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Concierge fertility diagnostics · London

Endometrial receptivity array (ERA), gene-expression testing to personalise the embryo transfer window.

The endometrial receptivity array (ERA) measures expression of 238 endometrial genes to identify the personalised window of implantation in patients with recurrent implantation failure. Guides personalised embryo transfer timing in IVF.

See the key facts
A reproductive medicine specialist performing an endometrial biopsy in a private London fertility clinic

Why patients choose us

  • 01

    The right hands

    We route you to a consultant reproductive medicine specialist working with a validated ERA laboratory — the person who performs the biopsy and the lab that reads it decide the answer.

  • 02

    Structured cycle planning

    ERA only helps if the mock cycle timing is right — we make sure progesterone and biopsy day are protocol-perfect.

  • 03

    Independent, and free

    We are paid by no clinic, so the recommendation is impartial and costs you nothing.

Key facts

What ERA is, in six lines.

The essentials, before the detail — what ERA measures, who it’s for, and what it can change.

  • What it is

    238-gene expression assay of endometrial receptivity.

  • Who it’s for

    Used in recurrent implantation failure after IVF.

  • What it personalises

    Identifies the personalised window of implantation.

  • What it requires

    A mock cycle with strictly-timed progesterone.

  • How the sample is taken

    Retrieval by Pipelle endometrial biopsy at a defined day.

  • What the result can change

    Result may shift embryo transfer by 12–24 hours.

The problem

Good embryos, right uterus, wrong hour.

Recurrent implantation failure often isn’t about the embryo — it’s about a receptivity window that doesn’t line up with the standard transfer time. ERA measures exactly when your endometrium is ready.

  • Repeated failed transfers?

    We route you to a specialist who will decide if ERA is the right next test.

  • Good embryos, no implantation?

    We arrange a protocolised mock cycle, biopsy and validated ERA analysis.

  • Planning your next FET?

    We fold the ERA result into a structured plan for your next frozen embryo transfer.

The journey

From consultation to personalised transfer — what happens, in order.

One consultant coordinating from first message to personalised transfer plan.

  1. 01

    Before

    Fertility specialist consultation

    Review of your IVF history, prior transfers, embryo quality and previous investigations to confirm ERA is the right test.

  2. 02

    Before

    Mock luteal cycle with progesterone

    A hormone-replacement cycle mimicking a frozen embryo transfer — oestrogen priming followed by progesterone at the exact planned dose and timing.

  3. 03

    On the day

    Pipelle biopsy at estimated implantation window

    A small endometrial sample taken with a soft Pipelle catheter at the day and hour dictated by your protocol.

  4. 04

    On the day

    Sample sent for gene-expression analysis

    The biopsy is preserved and shipped to an accredited ERA laboratory for 238-gene transcriptomic analysis.

  5. 05

    After

    Report classifies as receptive, pre- or post-receptive

    The result places your endometrium on the receptivity timeline and dictates the personalised transfer window.

  6. 06

    After

    Personalised embryo transfer scheduled

    Your next frozen embryo transfer is timed to the personalised window — often shifted 12–24 hours from standard timing.

  7. 07

    After

    Structured IVF cycle planning

    The full frozen transfer cycle is planned around the ERA finding, with co-testing (EMMA/ALICE) if indicated.

Typical end-to-end: 6–10 weeks, spanning consultation, mock cycle, biopsy, lab and personalised transfer.

What it shows

When ERA is the right test.

ERA answers a specific question — is your endometrium receptive at the standard transfer time, and if not, by how much should the transfer shift. These are the presentations we see most.

  • Receptive endometrium (standard timing)

    Confirms the standard window is right — transfer proceeds as planned.

  • Pre-receptive endometrium (delayed transfer)

    Endometrium not yet receptive — transfer is delayed to catch the window.

  • Post-receptive endometrium (earlier transfer)

    Window has already passed — transfer is brought forward in the next cycle.

