Objective:

To investigate the impact of gonadotropin (Gn) dose on embryo quality and pregnancy outcomes in patients undergoing controlled ovarian stimulation (COS) with antagonist regimen fertility treatment.

Approach:

• Study Design: A retrospective cohort analysis of 1854 patients treated for in vitro fertilization (IVF) between January 2019 and October 2024, categorized into four groups based on Gn dose quartiles.
• Data Analysis: Comparison of general data, embryo quality, and pregnancy outcomes among the groups, utilizing regression analysis and restricted cubic spline (RCS) curve analysis to assess relationships.

Key Findings:

• Group 1 (Gn dose ≤1,550 IU) had higher rates of excellent embryos, single blastocyst transfer, clinical pregnancy, and live births compared to groups 2, 3, and 4.
• Abortion rates were lower in group 1.
• Blastocyst formation rates were higher in groups 1 and 2 than in groups 3 and 4.
• Total Gn was identified as an independent risk factor for positive HCG rates, abortion, and live birth, and was negatively correlated with blastocyst formation rate.
• Increases in Gn above specific thresholds resulted in decreased rates of blastocyst formation, positive HCG, and live births.

Interpretation:

Gn dose influences embryo quality and pregnancy outcomes during COS, suggesting that adjusting Gn dose may improve IVF outcomes.

Limitations:

• The study is retrospective and conducted at a single center, which may limit the generalizability of the findings.
• Exclusion criteria may have introduced selection bias.

Conclusion:

Adjustment of Gn dose may improve IVF outcomes.