A Retractile Testicle is one that will not stay down in the scrotum where it belongs, so your doctor should be checking your son's testicles at every physical. During the first year of life this is critical, because if the testicle has not come down into the scrotum by the first birthday they might refer them for a surgery. Your doctor should continue to check your sons testicles throughout his life at every 'well-child' check to make sure he doesn't have a retractile testicle. If a testicle can be brought down into the scrotum but then goes right back up, that testicle might require surgery as well. The problem with a retractile testicle is if a testicle spends most of its time near the body instead of being in the scrotum, the higher temperatures can actually decrease his sperm counts later in life and he might have trouble having babies.