menstrual-like cramping. We recommend taking a mild analgesic like ibuprofen beforehand to ensure maximum comfort.
Can ERA testing be combined with other endometrial tests?
Yes. The same biopsy sample can also be evaluated with EMMA (Endometrial Microbiome Metagenomic Analysis) to assess healthy uterine bacteria and ALICE (Analysis of Infectious Chronic Endometritis) to detect chronic inflammation or bacterial pathogens.
How long do ERA test results remain valid?
ERA test results are generally valid for several years as long as the patient's body mass index (BMI), uterine anatomy, and hormonal protocol remain consistent.