Table 1. Summary of key characteristics from the 9 studies included in the meta-analysis.

Study	Design	Patient (n)	SRR(%)	Country	Predictive factors	Quality score
Cayan et al. [9] 2020	Retrospective Study	327	53.00	Türkiye	Age at orchidopexy, T, FSH	9
Sangster et al. [10] 2020	Retrospective Study	12	33.33	UK	Age at m-TESE, Unilateral/Bilateral, Location of undescended testes, T, FSH, Testicular volume, Interval from orchidopexy to m-TESE	7
Saber-Khalaf et al. [11] 2022	Retrospective Study	103	62.14	Egypt	Age at m-TESE, Age at orchidopexy, Bilateral, T, FSH, LH, Testicular volume, Interval from orchidopexy to m-TESE	9
Li et al. [12] 2020	Retrospective Study	18	77.78	China	Age at m-TESE, Age at orchidopexy, Unilateral/Bilateral, T, FSH, LH, Interval from orchidopexy to m-TESE	9
Ozan et al. [13] 2019	Retrospective Study	148	61.49	Türkiye	Age at m-TESE, Age at orchidopexy, Unilateral/Bilateral, T, FSH	9
Arasteh et al. [14] 2024	Retrospective Study	56	46.43	Iran	Age at m-TESE,Age at orchidopexy,Bilateral,Location of undescended testes,T,FSH,LH,Testicular volume	8
Chen et al. [15] 2022	Retrospective Study	162	48.15	China	Age at m-TESE,Age at orchidopexy,Unilateral/Bilateral,Location of undescended testes,T,FSH,LH,Testicular volume,Interval from orchidopexy to m-TESE	9
Xu et al.[16] 2023	Retrospective Study	73	68.5	China	Age at orchidopexy, Unilateral/Bilateral, T, FSH, LH, Testicular volume	8
Osaka et al.[17] 2020a	Retrospective Study	36	55.56	Japan	Age at m-TESE, Age at orchidopexy, T, LH, Testicular volume, Interval from orchidopexy to m-TESE	7

T: Testosterone;FSH:Follicle-Stimulating Hormone;LH:Luteinizing Hormone

^aData from the Osaka et al. study are presented as means (ranges) and could not be analyzed in subgroups.