ASRM releases 2026 guidelines on recurrent implantation failure

The ASRM published their 2026 guidelines on recurrent implantation failure (RIF), introducing a new definition of RIF and reviewing which tests and treatments may be considered after repeated failed embryo transfers.

The American Society for Reproductive Medicine (ASRM) is an authority on reproductive medicine that releases committee opinions and guidelines on fertility-related topics. Their latest committee opinion focuses on recurrent implantation failure (RIF).

RIF has traditionally referred to repeated embryo transfers that fail to result in pregnancy, but there has been no universally accepted definition. Studies have used different numbers of failed transfers, embryo stages, and definitions of implantation, making the research difficult to compare.

The ASRM developed this committee opinion to provide a more standardized definition of RIF and an evidence-based approach to its evaluation and management.

Many of the recommendations are based on observational evidence and expert consensus because high-quality randomized trials in patients with RIF are lacking. Importantly, many tests and treatments are not recommended because there isn’t enough evidence that they work, rather than because evidence shows they don’t work. Recommendations may change as new evidence becomes available.

To learn more about implantation failure, see my post Why do embryos in IVF fail to implant or miscarry?

---

How does ASRM define recurrent implantation failure?

The ASRM defines RIF as failed implantation after transferring enough good quality blastocysts to reach an expected 95% cumulative chance of a positive pregnancy test.

“Cumulative” means the chance across multiple embryo transfers, rather than the chance from a single transfer. For example, the 3–6 euploid embryos described below would typically be transferred one after another in separate single embryo transfers, with the overall chance of implantation accumulating across those attempts.

Based on current research, ASRM estimates that RIF may occur after approximately 3–6 failed euploid embryo transfers. For untested embryos, the number depends on age because embryo aneuploidy becomes more common with increasing maternal age.

Age	Euploid embryos	Untested embryos
<35	~3–6	~5–9
35–37	~3–6	~5–11
38–40	~3–6	~8–18
41–42	~3–6	~14–26
>42	~3–6	~30–43

In my opinion, these estimates should be interpreted cautiously, particularly for older patients using untested embryos, for several reasons:

• The numbers are based on mathematical modeling, not observed transfer outcomes. ASRM based its estimates for untested embryos on age-related aneuploidy data and mathematical modeling. One of the studies cited, Ata et al. (2021), modeled how many embryos would need to fail before embryo aneuploidy alone became an unlikely explanation. The authors themselves described the estimated number for women over 42 as “impractically large.”
• The outcome does not match ASRM’s new definition. ASRM defines implantation using a positive hCG pregnancy test, while the estimates in the figure are based on sustained implantation (clinical pregnancy). ASRM acknowledges that data using hCG for this definition are not available and that the figure may therefore overestimate the number of failed transfers needed.
• The estimates may be unrealistic if interpreted as clinical thresholds. For patients over 42 using untested embryos, the figure estimates approximately 30–43 failed blastocyst transfers. Most patients would never undergo this many transfers, yet they could technically remain below ASRM’s statistical threshold for RIF.

Until these estimates are calculated using positive hCG as the outcome, they should be interpreted cautiously and may overestimate the number of failed transfers needed to meet ASRM’s new definition.

ASRM also does not clearly define what counts as a “good quality blastocyst,” including how embryo grade or the day an embryo reaches the blastocyst stage should be considered. These factors can affect the chance of implantation and could therefore change how many failed transfers would be expected.

ASRM’s approach to recurrent implantation failure

When RIF is suspected, ASRM recommends reviewing the patient’s history, imaging, and previous IVF cycles for possible causes. If nothing treatable is found, extensive additional testing may not be needed, and continuing embryo transfers may be reasonable.

Tests and treatments to consider when RIF is suspected

• Repeat uterine and tubal evaluation
  • Evaluation with saline sonohysterography (SHG), hysteroscopy, HSG, or 3D ultrasound may be considered.
  • Removal of endometrial polyps and submucosal fibroids may be reasonable, although evidence that this improves live birth in RIF is lacking.
• Parental karyotyping
  • May be considered to look for structural chromosome rearrangements.
  • If a chromosome abnormality is identified, genetic counseling and PGT-SR may be considered.
• PGT-A
  • May be considered after RIF with untested embryos to investigate whether embryo aneuploidy may be contributing to the failed transfers.
  • The ASRM states that there is currently no evidence that PGT-A increases live birth rates in patients with RIF.
• Chronic endometritis testing and treatment
  • Testing and/or antibiotic treatment may be considered, although diagnostic criteria vary and evidence that treatment improves live birth rates remains inconclusive.
  • Some observational evidence suggests confirming that chronic endometritis has resolved after treatment may be useful.
• Endometriosis and adenomyosis treatment
  • Based on limited evidence, pretreatment with a GnRH agonist and an aromatase inhibitor may be considered before embryo transfer.
  • BCL-6 testing is not routinely recommended because evidence of its usefulness is conflicting. BCL-6 is one of the markers measured by the ReceptivaDX test.
• Embryo transfer technique
  • Although evidence is not specific to RIF, the ASRM recommends following its existing evidence-based embryo transfer guidelines (ASRM 2017).
  • Cervical stenosis is the most common cause of a difficult embryo transfer, and cervical dilation before transfer may improve pregnancy rates in patients with a history of difficult transfers, although evidence is limited.

Tests and treatments not routinely recommended for RIF

• Endometrial receptivity testing (ERA)
  • There is not enough evidence that the ERA improves live birth rates in patients with RIF.
• Sperm DNA fragmentation testing
  • There is insufficient evidence to recommend sperm DNA fragmentation testing specifically for RIF.
• Endometrial scratching
  • Evidence suggests that endometrial injury does not improve outcomes and is not recommended for treating RIF.
• Antiphospholipid syndrome (APS) testing and anticoagulation
  • There is insufficient evidence to support routine APS testing in women with RIF.
  • Routine anticoagulation with heparin or low molecular weight heparin is not supported for RIF without APS.
• Immune therapies
  • There’s insufficient evidence for intralipids, G-CSF, intrauterine hCG, TNF-α inhibitors and intrauterine PRP for RIF.
  • IVIG is not recommended.
• Specific progesterone supplementation protocols
  • There is not enough evidence to recommend a specific progesterone supplementation protocol for patients with RIF.

Conclusion

ASRM’s new guidelines provide a more consistent approach to defining and managing RIF, but there are still important gaps in the evidence. Studies have used different definitions of RIF, making them difficult to compare, and many tests and treatments have not been well studied specifically in patients with RIF.

These recommendations are also intended for patients after RIF is suspected, not as routine screening before a first embryo transfer. Many tests and treatments are not routinely recommended because there isn’t enough evidence that they improve outcomes in RIF, rather than because they have been proven not to work.

---

Want to read more about RIF and implantation failure?

Reference

Practice Committee of the American Society for Reproductive Medicine. Recurrent implantation failure: a committee opinion. Fertil Steril. 2026;126(2):277-293. doi:10.1016/j.fertnstert.2026.03.026

 

---

About Embryoman

Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.

---