TABLE 1.

Overview of findings included in the current study. Studies are grouped into animal and human section. N/A = not available, M = male, LH = luteinizing hormone, FSH = follicle-stimulating hormone, g= gram, kg = kilogram.

Author (year)	Country	Sample size	Subjects	Sex	Age	Average weight	Study setting	In Vivo/In Vitro	Model	Exposure	Results
											Sperm motility	Total sperm count	Hormones			Sperm DNA fragmentation	Testicular weight and architecture/histology
													Testosterone	LH	FSH
Animals
Ding et al. (2011)	China	48	Rats	M	8 weeks	200–250 g	Simulation on Earth	In Vivo	Tail suspension	Simulated Microgravity	N/A	Decreased	N/A	N/A	N/A	N/A	N/A/Disorganized
Fuller et al. (2019)	United Kingdom	72	Echinogammarus Marinus	M	Unknown	Unknown	Simulation on Earth	In Vivo	Beta emitter phosphorus-32	Ionizing Radiation	N/A	No change	N/A	N/A	N/A	Increased	N/A
		72	Gammarus Pulex	M							N/A	No change	N/A	N/A	N/A	N/A	N/A
Kamiya et al. (2003)	Japan	34	Mice	M	≥10 weeks	25.6 g	Simulation on Earth	In Vivo	Tail suspension	Simulated Microgravity	Decreased	N/A	Decreased	N/A	N/A	N/A	Decreased/Disorganized
Li et al. (2013)	China	36	Mice	M	12 weeks	30–35 g	Simulation on Earth	In Vivo	Carbon ion beam irradiation	Ionizing Radiation	N/A	N/A	N/A	N/A	N/A	N/A	Disorganized
Masini et al. (2012)	United States	10	Mice	M	8 weeks	Unknown	ISS	In Vivo	Space	Microgravity	N/A	N/A	N/A	N/A	N/A	N/A	Disorganized
Matsumura et al. (2019)	Japan	12	Mice	M	5 weeks	Unknown	ISS	In Vivo	Space	Microgravity	Decreased	No change	N/A	N/A	N/A	N/A	No change
Olejnik et al. (2018)	Australia	12	Ram Lambs	M	14 weeks	22.6 kg	Simulation on Earth	In Vivo	Linear accelerator producing photon beam	Ionizing Radiation	N/A	Decreased	N/A	N/A	N/A	N/A	No change/Disorganized
					20 weeks	27.5 kg					N/A	Decreased	N/A	N/A	N/A	N/A	No change/Disorganized
Ogneva et al. (2020)	Russia	Unknown	Mice	M	Unknown	Unknown	Simulation on Earth	In Vitro	Random positioning machine	Simulated Microgravity	Decreased	N/A	N/A	N/A	N/A	N/A	N/A
Ogneva et al. (2020)	Russia	560	Fruit Fly	M	2 days	Unknown	Simulation on Earth	In Vivo	Random positioning machine	Simulated Microgravity	Increased	N/A	N/A	N/A	N/A	N/A	N/A
Ogneva et al. (2021)	Russia	Unknown	Fruit Fly	M	2 days	Unknown	Simulation on Earth	In Vitro	Random positioning machine	Simulated Microgravity	Increased	N/A	N/A	N/A	N/A	N/A	N/A
		21	Mice	M	2 weeks						Decreased	N/A	N/A	N/A	N/A	N/A	N/A
Said et al. (2020)	Egypt	Unknown	Rats	M	Unknown	120–150 g	Simulation on Earth	In Vivo	Gamma Cell-40 irradiator (Cesium-137)	Ionizing Radiation	Decreased	N/A	Decreased	N/A	N/A	N/A	Decreased/Disorganized
Sasaki et al. (2004)	Japan	15	Mice	M	Unknown	25.8 g	Simulation on Earth	In Vivo	Tail suspension	Simulated Microgravity	N/A	N/A	Decreased	N/A	N/A	N/A	No change
Tash et al. (1999)	United States	Unknown	Sea Urchin	M	Unknown	Unknown	Space Shuttle Missions	In Vitro		Simulated Microgravity	No change	N/A	N/A	N/A	N/A	N/A	N/A
Tash et al. (2002)	United States	Unknown	Rats	M	13–15 months	Unknown	Simulation on Earth	In Vivo	Tail suspension	Simulated Microgravity	N/A	Decreased	No change	No change	No change	N/A	Decreased/Disorganized
Usik et al. (2018)	Russia	42	Mice	M	Unknown	28 g	Simulation on Earth	In Vivo	Tail Suspension	Simulated Microgravity	No change	Decreased	N/A	N/A	N/A	N/A	Decreased
Wakayama et al. (2017)	Japan	12	Mice	M	3 months	Unknown	ISS	In Vitro	Freeze-dried spermatozoa	Ionizing Radiation	N/A	N/A	N/A	N/A	N/A	No change	N/A
Yan et al. (2013)	China	42	Mice	M	10 weeks	30–35 g	Simulation on Earth	In Vivo	Tail suspension and Carbon Ion beam irradiation	Simulated Microgravity and Ionizing Radiation	N/A	Decreased	N/A	N/A	N/A	Increased	N/A
Humans
Boada et al. (2020)	Spain	15	Humans	M	26–40 years	Unknown	Simulation on Earth	In Vitro	Parabolic flight	Simulated Microgravity	No change	No change	N/A	N/A	N/A	No change	N/A
Ikeuchi et al. (2005)	Japan	18	Humans	M	22–40 years	Unknown	Simulation on Earth	In Vitro	Parabolic flight	Simulated Microgravity	Decreased	N/A	N/A	N/A	N/A	N/A	N/A
Kumar et al. (2013)	India	134	Humans	M	21–50 years	Unknown	Earth	In Vivo	Occupationally exposed	Ionizing Radiation	Decreased	No change	N/A	N/A	N/A	Increased	N/A
Zhou et al. (2016)	China	118	Humans	M	28.26 ± 3.12 years	78.13 kg	Earth	In Vivo	Occupationally exposed	Ionizing Radiation	Decreased	No change	N/A	N/A	N/A	Increased	N/A

Note: N/A = not available, M = males, ISS, international space station.