Table II.

Semen variables for men in cohort A at different ages.

Age (years)	19	21	25	29	P-value
n	336	179	181	111
Semen volume (ml)	3.0 (3.3) 0.5–8.5	3.4 (3.5) 0.6–9.9	3.5 (3.8) 0.7–9.9	3.5 (3.8) 0.2–8.7	0.06 19y versus 21y <0.001 19y versus 25y <0.001 19y versus 29y 0.09 21y versus 25y 0.21 21y versus 29y 1.00 25y versus 29y
Sperm concentration (million/ml)	60 (72) 0–515	56 (65) 0–377	51 (64) 0–225	70 (71) 0–195	0.37 19y versus 21y 0.61 19y versus 25y 0.81 19y versus 29y 0.98 21y versus 25y 0.20 21y versus 29y 0.27 25y versus 29y
Total sperm count (million)	193 (219) 0–1380	184 (217) 0–753	187 (239) 0–1345	219 (251) 0–966	1.00 19y versus 21y 0.46 19y versus 25y 0.06 19y versus 29y 0.52 21y versus 25y 0.08 21y versus 29y 0.63 25y versus 29y
Motility (abc, %)	66 (64) 1–87	72 (70) 15–92	78 (76) 19–95	82 (79) 36–94	<0.001 19y versus 21y <0.001 19y versus 25y <0.001 19y versus 29y <0.001 21y versus 25y <0.001 21y versus 29y 0.21 25y versus 29y
Total motile count (million)	124 (144) 0–800	128 (154) 0–538	138 (182) 0–942	184 (199) 0–763	0.47 19y versus 21y 0.002 19y versus 25y <0.001 19y versus 29y 0.13 21y versus 25y <0.001 21y versus 29y 0.23 25y versus 29y

P-value <0.05 is considered significant, shown in bold. Results are shown as median (mean) and range. Mixed model of repeated measures analyses following a square root transformation was used. P-values for pairwise comparisons were adjusted using the Tukey–Kramer methods. For other adjustments see statistical methods.