L.A.
As everyone else has already said, with proper hygiene, circumcision is not necessary. But here's something I bet most folks don't know -- WHY circumcision became such a big fad. Answer? Back in the late 1800s there was this big obsession with preventing children from masturbating -- it was supposed to spiritually stain them and corrupt their moral fiber. And distract them for doing their long list of chores.
So some creative nits with nothing better to think about decided the best way to nip it in the bud was to mutilate the genitals of children -- boys and girls -- who wouldn't stop in response to mere beatings. Quite horrible and in some cases severe. Distressed at being "forced" to go to these extremes, they decided keeping boys (the more common offenders) from discovering this "terrible vice" was all important.
They then started writing books and going on the lecture tour. They helped popularize the notion that circumcized boys wouldn't be so prone to "explore" because they never had to clean the foreskin... and thus never accidentally discovered the pleasurable sensations that it had.
So it became fashionable, and morally correct, to have it removed.
Then in the 1940s, as American GIs were stationed in the hot humid battle zones of the Pacific (Guam, Hawaii, etc.), it was discovered that some GIs had problems with keeping themselves clean enough "down there" and were getting fungus issues. It was also thought that they would more easily pick up diseases from the local girls if they had foreskins because-- okay well let's not get that detailed.
I would note that these same GIs were getting fungus in a lot of other places as well and no one thought amputation was the right suggestion (toes for example). But the puritanical attitude about the body didn't make rubbing cream into the toes seem quite so naughty...
Anyway, my point is this is not a medical necessity. It is a cultural convention. One that historically has much to do with anti-sex and anti-sensuality attitudes.
Interestingly, many uncircumcized adult men report much greater pleasure sensitivity.
Sorry if this was a little too "racy" for some. But I think it's important that we know where our inherited attitudes are really coming from on this issue. So that parents with boys can make an intelligent and rational decision -- whatever that may turn out to be.
I think we all should realize however that uncircumcized is the natural state of things -- and is the norm in most cultures on Earth -- and it works quite well.