P-634 Is duo stim a better approach than non-consecutive cycles in patients undergoing PGTA?
Authors: Cerrillo M , García J , Kohls G , Lopez C , Mayoral M , Garcia-Velasco J A 
Published: June 2023

Abstract

Study question
Are there differences in the results of cycles and in the time to achieve an euploid embryo in cycles with DuoStim compared to non-consecutive cycles?

Summary answer
A DuoStim strategy does not compromise ovarian response, oocyte competence or euploidy rate, and reduces time to pregnancy.

What is known already
In patients with advanced maternal age undergoing PGT-A, the risk of not reaching embryo transfer is relatively high. Increasing the number of oocytes available should increase the chances of finding a healthy euploid embryo and reach embryo transfer. Recently, DuoStim has been proposed as an alternative to accumulate oocytes prior to the final cycle in which oocytes will be fertilized, cultured, and biopsied Duostim strategy allows to reduce the time between ovarian stimulations, which may reduce the stress that waiting for assisted reproduction treatments entails for patients

Study design, size, duration
Retrospective study carried out at our institution during 2015-2020 with 451 patients &gt; 38 years undergoing PGT-A and whose previous cycles were distributed as follows: n = 101 performed DuoStim (first OS with oocyte vitrification, second was reinitiating OS five days after OPU) and a control group of 350 patients who underwent two standard non-consecutive cycles, the first to accumulate oocytes and from the second cycle, and then performed PGT-A with all oocytes, fresh and vitrified.

Participants/materials, setting, methods
All patients undergoing PGT-A performed 1 or 2 ovarian stimulations (OS) cycles to accumulate oocytes. OS cycles were re-initiated after a 5-day interval. Trophectoderm biopsies were studied by NGS. The variables were expressed as mean ± SD and comparison among groups by using ANOVA.

Main results and the role of chance
Mean age was comparable in both groups, DuoStim vs control 39.3±3.1 vs 39.2±3.0; p:0.76
AMH was lower in DuoStim group compared with control group (1.07±0.56 vs 2.64±4.1 ng/mL; p:0.006, and AFC were 4.3±2 vs 7.1±3; p:0.013 respectively.
Gonadotropin doses were higher in DuoStim group compared control group 4576.8±1847 vs 4045±1857 IU; p:0.01, and total stimulation days were significantly higher in DuoStim compared with control group (22.7±4.85 vs 18.5±10,74; p &lt; 0.001.
The mean of total eggs retrieved in both OS were similar between DuoStim and control group (12.9 vs 13.1; p = 0.78)
The ratio of euploid embryos found was similar 35.99 % vs 38.6%
When we compared pregnancy rates per embryo transfer, were similar between both groups 66.6% (36/54) vs 65.3% (132/211); p value=0.98.
We confirmed differences in the time to achieve the first euploid embryo in favour of DuoStim group 30.2±6 vs 36±9 with a p value: 0.001.

Limitations, reasons for caution
The retrospective nature is the major limitation of this study. The study population reflects the indication of PGT-A in a particular setting, mainly advanced maternal age and in DuoStim group a poor prognosis profile

Wider implications of the findings
Accumulating oocytes through vitrification prior to PGT-A with DuoStim offers similar clinical outcomes in both groups, it may reduce time to reach an euploid embryo, which is relevant for advanced maternal age group of patients.

Trial registration number
Not applicable