Cleavage vs blastocyst stage embryos: how are they interrelating?

Area of Science:

• Reproductive Medicine
• Embryology
• In Vitro Fertilization

Background:

• Cleavage-stage embryo morphology is a key factor in predicting blastocyst development.
• Understanding these predictors can optimize embryo selection for transfer.

Purpose of the Study:

• To identify variables predicting blastocyst development from cleavage-stage embryos.
• To determine if cleavage-stage morphology impacts pregnancy rates after blastocyst transfer.

Main Methods:

• Retrospective cohort study of 3072 patients and 23,124 cleavage-stage embryos.
• Analysis of blastulation rates and ongoing pregnancy rates.
• Evaluation of embryo grading and blastomere count as predictors.

Main Results:

• Higher blastulation rates correlated with better embryo grading and more blastomeres.
• Ongoing pregnancy rate was 28.9% for fresh single blastocyst transfers.
• Younger patients, higher oocyte yield, and good-quality embryo transfers were associated with higher pregnancy rates.

Conclusions:

• Embryo grading and blastomere count are significant predictors of blastocyst formation.
• Cleavage-stage embryo morphology does not impact ongoing pregnancy rates if a good-quality blastocyst is achieved.