Personal choice. Circumcision can be beneficial for hygiene reasons, fewer infections, etc, as mentioned previously. Also, there are social issues to consider. Since most boys are circumsized will your son feel different if he isn't? These are things to consider. But, if it's to be done, it's best to do it in the newborn stage because the procedure is a difficult thing to endure for adult males.
Preventative if any. Circ rates run 0-80% depending on cultural, religious& healthcare practices around the world. The only males with uti's i've treated in 3 decades were uncircumcised & often .