P-278 What are the effects of ICSI procedure time intervals on in vitro fertilization outcomes?
Authors: Merdassi Akkari G , Chabchoub I , Mhamdi Z , Ben rhouma K , Triki O , Bahri H 
Published: June 2023

Study question

Do time intervals between oocyte pick-up (OPU), oocyte denudation (OD), and Intra-cytoplasmic Sperm Injection (ICSI) impact ICSI outcomes?

Summary answer

ICSI time intervals impact oocyte maturation, blastulation and pregnancy rates. There is no effect on fertilization and cleavage rates.

What is known already

Cytoplasmic and nuclear oocyte maturation are crucial for the success of in vitro fertilization and embryo development. Cumulus cells enhance oocyte maturation. Therefore, prolonged oocyte culture prior to denudation may induce oocyte apoptosis. There is no consensus for optimal time intervals between different ICSI procedures and their effects on fertilization, embryo and blastocyst, development and pregnancy rates.

Study design, size, duration

A retrospective analysis of 794 ICSI fresh cycles was performed at the Alyssa Fertility Group Center, between Juin 2021 and December 2022.

Participants/materials, setting, methods

ICSI cycles were performed on women aged ≤40 years, with at least 3 mature oocytes. Semen partner concentrations greater than 1million/mL were included. Time intervals between OPU, OD, and ICSI were recorded. We evaluate the effects of these timing intervals on oocyte maturation, fertilization, embryo development and pregnancy rates.

Statistical analysis was performed using SPSS 22.0. Kolmogorov–Smirnov, Student t, Pearson tests, and ROC curve analysis were used. Level of signification p-value &lt;0.05.

Main results and the role of chance

The mean women’s age was 33,2 years (SD 4,4). Mean times in hours for OPU/OD, OD/ICSI, and OPU/ ICSI were respectively: 01:28(SD 00:37); 02:35(SD 01:01); 04:03(SD 01:08). Positive correlations were seen between maturation rate and OPU/OD; OPU/ICSI intervals respectively (r = 0,217, p = 0,002; r = 0,193, p = 0,005).There were no significant correlation between ICSI time intervals, fertilization and cleavage rates. Top quality embryos rates were positively associated with OPU/OD time interval (r = 0,136: p = 0,049). The blastulation rate was positively associated with OPU/OD, OD/ICSI, and OPU/ICSI time intervals respectively(r = 0,183: p = 0,008; r = 0,211: p = 0,002; r = 0,279: p &lt; 0,001).Pregnancy rates were positively correlated to OD/ICSI and OPU/ICSI respectively: (r = 0,158: p = 0,022; r = 0,188: p = 0,006).

The ROC curves analysis revealed that the cut off value of time intervals between: OPU/OD was 01:10 (AUC = 0,554; IC 95% 0,476-0,632), p = 0,185; OD/ICSI was 02:20 (AUC = 0,600; IC 95% 0,516-0,669), p = 0,023 and for OPU/ICSI: 03:50, (AUC = 0,600; IC 95% 0,524-0,676), p = 0,014.

Limitations, reasons for caution

Trigger time is an important factor for oocyte maturation that should be noted. This study is limited by its retrospective nature. Potential unmeasured confounding factor cannot be excluded

Wider implications of the findings

Time intervals between all the ICSI procedures affect reproductive outcomes. According to our findings, excessive oocyte incubation time before denudation should be avoided. ICSI should be performed 2 hours after OD. Time intervals should be adjusted according to laboratory practice to improve ICSI outcomes.

Trial registration number

Not applicable