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Updated: Sep 14, 2025
Human Egg Maturity Assessment and Its Clinical Application
Published on: August 19, 2019
Enhancing embryo quality through meiotic spindle-aligned microinjection in POSEIDON group 4 patients undergoing
Li-Te Lin1, Pei-Fen Liao2, Chia-Jung Li3
1Department of Obstetrics and Gynecology, Kaohsiung Veterans General Hospital, Kaohsiung City, Taiwan; Department of Pharmacy and Master Program, College of Pharmacy and Health Care, Tajen University, Pingtung County, Taiwan; Institute of Biopharmaceutical Sciences, National Sun Yat-sen University, Kaohsiung City, Taiwan; Department of Biological Science, National Sun Yat-sen University, Kaohsiung City, Taiwan; Institute of Medicine, Chung Shan Medical University, Taichung City, Taiwan; School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung City, Taiwan.
Background:
Embryologists traditionally use polar body (PB) positioning to guide intracytoplasmic sperm injection (ICSI). However, PB location cannot accurately predict meiotic spindle (MS) position. Polarized light microscopy enables noninvasive MS visualization during ICSI. We assessed whether MS-aligned ICSI improves embryo quality compared to conventional PB alignment in POSEIDON group 4 patients.
Methods:
This retrospective cohort study included 315 women meeting POSEIDON Group 4 criteria undergoing IVF-ICSI cycles. The study group comprised 168 women with MS-aligned microinjection, while 147 controls underwent PB-aligned procedures. We compared baseline characteristics, cycle parameters, and embryo quality between groups.
Results:
The MS-aligned group was older with more previous IVF attempts than the PB-aligned group. The MS-aligned group demonstrated significantly higher fertilization rates, cleavage rates, and top-quality day 3 embryo (TQE) rates. Multivariate analysis revealed that MS alignment increased the likelihood of achieving ≥1 TQE (odds ratio [OR] 4.22, 95 % confidence interval [CI] 2.24-7.96, P < 0.001) and TQE rate ≥50 % (OR 3.63, 95 % CI 2.06-6.39, P < 0.001).
Conclusions:
MS-aligned microinjection may enhance embryo quality in older patients with diminished ovarian reserve undergoing IVF-ICSI cycles.
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