I presented on the topic of recurrent implantation failure at our annual Fertility Society of Australia and New Zealand conference in Perth in 2024.

There was a study published that showed that with the transfer of three embryos that were tested to be genetically normal (using PGT-A), the cumulative live birth rate was 95% (1). A subsequent study showed that with the transfer of five embryos that were tested to be genetically normal (using PGT-A), the cumulative live birth rate was 98% (2).

The authors concluded that recurrent implantation failure, if it does exist, exists in less than 5% of cases.

What does this mean?

• Even when all known causes that reduce the chances of pregnancy are excluded, the IVF cycle has been optimally conducted and a genetically tested normal embryo is transferred, this is still a 35% chance of the pregnancy failing to implant.

• It may take the transfer of several genetically normal embryos until you have very good chance of having an ongoing pregnancy.

• It also means that even if your previous transfers have been unsuccessful, this does not harm your chances of having an ongoing pregnancy in your subsequent transfers.

• The authors of the above studies concluded that it is likely the embryo that determines the implantation success rates, though an endometrial factor cannot be ruled out.

We should always look at optimizing your chances by excluding known causes that reduce the chances of pregnancy.

Undergoing fertility treatment can entail a rollercoaster of emotions, but it can help to have realistic expectations from the start. You may get lucky with the first embryo transfer, and this is what we all hope for. However, the data suggests that it may take several embryo transfers to have a really good chance of pregnancy.

References:

• Pirtea, Paul et al, ‘Rate of True Recurrent Implantation Failure Is Low: Results of Three Successive Frozen Euploid Single Embryo Transfers’ (2021) 115(1) Fertility and sterility.

• Gill P, Ata B, Arnanz A, et al. Does recurrent implantation failure exist? Prevalence and outcomes of five consecutive euploid blastocyst transfers in 123 987 patients. Human Reproduction. 2024;39(5):974-980.