Correlation between human follicular diameter and oocyte outcomes in an ICSI program

Area of Science:

• Reproductive Medicine
• Embryology
• In Vitro Fertilization

Background:

• Follicular size is a key determinant of oocyte quality and developmental potential.
• Optimizing oocyte retrieval and maturation is crucial for successful intracytoplasmic sperm injection (ICSI).

Purpose of the Study:

• To investigate the relationship between follicular diameter and oocyte recovery, fertilization, and embryo quality in ICSI cycles.
• To evaluate the impact of oocyte maturation status (mature vs. immature) on fertilization and embryo development.

Main Methods:

• Follicles (n=991) from 72 ICSI cycles were categorized by size: <10 mm (Group A), 10-14 mm (Group B), and >14 mm (Group C).
• Oocytes were classified by nuclear maturation (GV, MI, MII); immature oocytes underwent in vitro maturation (IVM).
• Fertilization rates and good quality embryo rates at Day 3 were assessed post-ICSI.

Main Results:

• Oocyte and MII oocyte recovery rates significantly increased with smaller follicles (Group A) compared to larger ones (p < 0.001).
• Fertilization and good embryo rates showed a non-significant trend of increase from Group A to Group C.
• Fertilization rates were 78% for mature and 55.3% for IVM oocytes (p < 0.001).

Conclusions:

• Retrieving oocytes from small follicles (<10 mm) and utilizing IVM for immature oocytes can enhance the overall yield of good quality embryos.
• This strategy may increase the number of transferable embryos, potentially improving ICSI success rates.