Background: The objective of this retrospective cohort study was to evaluate whether the length of pituitary blockage with gonadotrophin-releasing hormone (GnRH) antagonists or the stimulation period influence intracytoplasmic sperm injection (ICSI) outcomes in patients older than 36 years of age.
Materials and methods: In this retrospective study, a total of 138 couples with maternal age >36 years undergoing ICSI with an antagonist protocol were included. The influences of stimulation and suppression length on the response to ovarian stimulation and ICSI outcomes were investigated. Receiver operating characteristic curve (ROC) analysis was performed to assess the predictive value of the stimulation period for achievement of implantation and pregnancy.
Results: THE GONADOTROPHIN STIMULATION LENGTH NEGATIVELY INFLUENCED THE IMPLANTATION RATE (RC: -4.200; p=0.023). The area under ROC curve (AUC) could distinguish between women with positive and negative implantation (AUC: 0.611; CI: 0.546-0.673) and pregnancy (AUC: 0.593; CI: 0.528-0.656). The threshold value demonstrated a high negative predictive value on likelihood of implantation (p=0.0032, 90% sensitivity) and pregnancy (p=0.0147, 87.1% sensitivity) when patients underwent more than 10 days of stimulation.
Conclusion: The stimulation period negatively influences the implantation rate in women older than 36 years. A stimulation interval greater than 10 days is associated with a negative predictive value for the chance of implantation and pregnancy.
Keywords: Gonadotrophins; Implantation; Intracytoplasmic Sperm Injection.