P-612 Euploidy rates between cycles triggered with gonadotrophin-releasing hormone agonist (GnRHa), human chorionic gonadotrophin (hCG) and dual trigger
Authors: Penarrubia J , Esbert M , Garrigos V , Florensa M , Ballesteros A , Lara-Molina E 
Published: July 2024

Abstract

Study question
Is there any difference in euploidy rates between in vitro fertilization (IVF) cycles triggered with GnRHa, hCG or dual trigger?

Summary answer
There is no difference in the euploidy rate in preimplantation genetic testing for aneuploidy (PGT-A) cycles according to the trigger method used.

What is known already
The use of PGT-A has shown that the success of meiosis in the IVF laboratory is inversely correlated with maternal age. However, other uninvestigated factors involved in the IVF process may interfere with normal oocyte physiology. Since the final maturation obtained after ovarian stimulation depends on the use of drugs to promote the resumption of meiosis, it is worth investigating whether the triggering method could impact on oocyte and embryo euploidy. This study aims is to evaluate differences in embryo euploidy rates between PGT-A cycles triggered with GnRHa, hCG or dual trigger (GnRHa + hCG).

Study design, size, duration
This is a single-center retrospective study of 934 patients who underwent 1085 PGT-A cycles by Next-Generation Sequencing (NGS) from January 2017 to December 2023, using one of three possible trigger methods to induce final oocyte maturation: GnRHa, hCG, or dual trigger. The couples included in the study had normal karyotypes and no severe male factor.

Participants/materials, setting, methods
Data on the number of oocytes retrieved, ratio of metaphase II (MII) oocytes and fertilization rate, blastocyst development and embryo euploidy were assessed and compared between the GnRHa, hCG and dual trigger treatments. A secondary analysis was performed to evaluate data stratified by patient age.

Main results and the role of chance
A total of 1085 PGT-A cycles involving 934 patients (38.07 ± 3.01 years) and 2803 biopsied blastocysts were included in the analysis. Dual trigger was used in 726 (77.73%) cycles, GnRHa in 287 (26,4%) cycles and hCG in 72 (7.71%) cycles. The number of oocytes retrieved was significantly higher in the GnRHa group (GnRHa: 18.72 ± 8.59; hCG: 9.88 ± 5.64; dual trigger: 10.58 ± 5.65; p &lt; 0.001) with similar maturation rate (GnRHa: 77.46%; hCG: 74.58%; dual trigger: 76.03%; p = 0.789), fertilization rate (GnRHa: 78.12%; hCG: 76.37%; dual trigger: 79.12%; p = 0.168), blastulation rate (GnRHa: 61.03%; hCG: 58.32%; dual trigger: 58.73%; p = 0,629), high-quality blastocyst rate (GnRHa: 27,88%; hCG: 33,67%; dual trigger: 27,88%; p = 0.543) and embryo euploidy per biopsied embryo (GnRHa: 42.48%; hCG:45.49%; dual trigger:46.98%; p = 0.112). Analysis of the data stratified by age showed similar rates of euploidy rates with the three trigger methods in women younger than 41 years (&lt;35 years: GnRHa 66.50%; hCG 66.67%; dual trigger 56.97% p = 0.290; 35-37 years: GnRHa 49.45% hCG 51.04%; dual trigger 50.23%; p = 0.988; 38-40 years: GnRHa 40.93%; hCG 41.27%; dual trigger 39.13% p = 0.257). However, in patients ≥41 years old the euploidy rate was statistically higher in the GnRHa group (GnRH 31.51%; hCG 18.75%; dual trigger 16.89%; p = 0.032).

Limitations, reasons for caution
The main limitations of the study are: its retrospective design, the possibility that the trigger method was chosen based on the ovarian response and the limited number of patients in both the hCG trigger and women ≥ 41 years groups.

Wider implications of the findings
Our results suggest that triggering with GnRHa, hCG or dual trigger leads to comparable euploidy rates. Triggering with GnRHa should be recommended in older patients since it has been associated with a higher rate of embryonic euploidy.

Trial registration number
Not Applicable