Table 1. Description of the interventions by treatment group of the included studies.
Comparison Study Intervention group Control group Outcomes
Protocol Type of ET Protocol Type of ET
GnRH protocol before COS and fresh ET Ultralong GnRHa protocol Long GnRHa protocol
Hou et al., 2020 Triptoreline acetate 3.75mg monthly for 3 months before COS. Cos started 30-45 days after the last GnSRHa injection Fresh Triptoreline acetate 0.1mg daily in the mid-luteal phase for 10 days followed by 0.05mg daily until de day of HCG injection. COS was started 10 days after the first GnRHa injection Fresh Clinical pregnancy rate, implantation rate, Miscarriage rate, Live birth rate
Chen et al., 2020 Triptoreline acetate 3.75mg monthly. Dose repeated up to 3 months if AP uterine dimameter was ≥ 70mm. Triptoreline acetate depot (1.0-1.8mg) or daily dose (0.05-0.1mg) was used for pituitary downregulation 28 days after the last monthly injection. COS was iniciated 14 days after the last injection for pituitary downregulation Fresh Triptoreline acetate 3.75mg monthly. Dose repeated up to 3 months if AP uterine dimameter was ≥ 70mm. Triptoreline acetate depot (1.0-1.8mg) or daily dose (0.05-0.1mg) was used for pituitary downregulation 28 days after the last monthly injection. COS was iniciated 14 days after the last injection for pituitary downregulation Fresh Clinical pregnancy, miscarriage and live birth rate
Lan et al., 2021 Triptoreline acetate 3.75 monthly for 2-4 months before COS. COS started 28 days after the last GnRHa injection Fresh Triptoreline acetate single dose of 0.93 - 1.87mg in the mid-luteal phase. COS was started 14 days after the GnRHa injection Fresh Biochemical pregnancy, implantation, miscarriage, clinical pregnancy, live birth rate
Wu et al., 2022 Triptoreline acetate 3.75mg monthly for 3 months. A 4th inhection was given if AP uterine diameter was ≥ 70mm. COS started 28 days after the last GnRHa injection Fresh Triptoreline acetate depot (1.0 + 1.8 mg) or daily dose (0.05 + 0.1mg) for pituitary downregulation. COS started 28 days after the last GnRHa injection Fresh Biochemical pregnancy, implantation, miscarriage, clinical pregnancy, live birth rate
Ge et al., 2023 Triptoreline acetate 3.75mg monthly. Dose repeated up to 6 months if AP uterine diameter was ≥ 70mm. Fresh Triptoreline acetate 3.75mg monthly. Dose repeated up to 6 months if AP uterine diameter was ≥ 70mm. Fresh Biochemical pregnancy, implantation, miscarriage, clinical pregnancy, live birth rate
Ultralong GnRHa protocol Antagonist protocol
Park et al., 2016* Gosereline 3,75 mg monthly. Dose repeated up to 3 months if AP uterine diameter was ≥ 70mm. Fresh Daily dose (0.25mg) of GnRH-ant on iniciated based on a flexible protocol, once a folicle reached ≥ 12mm and until trigger day Fresh Clinical pregnancy, miscarriage rate
Ge et al., 2023 Triptoreline acetate 3.75mg monthly. Dose repeated up to 6 months if AP uterine diameter was ≥ 70mm. Fresh Daily dose (0.25mg) of GnRH-ant on iniciated based on a flexible protocol, once a folicle reached ≥ 12mm and until trigger day Fresh (see above)
Long GnRHa protocol Antagonist protocol
Ge et al., 2023 Triptoreline acetate (0.05-0.1mg) daily dose for 14 days Fresh Daily dose (0.25mg) of GnRH-ant on iniciated based on a flexible protocol, once a folicle reached ≥ 12mm and until trigger day Fresh (see above)
Short GnRHa protocol Antagonist protocol
Ge et al., 2023 Triptoreline acetate (0.05-0.1mg) daily dose on days 2-4 of the menstrual cycleuntil HCG trigger Fresh Daily dose (0.25mg) of GnRH-ant on iniciated based on a flexible protocol, once a folicle reached ≥ 12mm and until trigger day Fresh (see above)
Pretreatment before FET Pretreatment with GnRHa No pretreatment
Niu et al., 2013* Leuproline acetate 3.75mg for 28 days followed by leuproline acetate 1.875 mg. 21 days after HRT was initiated. Artificial cycle No pretreatment before HRT Artificial cycle Implantation rate, clinical pregnancy
Li et al, 2021* Triptoreline or leuprolide 3,75mg for 28 days. Patients with larger uterine volumes were administered additional injections. Artificial cycle No pretreatment before HRT Artificial cycle Implantation, clinical pregnancy, miscarriage and live birth rate
Zhang et al., 2022 Triptoreline acetate 3,75mg monthly for 3 months before HRT. Some patients underwent FET < 3 months pretreatment Artificial cycle No pretreatment before HRT Artificial cycle Clinical pregnancy rate, live birth rate, miscarriage rate

*No data regarding the protocol for COS is provided the authors.