Perivitelline Space Abnormalities as Predictors of Fertilization and Embryo Quality in Intracytoplasmic Sperm Injection (ICSI) Cycles: A Prospective Observational Study.
PVS abnormalities are associated with poorer embryo quality in ICSI cycles, but the clinical implications for pregnancy outcomes remain unclear.
Where it sits
this study against the rest of the hmg (human menopausal gonadotropin) corpusSummary and findings
This study evaluated the association of perivitelline space (PVS) abnormalities with fertilization rates and embryo quality in 96 intracytoplasmic sperm injection (ICSI) cycles involving 631 metaphase II (MII) oocytes. The findings indicated that fertilization rates were highest in normal PVS oocytes at 85.4% and lowest in PVS-L oocytes at 74.5%, with significant differences in embryo quality based on PVS morphology. No clinical outcomes such as pregnancy or live birth were assessed.
Abstract
Background Oocyte morphology is an important non-invasive indicator of developmental competence in assisted reproductive technology (ART). Among extra-cytoplasmic features, perivitelline space (PVS) abnormalities have shown inconsistent associations with fertilization and embryo quality after intracytoplasmic sperm injection (ICSI). This prospective observational study evaluated the association of PVS abnormalities with fertilization rates and embryo quality in ICSI cycles. Methodology Ninety-six ICSI cycles comprising 631 metaphase II (MII) oocytes were included. Oocytes were classified into four groups based on PVS morphology: normal PVS, large PVS (PVS-L), granular PVS (PVS-G), and combined PVS-L with PVS-G. Fertilization rates and day 3 embryo quality, graded according to the Istanbul Consensus criteria, were compared across groups using the chi-square test. Odds ratios (ORs) were calculated to assess the association with poor-quality embryos. Results Fertilization rates were highest in normal PVS oocytes (147/172, 85.4%) and lowest in PVS-L oocytes (132/177, 74.5%), although differences were not statistically significant (p = 0.082). Embryo quality was significantly associated with PVS morphology. Grade I embryos were most frequent in the normal PVS group (88/147, 59.9%) and least frequent in the combined PVS-L + PVS-G group (15/89, 17.1%) (p < 0.001). Oocytes with combined PVS abnormalities had a markedly higher risk of producing poor-quality embryos (74/89, 83.1%) compared with normal PVS oocytes (59/147, 40.1%). Conclusion PVS abnormalities, particularly when multiple abnormalities coexist, are associated with significantly poorer embryo quality in ICSI cycles. Assessment of PVS morphology may provide a valuable non-invasive adjunct for evaluating oocyte competence, although clinical outcomes such as pregnancy and live birth were not assessed in this study.
Background
The study addresses the clinical question of how perivitelline space abnormalities may predict fertilization and embryo quality during ICSI cycles. Previous research has indicated that embryo quality is crucial for successful outcomes in assisted reproductive technologies, but the specific role of perivitelline space abnormalities has not been thoroughly explored. This study aims to fill that gap by providing observational data on this relationship.
Methods
This is a prospective observational study involving patients undergoing ICSI cycles. The sample size and specific dosing information for HMG are not reported. The primary outcome measures include fertilization rates and embryo quality assessments, but further details on the duration and specific methodologies are not provided.
Results
Not reported in abstract.
Interpretation
Without specific numeric results or effect sizes reported, it is difficult to compare these findings to prior literature or assess the clinical significance of any observed relationships. The lack of detailed results limits the ability to draw strong conclusions about the implications for practice. Potential confounds include the observational nature of the study, which may introduce biases.
Key findings
- Not reported in abstract.
Limitations
- Not reported in abstract.