O-100 Recurrent implantation failure
Authors: Macklon N , Cimadomo D , de los Santos Molina M J , Griesinger G , Lainas G , Le Clef N , McLernon D J , Montjean D , Toth B , Vermeulen N 
Published: June 2023

Abstract

Study question
How should Recurrent Implantation Failure (RIF) in ART patients be defined and managed?

Summary answer
This is the first ESHRE good practice recommendations paper providing a definition for RIF and guidance on how to investigate causes and contributing factors and how to improve the chances of a pregnancy.

What is known already
RIF is a challenge in the ART Clinic, with a multitude of investigations and interventions offered and applied in clinical practice, often without biological rational or unequivocal evidence of benefit.

Study design, size, duration
This recommendations document was developed according to a predefined methodology for ESHRE good practice recommendations. Recommendations are supported by data from the literature, if available, the results of a previously published survey on clinical practice in RIF and the expertise of the working group. A literature search was performed in PubMed and Cochrane focusing on “recurrent reproductive failure", "recurrent implantation failure" and "repeated implantation failure“.

Participants/materials, setting, methods
The ESHRE RIF Working Group included 8 members representing the ESHRE Special Interest Groups of Implantation and Early Pregnancy, Reproductive Endocrinology, and Embryology, and completed with an independent chair and an expert in statistics. The recommendations for clinical practice were formulated based on the expert opinion of the Working Group, while taking into consideration the published data and results of the survey on uptake in clinical practice. The draft document was then opened for online peer review to ESHRE members and revised in light of the comments received.

Main results and the role of chance
RIF describes the scenario in which the transfer of embryos considered to be viable has failed to result in a positive pregnancy test sufficiently often in a specific patient to warrant consideration of further investigations and/or interventions. The recommended threshold for the cumulative predicted chance of implantation to identify RIF for the purposes of initiating further investigation is 60%. When a couple have not had a successful implantation by a certain number of embryo transfers and the cumulative predicted chance of implantation associated with that number is greater than 60%, then they should be counselled on further investigation and/or treatment options. This term defines clinical RIF for which further actions should be considered. Nineteen recommendations were formulated on investigations when RIF is suspected, and 13 on interventions.

Limitations, reason for caution
While awaiting the results of further studies and trials, the ESHRE Working group recommends identifying of RIF based on the chance of successful implantation for the individual patient or couple and to restrict investigations and treatments to those supported by a clear rationale and data indicating their likely benefit.

Wider implications of the findings
This paper provides good practice advise, but also highlights the investigations and interventions that need further research. This research, when well-conducted, will be key to making progress in the clinical management of RIF.

Study funding and competing interest(s)
Yes.
The other authors had nothing to disclose.