Does Blastocyst-To-Oocyte Ratio Predict Live Birth When Only One Blastocyst Is Available For Transfer?

Area of Science:

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

Background:

• Oocyte retrieval numbers and subsequent blastocyst development are crucial in IVF.
• The blastocyst-to-oocyte ratio is often considered an indicator of ovarian response and embryo quality.
• Understanding factors influencing live birth rate (LBR) is essential for optimizing IVF outcomes.

Purpose of the Study:

• To evaluate if the blastocyst-to-oocyte ratio affects live birth rate (LBR) in cycles with a single blastocyst transfer.
• To identify the primary predictors of LBR in single blastocyst frozen embryo transfer (FET) cycles.

Main Methods:

• A retrospective cohort study of 2,125 single blastocyst frozen embryo transfer (FET) cycles.
• Patients were stratified by blastocyst-to-oocyte ratio quartiles.
• Logistic regression analysis was used to determine predictors of LBR, including female age, embryo quality, and BMI.

Main Results:

• The blastocyst-to-oocyte ratio did not show a significant association with LBR.
• Female age and embryo quality were identified as independent predictors of LBR.
• Younger age and higher AMH levels were observed in the lowest quartile of blastocyst-to-oocyte ratio.

Conclusions:

• The blastocyst-to-oocyte ratio is not a significant determinant of LBR in single blastocyst transfer cycles.
• Female age and embryo quality are the most critical factors influencing successful live birth.
• Embryo selection is paramount, rather than solely relying on ovarian response metrics, for optimizing IVF outcomes.