Table 1.

Comparison between normozoospermic frozen samples exposed to microgravity (μg) and the control group maintained on earth conditions (1 g): sperm concentration and motility after thawing

	μg		1 g
	Mean ± SD	[Range]	Mean ± SD	[Range]	DIF [95% CI]
Total sperm concentration (M/ml)	39.01 ± 32.02	[11.04–115.90]	39.29 ± 36.53	[8.90–127.74]	0.28 [−3.40; 3.96]
Motile sperm concentration (M/ml)	13.72 ± 12.57	[1.20–43.58]	13.03 ± 12.13	[0.86–37.86]	− 0.69 [− 2.9; 1.52]
% Motility	32.82 ± 14.19	[10.85–50.18]	32.27 ± 15.84	[9.77–62.28]	0.09 [− 0.12; –0.30]
Grade a sperm concentration (M/ml)	5.80 ± 6.40	[0.25–23.74]	5.22 ± 5.58	[0.36–21.03]	− 0.58 [− 1.28; 0.12]
Grade b sperm concentration (M/ml)	3.46 ± 3.15	[0.20–9.70]	4.03 ± 4.16	[0.19–14.67]	0.58 [− 0.96; 2.11]
Grade c sperm concentration (M/ml)	4.47 ± 4.18	[0.36–13.93]	3.78 ± 3.22	[0.32–9.52]	− 0.69 [− 1.93; 0.55]
Progressive motility (a + b) (%)	21.83 ± 11.69	[5.35–37.37]	22.54 ± 12.83	[6.21–45.10]	0.03 [− 0.08; 0.15]