Why do so many folks refer to a baby as 'it' instead of he or she? That really bugs me.

That's just during the ET stage.  It doesn't take long for them to become a he or she.  Then it's for life.  Yes, I said for life.

  You and I think exactly alike on this one.  They certainly don't do that with adults.    If someone doesn't know the gender of an adult, does that make it right to use the word 'it'?  I like asking the people who say that, "Is there a certain age at which a child finally deserves the right not to be referred to as 'it'?  Grrrrrr.
~

Could be worse, could be 'they'. 

I use "it" for adults, when I'm not sure of the gender.  Though I'm usually also unsure whether they are human.

...

"Hey, my sister had a baby!"
"Oh, what {gender} is it?"

Fudge, fudge, call the judge;
Momma's gonna have another baby,
Not a boy, not a girl,
Just an ordinary baby!