You wouldn’t think it, but even the littlest things can effect your attempts to get your partner pregnant. One of the most common impeding factors for men is underwear that fits too tightly. Semen and sperm production are at their best when everything has an adequate amount of room down there. The fact that the scrotum naturally retracts to get away from the body when it’s too warm shows how important the temperature really is. If you’re forcing everything to be as tightly bundled as possible, you can alter just how effective your sperm counts are.
Obviously, if you’re trying to have a baby then you should switch to some looser fitting underwear. Knit cotton boxers are among the best for giving everything the room that’s needed. You might even want to go a size up just to be safe, provided the band is secure enough not to leave them slipping off of you all day. You can bolster this by also changing to looser pants, especially when it comes to whatever you happen to wear when lounging around in the evenings. Nice pajama bottoms or loose sweat pants will do the trick every time.