Introduction: According to 2010 WHO reference values for human semen characteristics, teratozoospermia is defined when spermatozoa with morphologically normal forms are <4%. Isolated teratozoospermia (iTERATO) is frequently associated with infertility, fertilization success at ART and increased markers of sperm damage (i.e., sperm DNA fragmentation index (SDF) or reactive oxygen species). We aimed to assess the prevalence of and the clinical and hormonal characteristics of men with iTERATO seeking first medical help for primary couple’s infertility.
Methods: Data from 1857 primary infertile men (median (IQR) age 37 (21-41) years) were analyzed. Health-significant comorbidities were scored with the Charlson Comorbidity Index (CCI). Semen analysis, srum hormones and SDF (with SDF =30% at SCSA = pathologic) were investigated in every patient. A complete blood count was requested for every man and the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and the monocyte-to-eosinophil ratio (MER) were calculated. Data from a cohort of 103 age-matched fertile men was also collected. Descriptive statistics tested the association between clinical and hormonal characteristics in patients with iTERATO, and either isolated oligozoospermia (iOLIGO) or asthenozoospermia (iASTHENO).
Results: Of 1857 patients, 223 (12%), 83 (4.5%) and 258 (13.9%) had semen parameters suggestive for iTERATO, iOLIGO and iASTHENO, respectively. Of 103 fertile men, iTERATO was found in 37 (35.9%) cases. Patient’s age, BMI and CCI were comparable between groups. iOLIGO patients reported both higher median FSH (7.8 vs. 4.3 vs. 4.5 mUI/mL; p=0.001), LH (4.6 vs. 3.4 vs. 3.9 mUI/mL; p=0.001), but lower InhB levels (106.4 vs. 167.1 vs. 153.4 pg/mL; p=0.001) compared to iTERATO and iASTHENO, respectively. Total testosterone and SHBG were similar among groups. Higher median SDF values (37.5 vs. 19.8 vs. 26.4%; p=0.001) and higher rates of pathologic SDF (44.0% vs. 20.5% vs. 34.0%; p=0.04) were more frequently observed in iTERATO than in both other groups. Median C-reactive protein (0.9 vs. 0.3 vs. 0.4 mg/L), NLR (2.1 vs. 1.6 vs. 1.8) and PLR (120.2 vs. 109.5 vs. 115.1) values were higher in patients with iTERATO than iOLIGO and iASTHENO, respectively. At Sperman’s correlation, sperm morphology was inversely associated with SDF (rho –0.25; p=0.001) and NLR (rho –0.14; p=0.02). In the fertile cohort, NLR, PLR and MER were comparable between iTERATO vs. non iTERATO individuals.
Conclusions: One out of ten men seeking medical help for primary couple’s infertility reported semen parameters suggestive for iTERATO. iTERATO is even more prevalent in fertile men. Infertile patients with iTERATO had increased levels of SDF and inflammatory serum markers compared to those with iOLIGO and iASTHENO. Our findings suggest a significant link between sperm morphology and oxidative balance in infertile men. Source of