One testicle of 2 month old baby is 3 times larger than the other, pedia ask to wait & observe & recommeng operation. is this normal or alarming?

See below: The most common cause of scrotal enlargement in an infant is a congenital hernia or hydrocele. Some of these will resolve on their own, usually by 6-12 months of age. If it persists beyond this, it can be dealt with surgically. The pediatrician's advice to observe this for a period of time is appropriate. Hope this helps!

Hydrocele: The most common cause for inequality of testicular size is a hydrocele which is just a collection of fluid around the testicle. Oftentimes, the fluid is resorbed in time and will eventually disappear. Caution should be observed that in a few cases a hydrocele may be associated with a hernia. Although benign in nature, it may not be a bad idea to consult a pediatric urologist or pediatric surgeon.