I was just in health class today and they were discussing Male Penis. And the teacher said that Airline pilots or Jet pilots or people who like to fly in high altitutdes have lower sperm count because of well high Altitude. She also said that they dont know the cause of this. So if any of you out there are having a hard time getting a son/daughter try to lay of the high altitude (flying) and where boxers not briefs. That is all.