Do Diaper affect babys penis size??

A. Not as such Yes, you can use diaper /pampers of any good quality brand(Pampers, Huggies, Mamypoko, Cuddles), but not for the whole day. give diaper free time frequently in a day, if possible use cotton diaper, it will help to decrease diaper rash if any.  Always check every 2 to 3 hourly for urine and motion and change immediately once baby pass urine or motion.