Table 3. Comparison of fertilization between the two groups
Variable 2000-2002 (n=764) 2010-2012 (n=1536) p-value
Male age (y-old) 35.0 ± 8.6 35.3 ± 8.1 0.318
Days of abstinence 4.2 ± 3.1 4.2 ± 2.7 0.777
Sperm sample volume (ml) 3.4 ± 1.8 3.3 ± 1.6 0.473
Sperm concentration/ml (million) 61.7 ± 69.4 26.7 ± 27.3 <0.001
Total sperm concentration (million) 183.0 ± 197.0 82.8 ± 89.5 <0.001
Progressive sperm motility (%) 36.4 ± 18.3 36.5 ± 19.2 0.812
Normal morphology (%) 4.6 2.7 <0.001
Incidence of azoospermia (%) 38/764 (4.9) 131/1536 (8.5) 0.001
Incidence of severe oligozoospermia (%) 114/726 (15.7) 426/1405 (30.3) <0.001
Note: values are mean ± SD, unless otherwise noticed. SD: standard deviation.