P-495 What is the optimal cut off value of the number of egg donations from the same egg donor lifetime?
Authors: Aydin B , Dorofeyeva U , Oleksandra K , Khrystyna M , Gudkova D , Lytvyn B , Vozniuk V , Karimova H , Yetim I , Kotlyarova O 
Published: June 2023

Abstract

Study question
Do repeated ovarian stimulation cycles in the same donor have a negative impact on clinical outcome?

Summary answer
There is no negative impact of the consecutive ovarian stimulation cycles on embryological parameters and outcomes from the same donor.

What is known already
Different country regulations required from single stimulation to maximum 6 stimulations for egg donors in lifetime. Modern assisted reproductive technologies (ART) clinics should consider this issue described above from the point of view of the number of oocytes retrieved during controlled ovarian stimulation cycles - this is a balance between efficacy of the ART in infertility treatment programs and donor safety. Despite some studies have underscored the likely negative impact of repeated cycles on outcomes it remains up for debate. The age groups of 20-30 years old egg donors may give similar clinical outcomes for 1st-6th attempt of stimulation cycles.

Study design, size, duration
In this single center, 4 years of retrospective study included oocyte donors (n = 96) with repeating cycles of ovarian stimulation (COS). Cycles took place between January 2018 and December 2022 in an IVF clinic with respect to at least 6 months interim between each cycle.
We evaluated the concordance between the follicle-to-oocyte index (FOI), number of oocytes retrieved, maturation rate (MR), utilization rate (UR) and the numbers of attempts from 1st to 6th.

Participants/materials, setting, methods
The mean age of the patients in this study was represented in dynamics (SD) from 1st COS program 23,2 (3,2) to 27,8 (3,7) years during the final 6th cycle, all of them passed through 6 consequence COS programs.. The association between each COS cycle' parameters and the differences in COS output was assessed by T-Student (parametric) or U-Mann-Whitney (non-parametric).

Main results and the role of chance
We observed that mean number (SD) of mature oocytes retrieved was non significantly different and raised from the 1st attempt –18,46 (8,89), to 5th - 22,03 (10,16), with decreasing during 6th COS – 21,55 (12,06). MR and UR indicators had a fluctuating picture of the dynamics of values. They either increased or decreased from one cycle to another. Mean values of MR was the lowest after 3rd COS (81%) and the highest – 4th COS (84%). UR dynamic was similar with lowest value after 1st cycle (12,0%) and the maximum 17,9% after 6th COS program. FOI parameter was measured within values of 73,82 – 81,02: min value 73,82 (16,40) was observed after the second stimulation cycle and max value – after fifth (mean = 81,02±18,26). These changes were found to be not significantly different (p &gt; 0.05). Regarding egg donation cycle outcome for recipients (age average 34,57) attempt 1st −3rd gave 96,14% fertilization rate, 66,89% used blastocysts rate and 60,77% clinical pregnancy rate. Recipients ( average age 33,19) attempting 4th- 6th gave 94.17% fertilization rate, 64,09% used blastocysts rate and 63,19% clinical pregnancy rate.

Limitations, reasons for caution
This study is limited regarding retrospective nature and by the small samples size. Expanding the number of participants is the possible next step, in order to challenge or rather confirm our preliminary findings.

Wider implications of the findings
The controversial dynamic of the changes of the embryological parameters and COS outcomes in the same donor’s pool after repeated stimulation cycles with no statistically observed differences can be grounds for making a positive decision both personally by the donor and the IVF specialist.

Trial registration number
NA