The ERA test is rated red by the UK regulator, meaning no evidence it improves live birth rates. A large randomised trial found no benefit, and one study found lower live birth rates after ERA-guided transfer following a previous failure.
Why does IVF fail?
Start with the arithmetic, not the investigation
Before looking for a cause, establish what the expected chance actually was. Three failed transfers at 40 with untested embryos may be entirely within expectation. Three failed euploid transfers at 32 is genuinely unexpected.
A substantial proportion of couples labelled with implantation failure have simply not yet had enough good-quality embryos transferred for success to have been likely. The right response then is continuing, not investigating.
The most common reason
Embryo chromosomal abnormality. This is a normal biological phenomenon that increases with egg age. It is not caused by anything you did, and it is why a good-looking embryo on the screen can still fail.
ASRM (2026) gives a useful marker: aneuploidy is found in around 50% of tested miscarriages in women under 35 and 75% in women over 40.
Other contributors worth investigating
Uterine cavity — polyps, submucosal fibroids, adhesions, septum. Hysteroscopy is the highest-yield single investigation and should come before anything more exotic.
Chronic endometritis — though note that ASRM (2026) reports a high-quality randomised trial of 438 women showing no benefit from doxycycline in recurrent pregnancy loss, which tempers confidence in test-and-treat here too.
Endometrial preparation — particularly luteal support adequacy in programmed cycles, a recognised and correctable cause.
Laboratory factors — fertilisation rates, blastulation rates, and whether the unit is meeting its performance benchmarks. Systematic laboratory issues present as individual patients failing.
Sperm DNA fragmentation in selected cases — not in initial evaluation.
Thyroid function and antiphospholipid antibodies.
What is NOT supported
Endometrial receptivity testing (ERA) — rated red by the UK regulator, meaning no evidence it improves live births. A large randomised trial found no benefit, and a 2022 study found live birth rates were lower after ERA-guided transfer following a previous failure.
Immunological testing and treatment — NK cell assays, intralipids, IVIG, steroids.
Inherited thrombophilia screening — a systematic review found prevalence in women with recurrent loss is the same as in the general population.
Endometrial scratch.
Couples at this stage are highly motivated to try anything, which makes candour more important rather than less.
What to do after a failure
Ask for a debrief before asking for tests. Understanding what happened at each stage — eggs collected, fertilised, embryo development day by day, lining response — usually points to what to change, and many people do not realise they can request it.
Protocol changes are frequently more valuable than added tests.
Frequently Asked Questions
Why did my IVF fail with a good embryo?▾
The most common cause is chromosomal abnormality in the embryo -- standard grading cannot detect this. Even a 4AA blastocyst has a 30-50% chance of being aneuploid depending on your age. Other causes: displaced implantation window (ERA test), subclinical endometritis, elevated sperm DNA fragmentation, uterine abnormalities, or antiphospholipid syndrome. After 2 failed good-quality embryo transfers, a structured investigation covering all these areas is recommended by ESHRE and ASRM 2023.
What is recurrent implantation failure (RIF)?▾
Recurrent implantation failure is defined as failure to achieve a clinical pregnancy after 2 or more transfers of good-quality embryos in a woman under 40. It affects approximately 10% of IVF patients. Investigation should include: hysteroscopic uterine cavity evaluation, sperm DNA fragmentation testing, ERA endometrial biopsy, chronic endometritis biopsy, antiphospholipid antibody panel, and PGT-A on remaining embryos.
Does a chemical pregnancy after IVF mean it is working?▾
A chemical pregnancy (positive hCG that does not develop into a clinical pregnancy on ultrasound) confirms implantation occurred -- a positive sign. It typically indicates a chromosomally abnormal embryo that implanted briefly before arresting. After a chemical pregnancy, PGT-A testing of remaining embryos is strongly recommended to identify chromosomally normal embryos for subsequent transfers.
How many failed IVF cycles before investigation?▾
ASRM and ESHRE 2023 define Recurrent Implantation Failure as 2 or more failed transfers with good-quality embryos -- this triggers full investigation. Do not continue cycles without investigating why previous ones failed. After thorough investigation and treatment of any identified cause, cumulative success rates remain meaningful across further cycles.