  • Chronic endometritis (co-testing)

    ALICE co-testing flags chronic endometritis — treat with antibiotics before repeat transfer.

  • Recurrent implantation failure diagnosis

    Provides a mechanistic explanation when good embryos repeatedly fail to implant.

  • Personalised window of implantation

    Defines the exact hours in which your endometrium is receptive to an embryo.

  • Response to progesterone protocol

    Reveals whether your endometrium responds to progesterone on the schedule assumed by standard IVF.

  • Red flag: chronic endometritis — treat before repeat cycle

    If ALICE identifies chronic endometritis, do not repeat transfer until it has been treated and cleared.

Next steps

What ERA leads to.

The concrete pathways your fertility team will consider once the ERA result is back.

  • Personalised embryo transfer timing

    Frozen embryo transfer scheduled to the ERA-defined personalised window of implantation.

  • Treat chronic endometritis (antibiotics)

    Targeted antibiotic course when ALICE identifies infection-related endometritis.

  • Progesterone-timing adjustment

    Protocol adjustment to progesterone dose, route or start-time based on the ERA result.

  • Combine with EMMA / ALICE microbiome tests

    Add endometrial microbiome (EMMA) and pathogen (ALICE) co-testing to the same biopsy.

  • Assisted-hatching consideration

    For selected embryos where hatching may add value alongside personalised timing.

  • Genetic testing / PGT-A

    Preimplantation genetic testing to remove aneuploidy as a competing cause of failure.

  • Structured IVF planning

    A written plan for the next frozen transfer cycle built around the ERA result.

  • Fertility counselling and support

    Psychological and practical support alongside the medical pathway.

Our vetted London network

A small panel of fertility clinics, we picked them.

Partners across central and greater London. Not listed publicly — introductions are made privately, once we understand your case.

Selection criteria

How we choose every clinic in our network.

A modern London fertility clinic room prepared for an outpatient endometrial biopsy
Reproductive medicine specialists
  • Consultant reproductive medicine specialists with ERA experience

  • Mock cycles protocolised for progesterone timing and biopsy day

  • Samples processed by validated IGENOMIX or equivalent ERA laboratories

  • Onward pathway into personalised frozen embryo transfer and co-testing

Safety, eligibility and red flags

A brief outpatient biopsy — with a specific set of red flags.

ERA is safe and well-tolerated; the practical points are around timing, what the test can and can’t answer, and the co-existing findings that should prompt treatment before a repeat cycle.

  • Pipelle biopsy is a brief procedure

    A soft catheter takes a small endometrial sample in the outpatient clinic — usually under a minute of sampling.

  • Mild cramping is normal

    Period-like cramping during and after the biopsy is expected and short-lived.

  • No general anaesthetic

    The biopsy is performed awake in the clinic room; no sedation required.

  • Timing is everything

    ERA is only interpretable if progesterone and biopsy day match the protocol exactly.

  • Not a first-line test

    ERA is for recurrent implantation failure — it isn’t part of a first IVF cycle.

  • Result changes the transfer, not the embryo

    ERA personalises when to transfer, not which embryo — PGT-A is the separate question.

  • Co-testing on the same biopsy

    EMMA and ALICE can be run on the same sample — worth discussing before the biopsy.

  • A normal result does not guarantee implantation

    A receptive result narrows one cause of failure — it does not rule out embryo, uterine or systemic factors.

  • Bring your full IVF history

    Prior stimulation protocols, embryo grades, transfer timings and previous test results materially sharpen interpretation.

Red flags to discuss with your specialist

  • · Recurrent implantation failure
  • · Chronic endometritis
  • · Failed multiple euploid transfers
  • · Endometrial polyp
  • · Thin endometrium (< 7 mm)
  • · Uterine cavity distortion
  • · Autoimmune disease affecting implantation
  • · Suspected adenomyosis
  • · Poor luteal phase function

Reading your report

An ERA report can look intimidating. It isn’t.

Whatever the finding, the report keeps to the same four parts.

