I am Peruvian, and we have the same cultural norm as your husband. In Peru, baby girls actually get their ears pierced the day they are born - a nurse does it at the hospital. Or the parents/relatives do it a few days later at home. So I've had my ears pierced since birth. I am one to question any kind of cultural norm and will not impose this on my baby girl (hubby and I are having our 1st baby, a little girl) simply because it makes no sense to me. I think it's mostly done to "beautify" the baby, and to be able to tell right away wether it's a boy or a girl. Whatever the argument, I will not hurt my baby in such a way. I am doing the best I can taking care of her in utero and loving her....why would I purposefully hurt her by piercing her flesh?
Since in your case, it is your husband pushing the issue....discuss the rationality of the matter. Is it really rational to put your baby through pain just to fulfill a social norm? It's not something that is medically necessary...it's simply one of those things that every culture has, that when questioned doesn't really have a good basis on which to stand. If he really want her to wear ear rings, they do have the pain free sticker kind, and the pressure kind.
I'm sure your baby girl is beautiful without the need of pierced adornments.
Good luck with hubby.