Prediction of human blastocyst development from morulas with delayed and/or incomplete compaction

Area of Science:

• Embryology
• Reproductive Medicine
• In Vitro Fertilization (IVF)

Background:

• Morula compaction and fragmentation are critical indicators of early embryo development.
• Understanding these factors is crucial for optimizing IVF success rates.

Purpose of the Study:

• To investigate the impact of delayed morula compaction and fragmentation on subsequent blastocyst development.
• To evaluate the predictive value of these parameters for optimal blastocyst formation.

Main Methods:

• A prospective study involving intracytoplasmic sperm injection (ICSI) cycles.
• Morulas on day 4 and day 5 were classified based on compaction and fragmentation levels using Cronus3 software.
• Key outcomes included blastocyst development rate, expansion, and optimal blastocyst quality metrics.

Main Results:

• Delayed compaction by one day was associated with reduced inner cell mass (ICM) volume.
• Increased morula fragmentation negatively correlated with blastocyst ICM size and trophectoderm cell number.
• Optimal blastocyst development rates decreased significantly with higher fragmentation grades and delayed compaction.

Conclusions:

• Compaction timing and cytoplasmic fragmentation in morulas are significant predictors of optimal blastocyst development.
• These assessments can enhance embryo selection in IVF protocols.