Recurrent Implantation Failure: What's Actually Going On

You have transferred three or more embryos, at least one of them euploid and possibly all of them, and none have produced a sustained pregnancy. Maybe one was a chemical. Maybe two looked like they would take and then did not. You have heard your RE use the words "recurrent implantation failure" or "RIF" and you are reading because you want to understand what they will actually investigate, which add-ons to refuse, and what realistic next steps look like.

Three failed transfers is not just three failed transfers. It is three pregnancy losses in different forms, biochemical, missed, or never-implanted, and the grief compounds. Recurrent implantation failure is a clinical label, and the label can feel heavier than the embryos themselves. The diagnostic process can start to feel like being made a project, which is a feeling worth naming and not pushing past. Take what you can use from this post. Leave the rest for later, or for never.

The 2023 ESHRE definition of recurrent implantation failure

For most of the 2010s, recurrent implantation failure (RIF) was loosely defined as "two or more failed transfers." That definition was too loose. It pulled in patients with bad luck across two transfers and routed them toward intensive, expensive, often non-evidence-based workups.

In 2023, an ESHRE working group published good practice recommendations that redefined RIF more tightly. The current definition: failure to achieve a clinical pregnancy after transfer of at least three high-quality embryos, OR the equivalent number of euploid embryos, in a person under 40.¹

Three things matter about this definition.

First, it uses the number of high-quality or euploid embryos, not the number of transfers. A patient who transferred three day-7 low-grade untested blastocysts is in a different statistical place than a patient who transferred three euploid 4AA day-5 blastocysts. The denominator is embryo quality, not just transfer count.

Second, it carves out the under-40 age band, because over 40 the embryo cohort itself starts to drive failure rates and the workup question shifts toward ploidy and cohort quality rather than implantation specifically.

Third, ESHRE framed this as "good practice recommendations" rather than a strict guideline because the evidence base remains modest. They are signaling that the workup should be careful and proportionate, not maximal.

Why a tighter definition matters

The old definition produced a lot of unnecessary medicine. Patients with two failed transfers of average-quality embryos were being run through immune panels, NK cell biopsies, ERA testing, intralipid infusions, growth hormone, and prednisolone, much of which has weak or null evidence in this population.

A tighter definition does three things:

• It prevents over-investigation in someone whose results fall inside expected probability.
• It directs intensive workup at the patients most likely to actually benefit.
• It gives clinicians a defensible reason to decline add-ons that families have read about online and feel they should be doing.

The shift, in short, is from doing more to doing the right things.

The modern RIF workup, narrowed

When a patient meets the ESHRE definition, the evidence-supported workup runs through roughly seven items. Most of these can be done within a single menstrual cycle.

• Uterine cavity assessment: Hysteroscopy is the gold standard; saline-infusion sonogram (SIS) is the less invasive alternative. The cavity is checked for polyps, submucosal fibroids, intrauterine adhesions (Asherman syndrome), and chronic endometritis.
• Chronic endometritis screen: Endometrial biopsy with CD138 plasma cell staining. Chronic endometritis is present in roughly 30 percent of women with RIF in some series and is treatable with doxycycline.⁶
• Hydrosalpinx: Ruled out with HSG or ultrasound. If present, salpingectomy or proximal occlusion before the next transfer. The Strandell meta-analysis on salpingectomy benefit is one of the more robust findings in the IVF literature.⁷
• Endometrial preparation review: Programmed versus modified natural FET, progesterone level the day before transfer, supplementation strategy.
• Thyroid and prolactin: TSH target under 2.5 for someone trying to conceive. Treat overt thyroid dysfunction.
• Antiphospholipid syndrome screen: Lupus anticoagulant, anticardiolipin, beta-2 glycoprotein, particularly if there is any history of miscarriage or thrombotic events.
• Karyotype of both partners: A balanced translocation in one partner can produce a cohort that is heavily aneuploid, which looks like RIF but is actually a different problem.
• Sperm DNA fragmentation in selected cases: Not universal, but reasonable when fertilization patterns or biochemical losses suggest it.

