P-446 Personalization of the euploid embryo transfer guided by the endometrial receptivity analysis in patients with &gt;1 previous failed transfer
Authors: Valbuena Perilla D , Gómez C , Stankewicz T , Castellón J  A , Al Asmar N , Simón C , Rubio C , Ruiz M 
Published: July 2024

Abstract

Study question
Does personalized embryo transfer (pET) guided by Endometrial Receptivity Analysis (ERA) increase reproductive outcome in patients with &gt;1 previous failed transfer of an euploid embryo?

Summary answer
pET guided by ERA resulted in a significantly higher Pregnancy Rate (PR), Ongoing Pregnancy Rate (OGPR) and Live Birth Rate (LBR) versus standard embryo transfer.

What is known already
pET consists of synchronizing embryo transfer with the optimal endometrial receptivity status by the transcriptomics identification of the personalized window of implantation (WOI). Euploid transfers improve reproductive outcome controlling the embryo contribution in the implantation. Controversial results have been published regarding the clinical usefulness of pET in a range of clinical indications. Here we present data from patients with &gt;1 previous failed embryo transfer (ET) in a subsequent euploid ET.

Study design, size, duration
Multicenter retrospective study involving 270 patients with at least one previous implantation failure between 2017 and 2021. These patients were divided into two groups according to their subsequent transfer: study group (pET guided by ERA) (n = 200), and control group (standard transfer) (n = 70). All the ET were done in Hormone Replacement Therapy cycles (HRT). PR, OGPR and LBR were compared between the two groups.

Participants/materials, setting, methods
Age, body mass index, previous failed attempts, inner cell mass (ICM) and trophectoderm (TE) quality of the transferred embryos were compared between the groups. Study group had an ERA result as standard WOI or displaced WOI and pET of an euploid embryo was carried out in a subsequent HRT cycle (following the same conditions and recommendations provided by ERA). Wilcoxon rank sum test was applied to quantitative comparations. Chi-square test was done for categorical variables.

Main results and the role of chance
Clinical results in terms of PR, OGPR and LBR were significantly higher when pET guided by ERA was performed when compared to the non-ERA group. PR was 65% (130/200) in pET versus 37.14% (26/70) in control group (P = 0.000088); OGPR was 49% (98/200) in pET versus 27.14% (19/70) in control group (P = 0.0024); and LBR was 48.20% (95/197) in pET versus 26.09% (18/69) in control group (P = 0.0022). Control and demographics variables did not show differences between the two groups: Age: 35.27 ± 3.86 versus 35.77 ± 3.35 (P = 0.31); BMI: 22.99 ± 3.02 versus 23.25 ± 3.72 (P = 0.52); Previous failed attempts: 2.42 ±1.78 versus 2.17 ±1.81 (P = 0.32); P values where 0.1 and 0.36 for comparisons of optimal quality of ICM and TE, respectively.

Limitations, reasons for caution
This is a retrospective study, having the limitations of its nature.

Wider implications of the findings
These results show that pET guided by the ERA test of an euploid embryo significantly increases the reproductive outcomes (PR, OGPR and LBR) in patients with ≥1 previous failed transfer compared to the standard frozen ET.

Trial registration number
Hospital Clínico de Valencia Ethic Committee approval nº. 2021/018.