Analysis of influencing factors on the rate of high-quality embryos induced by rectangular plan during in vitro fertilization.

Objective: To explore factors influencing high-quality embryo rate in long protocols for controlled ovarian hyperstimulation (COH) during in vitro fertilization (IVF).

Methods: It was a retrospective case-control study including patients receiving assisted pregnancy treatment at the Reproductive Medicine Department of the Maternal & Child Care Center of Qinhuangdao from January 2018 to October 2023. This study adopted 724 treatment cycles using COH involving intermediate-acting and long-acting protocols. According to the high-quality embryo rate on D3, the enrolled patients were divided into Group-A for control (high-quality embryo rate ≥40%, n=297) and Group-B without high-quality embryo (excellent embryo rate=0, n=427). Factors with P<0.05 in the univariate analysis were incorporated into the Logistic regression model for binary logistic regression analysis.

Results: There were no statistically significant differences in male age, years of infertility, body mass index (BMI), baseline follicle-stimulating hormone (FSH) levels, AMH, total gonadotropin (Gn)dose, total days of Gn administration, sperm concentration, motility, normal morphology rate, and LH levels on the day of human chorionic gonadotropin (hCG) injection between Group-A and Group-B (all p>0.05). In addition, the Logistic binary regression analysis showed that in the cycle without high-quality embryos on D3, elevated progesterone on the day of hCG injection was an independent risk factor affecting the developmental potential of late-stage embryos.

Conclusion: For cycles with poor embryo quality, the increase in progesterone levels in the late stage of COH has a significant negative impact on the formation of effective blastocysts.