That is the list. It is shorter than the workup many patients are offered.

What the modern workup does not include

This is the harder list, and it is the more useful one. The following are items that are commonly offered after recurrent transfer failures and that the current evidence does not support as routine workup.

• NK cell testing: Not part of ESHRE's 2023 recommended workup. The peripheral blood NK count does not reliably predict uterine NK behavior, and the link between NK activity and implantation failure remains contested.¹
• ERA (endometrial receptivity array): The Simon et al. 2020 RCT did not show benefit when personalized timing was compared to standard timing.⁴ ERA testing remains widely sold but is not supported by randomized evidence.
• Inherited thrombophilia genetic testing in routine RIF workup: Factor V Leiden, MTHFR variants, prothrombin G20210A. The ALIFE2 trial in 2023 randomized women with recurrent miscarriage and inherited thrombophilia to low-molecular-weight heparin versus no anticoagulation, and there was no improvement in live birth.² The genetic testing is therefore not actionable for this purpose.
• HLA-G testing: Research-only.
• Immune cocktails: Intralipids, IVIG, prednisolone, GM-CSF infusion. ASRM's 2018 immunotherapy guideline advised against routine use in unselected IVF patients.⁵
• Endometrial scratch: The Lensen et al. NEJM 2019 multicenter RCT showed no benefit.³ The practice has fallen out of routine use.

If you are offered any of the above, ask for the specific evidence in this clinical scenario, the cost, and the mechanism being treated. "It can't hurt and might help" is not a clinical answer, particularly at this stage in the journey when patients are most vulnerable to expensive interventions sold on hope rather than data.

What might actually help in RIF

The interventions with reasonable evidence in this population:

• Hysteroscopic correction of polyps, fibroids, or adhesions if found on cavity assessment.
• Salpingectomy or tubal occlusion for hydrosalpinx.
• Chronic endometritis treatment with doxycycline if biopsy is positive.
• Improved embryo selection with PGT-A if not already done, with the caveat that small cohorts may be left with no transferable embryo after testing.
• Single-variable protocol changes per cycle, as discussed in our cycle-two post.
• Donor egg or donor sperm if cohort-level quality is the limiting factor and intensive workup has been negative.

When a patient has three failed transfers, the most evidence-based thing I can do is narrow the workup, not expand it. The add-on industry profits from RIF. Good medicine resists that.

The sperm question

It is worth checking. Sperm DNA fragmentation index (DFI) testing is reasonable after recurrent transfer failures, particularly if fertilization rates were lower than expected or if biochemical pregnancies were the failure pattern. ICSI with morphologically normal sperm selection (IMSI) has limited evidence. Some clinics offer testicular sperm aspiration in severe DNA fragmentation cases, on a case-by-case basis.

The framing matters here. RIF is often presented as a female-side workup, but the embryo is two people, and a thorough modern workup looks at both.

Mental health is part of the workup

This is not soft language. The data is real. Depression and anxiety rates rise sharply after three or more failed transfers, and the Domar et al. dropout literature suggests that psychological burden, not financial constraint and not medical advice, is the most common reason couples discontinue IVF.⁸

Fertility-trained therapists are different from general therapists, and they are worth the search if you can access one. RESOLVE in the US maintains a directory. Some clinics have embedded counselors.

Support groups can help and can also be triggering. Pick the ones where the framing matches yours. Hopeful-tone groups can feel intolerable after the third loss; data-realistic groups can feel cold to others. There is no right answer; there are different fits for different people.

The framing I offer patients at this stage is "make it through the next six weeks." Not "see this through." Six weeks is enough time for the next workup result, the next consult, the next decision. It is short enough to be manageable when the long view is not.

What to ask your RE after the third failed transfer

Bring these to the consult on paper.

