A 2026 meta-analysis found no benefit of ERA or other endometrial receptivity tests in general IVF patients, with a possible improvement in live birth for RIF patients transferring untested embryos.
Endometrial receptivity tests, like the ERA and other platforms, analyze gene activity in the uterine lining to estimate the best time for transfer. If the lining is labeled “non-receptive,” the timing of the embryo transfer may be adjusted in a future cycle.
The idea is that some patients could have a shifted “window of implantation,” and correcting the timing could improve implantation.
A meta-analysis by Glujovsky et al. (2026) combined the results of 44 studies to see if the these endometrial receptivity tests improve live birth rates.
In 2022, a smaller meta-analysis of 8 studies (mostly retrospective) found no difference in live birth, clinical pregnancy, or miscarriage rates with ERA use. Since then, more than 20 additional studies, including new randomized trials, have been published. Read more in my post: Meta-analysis finds no difference in pregnancy outcomes when using the ERA.
🔗 Original studies are referenced in this post or within the linked Remembryo posts.
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Study details
- Study design: Systematic review and meta-analysis of 44 studies (4 randomized controlled trials, 6 prospective studies, 34 retrospective studies) published between 2018 and 2025 mainly across China, the US and Spain.
- Participants: Thousands of women undergoing IVF or ICSI; included both general IVF patients and those with recurrent implantation failure (definitions varied, but mainly 2-3 or more failed transfers). No age limits or restrictions on diagnosis.
- Intervention: Personalized embryo transfer guided by endometrial receptivity tests (ERA, rsERT, ERT, ERPeak, WIN-Test). Most studies involved ERA.
- Transfer type: Included both untested and PGT-A (euploid) cycles
- Primary outcome: Live birth rate per woman
Randomized trials find no difference
This meta-analysis included 44 studies, four of which were randomized controlled trials (the strongest type of study). However, only two were considered reliable enough to be combined in the meta-analysis. The other two had important design concerns and weren’t included in the pooled results.
When these two trials were combined, with non-RIF patients and the ERA test, receptivity-guided transfer didn’t improve outcomes compared to standard timing:
- Live birth rate: no difference between receptivity-guided transfer and standard timing (52.9% vs 53.7%, risk ratio [95% CI]: 0.98 [0.88-1.10], 2 RCTs, 1069 participants, I2= 39%)
- Cumulative live birth rate: no difference (risk ratio [95% CI]: 1.12 [0.92–1.36]; 1 trial)
- Clinical pregnancy rate: no difference (risk ratio [95% CI]: 0.99 [0.91–1.08]; 2 trials)
- Miscarriage rate: no difference (risk ratio [95% CI]: 1.04 [0.69–1.58]; 2 trials)
Even when all four RCTs were combined, including those with design concerns, there was still no clear benefit (relative risk [95% CI]: 1.08 [0.98-1.19], 4 RCTs, 1468 participants, I2= 84%).
Non-randomized studies find some improvement for RIF patients without PGT-A
Besides the randomized trials above, this review also included 40 additional studies. Most were retrospective, with a few prospective cohort studies.
These studies were not randomized, so they are more prone to bias. The authors analyzed them separately and divided patients into different groups based on whether they had RIF, if PGT-A was used, and the type of receptivity test used.
In RIF patients, results differed depending on whether embryos were tested with PGT-A:
- In RIF patients without PGT-A, receptivity-guided transfer was associated with higher live birth rate (47.2% vs 36.1%, odds ratio 1.59 [1.31–1.91], 9 studies, 5794 participants, I2= 16%). When analyzed by test type (ERA, rsERT, and ERT), each platform showed a similar benefit.
- In RIF patients with PGT-A, there was no difference in live birth rate (odds ratio 1.36 [0.83–2.22]).
In non-RIF patients, the results were also inconsistent and didn’t show a clear or reliable improvement in live birth.
Conclusion
This updated meta-analysis found:
- In randomized trials (the strongest type of study), they found no benefit for general IVF patients without RIF.
- In weaker, non-randomized studies, higher live birth rates were seen in RIF patients who transferred untested embryos. In RIF patients who transferred euploid embryos after PGT-A, no benefit was found.
The authors note that if endometrial receptivity tests actually had a strong benefit, we would expect to see the clearest effect when only euploid embryos are transferred. When embryos are already confirmed to be chromosomally normal, the embryo is less likely to be the reason a transfer fails, so any real timing effect should be easier to see. The fact that the benefit mainly appears when embryos are untested suggests that the improvement may not be due to timing alone.
The authors suggest two possible explanations for the mixed results:
- One is that only a small subgroup of RIF patients exists that truly have a shifted window of implantation, who would benefit from adjusting transfer timing. If that group is small, it could be hard to detect unless larger studies are done.
- The other possibility is that any benefit could be driven more by bias and differences in care. Patients who have receptivity testing might be more closely monitored or have more optimized treatment with their clinic. If that’s the case, the test itself might not be the reason for improved outcomes.
Overall, the strongest studies don’t support routine receptivity testing for most IVF patients. There might be some benefit in RIF patients with untested embryos, but this is uncertain. Larger, well-designed studies are still needed.
Limitations include that there were only two high-quality RCTs, reliance on lower quality data for RIF patients, differences in how RIF is defined, no data on interchangeability between different receptivity tests.
Want to read more about endometrial receptivity?
Researchers in a 2022 study performed a meta-analysis to combine the results of 8 ERA studies and found no differences in live birth, pregnancy and miscarriage rates among women who performed the ERA or didn't. Read more.
Researchers in a 2024 study found that patients that have 5 consecutive euploid transfers had a cumulative live birth rate of 98.1%, suggesting that most cases of implantation failure are due to the embryo, and that true unexplained RIF occurs in less than 2% of patients. Read more.
Researchers in a 2022 study found no difference in live birth rates in those that transferred embryos by standard timing or timing established by the ERA. Read more.
Reference
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.
Related posts:
Complete guide to embryo implantation and implantation failure
Meta-analysis finds no difference in pregnancy outcomes when using the ERA
RCT finds no change in birth rates for standard or ERA-timed euploid transfer
Why do embryos in IVF fail to implant or miscarry?
Meta-analysis examines impact of small fibroids on pregnancy outcomes
Intrauterine hCG for IVF patients improves pregnancy rates
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