I notice my baby boy testis I mean the scrotum is big right from birth. It is something to worry about?
First you have to let a Paediatric Surgeon examine him, because a swollen scrotum may be a hernia or a hydrocele. Treatment(surgery) is similar but the timing is different. A hernia may need to be repaired earlier to prevent complications. There is really no way to prevent it occurring again.
Hydroceles are not hereditary but a small percentage occur in some families, especially among male siblings and twins.