Semi-automated versus manual embryo vitrification: inter-operator variability, time-saving, and clinical outcomes

Area of Science:

• Reproductive Medicine
• Embryology
• Cryobiology

Background:

• Vitrification is a key technique in assisted reproductive technology for embryo cryopreservation.
• Comparing manual vitrification (MV) with semi-automated vitrification (AV) is crucial for optimizing laboratory protocols.

Purpose of the Study:

• To evaluate if semi-automated vitrification (AV) reduces inter-operator variability and improves clinical outcomes compared to manual vitrification (MV).

Main Methods:

• Retrospective analysis of 282 patients undergoing embryo cryopreservation using either MV (Irvine®-CBS®) or AV (GAVI®) between November 2017 and September 2020.
• Inter-operator variability was assessed by comparing intact and positive embryo survival rates among 5 operators.
• Vitrification time was compared between the two methods.

Main Results:

• Manual vitrification (MV) resulted in a higher positive survival rate (96%) compared to semi-automated vitrification (AV) (90%) (p < 0.05).
• Intact survival rates (86% vs. 84%) and clinical pregnancy rates (27% vs. 22%) were not significantly different between MV and AV.
• No significant inter-operator variability was observed for either method; MV was more time-efficient (11 ± 9 min faster).

Conclusions:

• Manual vitrification (MV) offers superior total embryo survival rates and is more time-efficient than semi-automated vitrification (AV).
• Both MV and AV techniques exhibit low operator variability, ensuring consistent cryopreservation results.