Materials and Methods: This cross-sectional comparative study enrolled 132 patients who were divided into three equal groups: normozoospermia, NOA, and oligozoospermia (n = 44 each). A comparison was made in all groups based on age, hormones, and SCF level. SCF level in serum and seminal fluid was measured by ELISA.

Results: Our research indicated the concentrations of SCF in both seminal plasma and serum across three groups. Seminal plasma SCF levels showed a significant difference between groups (P = 0.002), with higher levels observed in the oligozoospermia group compared with both NOA and normozoospermia groups; no significant difference was observed between NOA and normozoospermia. In contrast, serum ligand levels were significantly elevated in the NOA and normospermia groups compared to the oligospermia group (P < 0.001). Units are expressed as ng/mL.

Conclusions: Our findings identified that seminal plasma SCF, in contrast to its serum, was significantly elevated in oligozoospermia and may serve as a promising and direct biomarker of the active local testicular microenvironment in states of diminished sperm production.