The use of aniline blue chromatin condensation test on prediction of pregnancy in mild male factor and unexplained male infertility.

The aim of this study was to investigate the possibility of using sperm function tests (hypoosmotic swelling test [HOS], aniline blue [AB] staining test, and sperm chromatin dispersion [SCD]) to predict intrauterine insemination [IUI] success rate. A total of 243 couples with mild male factor or unexplained male infertility who underwent IUI were evaluated prospectively. The results of basic sperm analysis and sperm function tests were compared between pregnant or nonpregnant groups. The HOS (11.9 ± 9.6% vs. 10.1 ± 8.5%, p = 0.35) and SCD tests (32.9 ± 21.0% vs. 29.9 ± 19.0%, p = 0.48) were not significantly different between pregnant (n = 22) and nonpregnant (n = 221) groups. However, the AB staining negativity rate was significantly higher in the pregnant group compared to the nonpregnant group (35.2 ± 20.8% and 24.4 ± 18.0%, p = 0.008). On ROC analysis, a cut-off value of 24% for AB negativity showed a sensitivity and a specificity value of 82.35% and 51.38% (AUC) = 0.653; 95% confidence interval: 0.571-0.72 P (Area = 0.5) = 0.0267, respectively, for prediction of pregnancy. Our study showed that the sperm chromatin maturity, assessed by AB stain, may predict the pregnancy in couples with unexplained female infertility plus mild male factor or unexplained male infertility. The HOS and SCD failed to predict the pregnancy in this group of couples.