1. Alterations in sperm motility after acute oral administration of sildenafil or tadalafil in young, infertile men 
Giorgio Pomara, M.D., Girolamo Morelli, M.D., Domenico Canale, M.D., Paolo Turchi, M.D., Carolina Caglieresi, Ph.D., Cecilia Moschini, Ph.D., Giovanni Liguori, M.D., Cesare Selli, M.D., Enrico Macchia, M.D., Enio Martino, M.D., Francesco Francesca, M.D. 
Fertility and Sterility 
Volume 88, Issue 4, Pages (October 2007)
DOI: /j.fertnstert
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

2. Figure 1
Sperm rapid-progressive motility (class a) in basal conditions, after sildenafil, and after tadalafil: the difference is statistically significant (Friedman χ2, 19.1, P<.0001). Sildenafil is correlated with a statistically significant increase, compared with baseline (median value, 18.5% vs. 10.5%; Wilcoxon z-value, −3.42; P=.0006), whereas tadalafil is correlated with a significant decrease (median value, 6.0% vs. 10.5%; Wilcoxon z-value, −2.76; P=.006). Correspondingly, the difference between sildenafil and tadalafil is even more statistically significant (Wilcoxon z-value, −3.68; P=.0002). (A) Individual data. (B) Box plot with median value and with 25th and 75th percentiles.
Pomara. Sildenafil, tadalafil, and seminal parameters. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions

3. Figure 2
Sperm total-progressive motility (classes a+b) in basal conditions, after sildenafil, and after tadalafil: the difference is statistically significant (Friedman χ2, 16.3, P=.0003). Sildenafil is correlated with a statistically significant increase, compared with baseline (median value, 37.0% vs. 28.5%; Wilcoxon z-value, −2.60; P=.009), whereas tadalafil is correlated with a significant decrease (median value, 21.5% vs. 28.5%; Wilcoxon z-value, −2.41; P=.015). Accordingly, the difference between sildenafil and tadalafil was even more statistically significant (Wilcoxon z-value, −3.48; P=.0005). (A) Individual data. (B) Box plot with median value and with 25th and 75th percentiles.
Pomara. Sildenafil, tadalafil, and seminal parameters. Fertil Steril 2007.
Fertility and Sterility  , DOI: ( /j.fertnstert )
Copyright © 2007 American Society for Reproductive Medicine Terms and Conditions