Calling your baby an it

Does anybody give you a lecture when you refer to your baby as an "it?" As in its heart rate was 166? I posted something like this on facebook and everybody freaked out saying it's a baby not an it. Well obviously. But I don't know what I'm having and it's easier to say "its" rather than "his or her" every time. When I find out what I'm having I'll no longer say it but for right now it makes sense to me. Nobody freaks out when people say "it's a boy" or "its a girl" how is it any different. Ugh just needed to vent lol