P-750 Is maximalization of the ovum pick-up (OPU) procedure beneficial for the outcome of assisted reproductive technology (ART) cycles?
Authors: Danieli-Gruber S , Sapir O , Netaneli D , Hochberg A , Ben-haroush A , Wertheimer A , Altman E , Shochat T , Shufaro Y 
Published: July 2024

Abstract

Study question
Is aspiration of more oocytes than the antral follicle count (AFC) beneficial for the current (pregnancy/live birth rates) and future products of an ART cycle?

Summary answer
Aspirating more oocytes than the AFC does not influence the outcome of the fresh cycle but is beneficial for fertility preservation and cumulative pregnancy rates.

What is known already
AFC is a reliable and immediate indicator for ovarian reserve assessment and is in correlation with the ovarian response to gonadotropin stimulation. Additionally, correlation between AFC and embryo quality, clinical pregnancy and live birth rates was reported. There is no data concerning the impact of the ratio between the AFC and actual number of oocytes retrieved on cycle outcome.

Study design, size, duration
Data of the first oocyte aspiration for ICSI performed between 2018-2022 in attempt to conceive (ICSI, n = 399) or for planned oocyte vitrification (fertility preservation FP, n = 283) was retrieved. Each group was divided into two subgroups according to their ‘oocyte/AFC index’ (OAFCI): &lt;1 and ≥1.
The stimulation parameters, number of aspirated oocytes, their maturity rate, number of cryopreserved oocytes/embryos, clinical pregnancy (CPR) and live birth rates (LBR) were compared between the subgroups.

Participants/materials, setting, methods
The AFC was determined by professional sonographers using a 9 MHz transvaginal ultrasound probe. The most adjacent measurement to the stimulation initiation was used. Stimulation protocol and FSH dose were determined according to the AFC and individual clinical consideration. Patients not in their first cycle, natural cycle aspirations, and cases in which no oocytes were retrieved, were excluded.

Main results and the role of chance
OAFC≥1 was associated with higher pre-trigger estradiol (6159 pmol/L vs. 4304, p &lt; 0.001 for ICSI, 4949 vs. 3488, p &lt; 0.001 for FP), and longer duration of simulation (9.8 days vs. 9, p &lt; 0.001 for both FP and ICSI). More oocytes were aspirated in OAFC≥1 groups in both FP (16.9±11.2 vs. 7.9±5.9, p &lt; 0.001) and ICSI (17.4±9.8 vs. 10.7±6.7, p &lt; 0.001). Oocyte maturity was unaffected by the OAFCI in the ICSI group, but was lower in FP group at OAFC≥1 (0.79 vs.0.84 p = 0.005).
OAFCI≥1 was associated with a higher number of cryopreserved embryos (3.9 vs. 2.3, p &lt; 0.001 for ICSI) and a higher number of vitrified oocytes (13.4 vs. 6.4 p &lt; 0.001 for FP).
The OAFCI had no impact on CPR (39% vs. 60%, p = 0.27) and LBR (19.9% vs. 24.8%, p = 0.33).
On multivariate analysis controlling for age, gonadotropin dosage and duration of stimulation, OAFC≥1 was associated with a higher number of cryopreserved embryos (ICSI group aOR 1.2, 95% CI 1.1-1.3, p &lt; 0.001), and vitrified oocytes (aOR 1.2, 95% CI 1.1-1.2, p &lt; 0.001) and lower maturity index (aOR 0.1, 95% CI 0.03-0.51, p &lt; 0.001) in the FP group.

Limitations, reasons for caution
Retrospective study analyzing results of treatment cycles without an intention to aspirate differently.

Wider implications of the findings
Aspiration of a more oocytes than the current AFC was not associated with higher CPR or LBR in the fresh cycle, but harbors the possibility to cryopreserve more oocytes and embryos. This might translate into higher cumulative pregnancy rates later on.

Trial registration number
Not applicable