A consultant reviewing an ERA gene-expression report on a clinical workstation at a UK private clinic

A quiet reminder

The report is written for your fertility team, not for you — and that’s normal.

If you would like us to talk you through it before your follow-up, just ask.

  1. 01 Header

    Indication and cycle details

    Your details, the reason for the test, and the exact progesterone protocol and biopsy timing of the mock cycle.

  2. 02 Technique

    Biopsy method and laboratory pathway

    Pipelle catheter details, sample handling, and the ERA gene-expression platform used.

  3. 03 Findings

    Receptivity classification and timing shift

    Whether the endometrium is receptive, pre-receptive or post-receptive — and, if not receptive, by how many hours the transfer should shift.

  4. 04 Impression

    The conclusion: read this first

    The personalised window of implantation, the recommended transfer timing, and any co-test findings — read this first.

Sources

Guidelines and validation studies behind this page.

Last reviewed 2026-07-30 · Next review 2027-07-30 · Reviewed by Pulse Atlas Editorial Board, · Reading time 6 min.

Recognised by major UK insurers

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Cover depends on your policy and clinic; we confirm with your insurer before booking.

Frequently asked

Everything we get asked about the ERA test.

Quick answers on what ERA measures, who it’s for, how the biopsy is done, and how it changes your transfer.

  • What does an ERA test show?

    The endometrial receptivity array measures the expression of 238 endometrial genes to classify your endometrium as receptive, pre-receptive or post-receptive at the moment of biopsy. That tells the fertility team the personalised window of implantation — the exact timing in which your endometrium is ready to accept an embryo.

  • Who should have an ERA test?

    ERA is designed for patients with recurrent implantation failure — typically two or more failed transfers of good-quality embryos. It isn’t a first-line test in a first IVF cycle.

  • How is the biopsy taken?

    A soft Pipelle catheter is passed through the cervix into the uterine cavity to take a small endometrial sample. It is done awake in the outpatient clinic, takes less than a minute of sampling, and typically causes brief period-like cramping.

  • Why do I need a mock cycle?

    ERA measures endometrial receptivity at a precise moment in a hormonally-controlled cycle. A mock cycle — with oestrogen priming and strictly-timed progesterone — recreates the exact conditions of your planned frozen embryo transfer, so the biopsy answer applies to your real transfer.

  • Can I do EMMA and ALICE at the same time?

    Yes. EMMA (endometrial microbiome) and ALICE (chronic endometritis) can be run on the same biopsy sample as the ERA. If chronic endometritis is found, it is treated with antibiotics before the next transfer.

  • Does a receptive result guarantee pregnancy?

    No. A receptive result narrows one cause of failure — it does not rule out embryo, uterine or systemic factors. ERA personalises when to transfer; it doesn’t change which embryo is transferred.

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In practice, in London

The London pathway for endometrial receptivity array

With endometrial receptivity array, the London question is usually about report turnaround and the radiologist reading it — not whether the scan is available. On the NHS, endometrial receptivity array typically sits behind a triage step and a wait that can stretch from a few weeks into months. In London’s private sector, the same appointment often lands within days. That speed matters when symptoms are disrupting work, sleep, or a plan you’d already committed to — and it’s the single most common reason people call us in the first place.

In practice, a private endometrial receptivity array appointment in London means a named consultant, a proper hour in the room (or the equivalent on a video call), and a report you can actually read. Most of the imaging suites and endoscopy units we use sit within a mile of Harley Street or in Chelsea and Fulham, and turnaround on findings is measured in days, not weeks. For endometrial receptivity array specifically, the difference between a routine report and a sub-speciality read is where private care earns its keep.

We’re careful about what a private pathway for endometrial receptivity array can and can’t promise. It can compress a wait, put you in front of a subspecialist quickly, and get a proper report in your hands within a week. It can’t rewrite what the imaging or the bloods say. Setting that expectation up front tends to make the whole experience less stressful.

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