P-008 Microgravity exposure significantly decreases sperm motility and vitality. Can we consider human reproduction outside the Earth?

Abstract Study question Are fresh human sperm samples affected by different gravitational conditions than on Earth? Summary answer Motility and vitality of are significantly decreased under microgravity obtained parabolic flight. What is known already Microgravity effects the male reproductive system have mainly been studied in animal model with diverse results discouraging extrapolation humans. While an increased motility was reported bulls, mice models showed a decrease. Although preliminary data from Micro-11 experiment presented NASA alterations after exposure, our first study failed to show any significant effect “frozen” samples, suggesting that could be safely shipped outside earth if important aspects related cryopreservation were solved. design, size, duration Prospective carried out collaboration between ART centre, Technical University, Aviation Club specializing flights.Two flights conducted 2020-2021, each consisting 20 maneuvers, which means 160 seconds exposure per sample. Fifteen healthy men included order analyse compare those Earth gravity. Participants/materials, setting, methods Fresh checked pre-flight evaluate vitality, concentration, morphology. Samples split into two gravity exposure: (flight) (ground). After flight, same analysis repeated, plus kinematics, DNA fragmentation chromatin dispersion, apoptosis magnetic activated cell sorting, oxidative stress colorimetric test (Halosperm-Halotech). Computer Aided Semen Analysis (SCA-Scope) used for counting. Main role chance On comparison mean values exposed maintained gravity, statistical differences (p < 0,05) found following parameters: (69,7 ± 9,9 vs 72,4 9,7 %), motile concentration (23,7 15,3 M/ml 31,5 25,1 M/ml), grade “a” (8,7 6,5 11,7 percentage spermatozoa progressive (30 12,9 36 14,3 curvilinear motility-VCL (45,7 12,8 47,7 13,3 μm/s). Under conditions, non-statistically observed other kinematic Lineal Velocity (VSL), Average Path (VAP), Straightness (STR), Amplitude Lateral Head displacement (ALH), Linearity (LIN), Wobble (WOB), Beat-Cross Frequency (BCF), total (81,7 112,1 79,7 89,8 morphology (11,3 6,3 10,6 5,3%), (14,6 9,6 15,7 9,4), (2,8 2,8 3,8 4,4) stress, since all level both splits. Limitations, reasons caution Parabolic flight accepted ground-based method obtaining but provides short period elapsed microgravity. Therefore, need confirmed using platforms provide much longer time exposure. More cases must analysed confirm results. Wider implications findings Short decreases vitality. Such likely stronger These should taken account this may eventually affect fertilizing capacity therefore natural conception or fresh/frozen sperm, Earth. Trial registration number NCT03760783