Hyperbaric-induced subfertility in mice: lack of effect of decompression

Male mice were exposed to 50 atmospheres absolute (ATA). He for 30 min, twice weekly for 5 wk and their fertility assessed by subsequently mating with untreated virgin females. The exposure schedule was designed to provide compression and decompression times the same as previous positive studies of hyperbaric-induced subfertility but with much shorter periods at maximum pressure (30 min vs. 24 h). We postulated that, if subfertility were associated with exposure to pressure per se rather than with compression or decompression, then the present experiments would fail to produce a decrease in male fertility. The data were compared with those of a control group placed in the hyperbaric chamber at 1 ATA. The pregnancy rate for exposed vs. control mice was 89 vs. 86%, and the mean live liter size was 6.2 vs. 5.6. There were no statistically significant differences between these and other indexes of male fertility, and the results support our hypothesis that the hyperbaric-induced subfertility in male mice is not associated with these decompression procedures.