Optimal Timing for Oocyte Denudation and Intracytoplasmic Sperm Injection

Abstract

Objectives. To analyze the impact of oocyte denudation and microinjection timings on intracytoplasmic sperm injection (ICSI) outcomes. Study Design. We included ICSI cycles with the following parameters: rank 1 or 2, female age <36 years, male factor infertility, long protocol using GnRH agonist and rFSH for ovarian stimulation, and use of freshly ejaculated sperm (n = 110). Several ICSI parameters were analyzed according to the time between oocyte retrieval and denudation (T 1) and the time between denudation and ICSI (T 2) using a statistical logistic regression analysis. Results. Neither T 1 nor T 2 had a significant influence on the Metaphase II (MII) rate but the fertilisation rate (FR) showed a significant improvement when T 1 was longer (optimal results at T 1 = 3 hours) while FR significantly decreased with the increase of T 2. Optimal implantation (IR) and pregnancy (PR) rates were obtained when T 1 was around 2 hours. Conclusion. Incubation of oocytes around 2 hours between retrieval and denudation may not increase MII rate but appears to lead to the optimal combination of FR and IR.

Performing ICSI within 4 hours after denudation optimizes clinical outcomes in ICSI cycles

“…Our present study discovered DN-ICSI time interval acted as an independent predictor for clinical outcomes in ICSI cycles. Indeed, most investigators have showed the relation between DN-ICSI interval and fertilization rate [6,11,14,15]. Nevertheless, there are limited studies available for the influence on the clinical outcomes associated with raised DN-ICSI interval.…”

“…It was believed that the procedure might achieve a better outcome if ICSI was performed immediately after denudation. Besides, Catherme patrat et al [6] performed logistic regression analysis on 110 cycles and found that in terms of the fertilization rate, an optimal time to carry out DN was within 3 h following OPU and performing ICSI soon after DN was a good choice. However, other researches did not confirm the optimal time to perform ICSI following DN.…”

“…However, Catherme patrat et al [6] reported the time between denudation and ICSI was negatively correlated with fertilization rate. With the prolongation of time interval between denudation and ICSI, the fertilization rate gradually decreased.…”

Science of cryopreservation in reproductive medicine – Embryos and oocytes as exemplars

“…Mature oocytes are at the stage of the second meiotic division (M II), which is sensitive to physical and chemical influences in cryopreservation. The release of oocytes from surrounding cumulus cells and granulosa (denudation) improves the oocyte survival rate [24].…”

The gene expression profile of cumulus cells reveals altered pathways in patients with endometriosis

“…After oocyte pick up, every oocyte surrounded by its own CC was cultured individually in 30 μl microdrops of culture media (ISM1, Origio) under mineral oil (Liquid Paraffin, Origio) for at least two hours [22]. Decoronization was carried out by placing each cumulus oocyte complex (COC) in separated drops of recombinant human hyaluronidase (ICSI cumulase, Origio) under oil.…”