Revisiting the progesterone to oocyte ratio

Area of Science:

• Reproductive Medicine
• Biostatistics
• Infertility Research

Background:

• Predicting live birth in assisted reproductive technology (ART) is crucial for optimizing treatment outcomes.
• The P to oocyte (P/O) ratio has been proposed as a potential predictor, but its independent utility requires critical evaluation.

Purpose of the Study:

• To critically evaluate the predictive value of the P to oocyte (P/O) ratio for live birth in ART cycles.
• To determine if the P/O ratio offers incremental predictive improvement over the number of oocytes (O) and embryos (P) alone.

Main Methods:

• Retrospective cohort study of 7,608 fresh autologous ART embryo transfer (ET) cycles.
• Generalized estimating equation (GEE) models were used to assess the association of P, O, and P/O ratio with live birth.
• Receiver operating characteristic (ROC) curves were employed to evaluate the predictive performance of these variables.

Main Results:

• Both the number of embryos (P) and oocytes (O) were individually associated with live birth in univariate analyses.
• In multivariate models, only the number of embryos (P) remained significantly associated with live birth; the P/O ratio did not show independent predictive value.
• ROC curve analysis indicated that the P/O ratio provided no incremental improvement in predicting live birth compared to P or O alone.

Conclusions:

• While the number of embryos (P) and oocytes (O) are useful predictors of live birth in ART, the P/O ratio does not enhance predictive accuracy.
• The number of oocytes does not mitigate the negative association of a high embryo count with live birth outcomes.
• Clinical decision-making regarding ART outcomes should rely on the independent predictive values of embryo and oocyte numbers rather than their ratio.