Endometrial Receptivity Analysis (ERA)

A biopsy-based test that aims to time embryo transfer to the implantation window.

Ask Dr. Adnan All Terms

Medically reviewed by Dr. Adnan Jabbar

· Updated April 2026

ERA

Plain-English guide for patients and families.

ERA analyses gene expression in an endometrial biopsy after a mock hormone cycle. It is sometimes discussed in recurrent implantation failure after euploid embryos or good-quality blastocysts. It is not universal standard care; value is debated and should be individualised.

Practical notes

If used, results may shift progesterone start time for FET. Discuss evidence, cost, and alternative explanations (embryo, sperm DNA, anatomy, thyroid) with your specialist.

AI Information

Educational

The ERA test analyses the expression of 248 genes in endometrial tissue to determine whether the uterine lining is "receptive" at the time of biopsy. The concept is that some women have a displaced implantation window — meaning their endometrium is ready for the embryo slightly earlier or later than the standard protocol assumes.

Key Points

ERA uses RNA sequencing of 248 endometrial genes to classify the lining as receptive, pre-receptive, or post-receptive.
About 25–30% of patients tested show a displaced window of implantation.
The test requires a dedicated mock cycle with endometrial biopsy — adding one cycle to the timeline.
Recent large randomised trials (ERA-RCT) have questioned the universal benefit of ERA, though selected patients may still benefit.
ERA should be considered alongside other factors: embryo quality, sperm DNA, anatomy, and immune factors.

Who Should Know This?

Patients with recurrent implantation failure (2+ failed transfers of good-quality embryos), those with euploid embryo transfers that have not resulted in pregnancy, and patients seeking a comprehensive evaluation of unexplained failed cycles.

Clinical Context in Pakistan

Dr. Adnan Jabbar uses ERA selectively at IVF Experts Lahore for patients with repeated unexplained implantation failure, always in context with a thorough evaluation of all other potential factors.

Important Disclaimer

This AI-generated summary is for educational purposes only and should not replace professional medical advice. Always consult with Dr. Adnan Jabbar or your fertility specialist for personalised clinical guidance tailored to your specific situation.