Comparison of clinical effects between early follicular prolonged GnRH agonist protocol and GnRH antagonist protocol in 3310 cycles: a retrospective study

BACKGROUND: It is the duty of doctors to choose a safe, simple, economic and effective controlled ovulation stimulation (COS) protocol for the patients. This study aims to compare the clinical effects of the early follicular prolonged GnRH agonist (EFPL) and GnRH antagonist (GnRH-Ant) protocols, hoping to provide some reference for clinicians when choosing COS program. METHODS: A retrospective study included 3310 ovum pick up cycles undergoing assisted reproductive technology during January 2019 to May 2022 in Renmin Hospital of Wuhan University. Propensity Score Matching (PSM) and multivariable logistic regression analysis were used to improve the comparability between the two protocols. Subgroups were divided according to age, body mass index (BMI) and anti-Mullerian hormone (AMH). The live birth rate (LBR) and clinical pregnancy rate (CPR) were the primary outcomes. RESULTS: After PSM, the endometrial thickness, fresh embryo transplantation rate, chemical pregnancy rate, CPR were significantly higher in EFPL group than that in GnRH-Ant group (P < 0.001). The E2, LH, P values on trigger day were significantly lower in EFPL group (P < 0.001). The cycle cancellation rate was significantly reduced in EFPL group (P < 0.001). However, the total amount of Gn and duration of Gn were significantly increased in the EFPL group (P < 0.001). Multivariable logistic regression analysis showed that the LBR was significantly higher in EFPL group after matching [OR (95%CI), 1.86 (1.13, 3.05), P = 0.02], especially for those with age < 35 years [OR (95%CI), 1.95 (1.14, 3.34), P = 0.02], BMI < 24 kg/m(2) [OR (95%CI), 2.08 (1.14, 3.80), P = 0.02], AMH levels ≥ 4.5 ng/ml [OR (95%CI), 4.19 (1.53, 11.43), P < 0.01]. CONCLUSION: EFPL regimen is more suitable to elicit live birth for those young patients with BMI < 24 kg/m(2) and AMH ≥ 4.5 ng/ml. However, for patients with decreased ovarian reserve or advanced age, EFPL regimen has no advantage over the GnRH-Ant regimen.