P-657 Administration of an extra Gonadotropin dose on trigger day in patients undergoing elective egg freezing
Authors: Herzberg S , Etzyoni A , Karavani G , Simon A , Ben-Meir A , Imbar T 
Published: June 2022

Abstract

Study question
Does an extra Gonadotropin (GT) dose on trigger day during a gonadotropin-releasing hormone (GnRH) antagonist cycle for oocyte cryopreservation result in improved cycle outcomes?

Summary answer
An extra GT dose on trigger day in patients undergoing elective egg freezing is not associated with increased oocyte yield.

What is known already
The most common controlled ovarian hyperstimulation (COHS) protocol used in elective oocyte cryopreservation cycles is a GnRH antagonist protocol with a GnRH agonist trigger. There is no consensus about the timing of the final gonadotropin dose administration. Some physicians add an extra GT dose during the ovulation trigger day and others advise to receive the last GT dose the day before. The yield of this extra GT dose was not previously evaluated.

Study design, size, duration
A retrospective cohort study, consisting of cycles of elective oocyte cryopreservation at Hadassah Medical Center from 1.2017 through 5.2021. Patients were divided into 2 groups- women who received their last GT dose a day before the GnRH agonist trigger, and women who received the last GT on the trigger day. Background and gynecologic characteristics, as well as COHS cycle parameters, were compared. The primary outcome was the average number of mature oocytes in each group.

Participants/materials, setting, methods
Women 30-41 years who were admitted for elective oocyte cryopreservation. Women who were referred due to medical reasons or cycles with a protocol other than GnRH antagonist were excluded. Ovarian stimulation with GT began on the 3rd day of the cycle, and five days later, a GnRH antagonist was added. When more than two mature follicles were demonstrated, a GnRH agonist trigger was administrated and approximately 36 hours later, the oocyte aspiration procedure was performed

Main results and the role of chance
During the study period, 448 elective egg freezing cycles were performed, 151 cycles with an extra dose on the trigger day and 297 cycles without an extra GT dose. The groups did not differ in their background characteristics, age, BMI, GT used, and the number of induction days. However, the extra GT group had significantly higher day 3 follicular stimulating hormone (FSH), lower anti-Mullerian hormone (AMH), and lower maximal Estradiol (E2) levels. The extra GT dose group had a significantly lower mean number of mature oocytes (11.1±7.1 vs. 6.4±4.5, p &lt; 0.001).
To adjust for the maximal E2 parameter, that differed between the groups, an additional analysis was performed, dividing the two groups into subgroups of cycles with maximal E2 above and below 10,000 pmol\l. Interestingly, even in cycles with maximal E2 above 10,000 pmol\l, the extra dose group had poorer results (10.3±4.3 vs. 12.7±7.2, p &lt; 0.001). This difference was also noted in cycles with E2 below 10,000 pmol\l (5.4±4.0 vs 8.7±6.1 mature oocytes, p = 0.011). Additionally, a multiple regression model for the prediction of several oocytes retrieved showed that the extra GT dose parameter was not associated with increased oocytes number.

Limitations, reasons for caution
The retrospective design of this study and the differences in cycle characteristics between patients that did or did not receive an extra GT dose on trigger day make it prone to selection bias.

Wider implications of the findings
Our study shows that administration of an extra GT dose on trigger day in oocyte cryopreservation cycles does not yields more mature oocytes. However, wider prospective studies are needed to thoroughly investigate the implications of this treatment’s effect on cycle outcomes.

Trial registration number
Not applicable