1. Do I meet the 2023 ESHRE definition of RIF?
2. What workup have we completed, and what is still recommended?
3. What are you specifically NOT recommending, and why?
4. Are we considering donor egg or donor sperm at this point?
5. Can you refer me to a fertility-trained therapist?
6. What is your honest read on cumulative live-birth probability across the next two or three transfers?
7. What is your clinic's add-on policy? Which add-ons do you decline as a clinic?

The last question is one of my favorites. A clinic that has a clear answer about what they decline to do, and why, is usually a clinic that has thought about evidence carefully.

What you can do tonight

Not much, and that is the honest answer.

Eat something. Drink water. Read this. Do not make any decisions tonight. The cumulative math does not change in the next week. Your nervous system might.

Tell one person what is actually happening. Not the cleaned-up version. The grief at this stage is heavy and often invisible to people outside the clinic, and the cost of carrying it alone is real.

If you have not yet seen a fertility-trained therapist, this is the moment. The decision tree from here is hard, and it is harder without skilled support. RESOLVE's directory and your clinic's referrals are both reasonable starting points. Recurrent implantation failure is medicine you will get help with. The carrying of it is not something you should do alone.

If you need grief content rather than medicine, our setback library is at when-things-dont-go-to-plan/grieving-a-failed-transfer.

What's next

• If you are planning the next transfer with a narrowed workup: /ivf/failed-ivf-transfer-next-steps
• If protocol changes for cycle two-plus: /ivf/second-ivf-cycle-changes
• If the stopping conversation is starting: /ivf/when-doctors-recommend-stopping-ivf
• If donor egg is the path being considered: /when-things-dont-go-to-plan/donor-egg-decision
• If grief is the priority right now: /when-things-dont-go-to-plan/grieving-a-failed-transfer

Sources

1. Cimadomo D, de Los Santos MJ, Griesinger G, et al. ESHRE good practice recommendations on recurrent implantation failure. Human Reproduction Open 2023;2023(3):hoad023. https://doi.org/10.1093/hropen/hoad023
2. Quenby S, Booth K, Hiller L, et al. Heparin for women with recurrent miscarriage and inherited thrombophilia (ALIFE2): an international open-label, randomised controlled trial. Lancet 2023;402(10395):54-61. https://doi.org/10.1016/S0140-6736(23)00693-1
3. Lensen S, Osavlyuk D, Armstrong S, et al. A randomized trial of endometrial scratching before in vitro fertilization. New England Journal of Medicine 2019;380(4):325-334. https://doi.org/10.1056/NEJMoa1808737
4. Simón C, Gómez C, Cabanillas S, et al. A 5-year multicentre randomized controlled trial comparing personalized, frozen and fresh blastocyst transfer in IVF. Reproductive BioMedicine Online 2020;41(3):402-415. https://doi.org/10.1016/j.rbmo.2020.06.002
5. Practice Committee of the American Society for Reproductive Medicine. The role of immunotherapy in in vitro fertilization: a guideline. Fertility and Sterility 2018;110(3):387-400. https://doi.org/10.1016/j.fertnstert.2018.05.009
6. Johnston-MacAnanny EB, Hartnett J, Engmann LL, Nulsen JC, Sanders MM, Benadiva CA. Chronic endometritis is a frequent finding in women with recurrent implantation failure after in vitro fertilization. Fertility and Sterility 2010;93(2):437-441. https://doi.org/10.1016/j.fertnstert.2008.12.131
7. Strandell A, Lindhard A, Waldenström U, Thorburn J. Hydrosalpinx and IVF outcome: cumulative results after salpingectomy in a randomized controlled trial. Human Reproduction 2001;16(11):2403-2410. https://doi.org/10.1093/humrep/16.11.2403
8. Domar AD, Smith K, Conboy L, Iannone M, Alper M. A prospective investigation into the reasons why insured United States patients drop out of in vitro fertilization treatment. Fertility and Sterility 2010;94(4):1457-1459. https://doi.org/10.1016/j.fertnstert.2009.06.020