Is There Any Effect of Change in Pre-Wash and Post-Wash Semen Parameters on the Success of Intrauterine Insemination?

(1) Background: We aimed to investigate the effect of change in pre-wash and post-wash semen parameters on intrauterine insemination (IUI) success in a homogenous study group. (2) Methods: IUI cycles conducted at an infertility clinic were included in this study. Patient records were examined retrospectively. Δ sperm count (per mL) was calculated as [pre-wash sperm count (per mL)-post-wash sperm count (per mL)]. Δ Total progressive motile sperm count (TPMSC) was also calculated as (post-wash TPMSC-pre-wash TPMSC). (3) Results: No statistically significant difference was detected in terms of Δ sperm count (p = 0.38), and Δ TPMSC (p = 0.76) regarding the clinical pregnancy rate (CPR). There was no statistically significant difference between CPR (+) and CPR (-) groups in terms of post-wash sperm count, TPMSC, TPMSC ≥ 10 × 10⁶, TPMSC ≥ 5 × 10⁶ (p = 0.65, p = 0.79, p = 0.49, p = 0.49, respectively). The live birth rate (LBR) showed no statistically significant differences except for a pre-wash TPMSC ≥ 10 × 10⁶ (p = 0.02). Through the performed ROC analysis, no statistically significant cutoff value could be set for the pre-wash TPMSC. (4) Conclusions: There is only a pre-wash TPMSC ≥ 10 × 10⁶ that showed a significant role in the success of IUI, even when considering all other pre-wash and post-wash semen parameters. Δ sperm count and Δ are not useful markers for IUI success.