Table III.

Semen variables for the men in cohort A, who participated at all ages.

Age (years)	19	21	25	29	P-value
n	61	61	61	61
Semen volume (ml)	3.2 (3.5) 0.9–8.0	3.7 (3.7) 0.8–8.7	3.6 (4.1) 1.0–8.2	3.9 (4.0) 0.2–7.9	0.69 19y versus 21y 0.01 19y versus 25y 0.02 19y versus 29y 0.19 21y versus 25y 0.26 21y versus 29y 1.00 25y versus 29y
Sperm concentration (million/ml)	54 (68) 0–309	47 (64) 0–377	56 (67) 0–225	66 (70) 0–195	0.79 19y versus 21y 0.99 19y versus 25y 0.99 19y versus 29y 0.70 21y versus 25y 0.77 21y versus 29y 1.00 25y versus 29y
Total sperm count (million)	177 (222) 0–651	182 (224) 0–753	219 (254) 0- 880	220 (264) 0–966	1.00 19y versus 21y 0.41 19y versus 25y 0.43 19y versus 29y 0.3 21y versus 25y 0.31 21y versus 29y 1.00 25y versus 29y
Motility (abc, %)	67 (65) 30–81	72 (71) 31–87	80 (78) 37–95	82 (79) 41–92	<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 0.94 25y versus 29y
Normal morphology (%)	7.5 (8.2) 4–11	7.0 (7.9) 4–11	8.0 (8.7) 4–12	10 (10.6) 6–14	0.57 19y versus 21y 0.99 19y versus 25y <0.001 19y versus 29y 0.44 21y versus 25y <0.001 21y versus 29y <0.001 25y versus 29y
Total motile count (million)	126 (145) 0–417	140 (162) 0–538	163 (198) 0–689	184 (212) 0–763	0.93 19y versus 21y 0.01 19y versus 25y 0.008 19y versus 29y 0.03 21y versus 25y 0.02 21y versus 29y 0.99 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.