Now you have seen these standard recommendations, I would suggest
you look at your child and use your judgment as to whether your baby should move up to
the next seat. I had a patient of mine who weighed 40 lbs at 7 months old. There is no way
he would fit in the seat for his weight. And an infant could be too long and
outgrown it's car seat, but the baby is not yet 20 lbs. I think the seats should be
sold based on the length of the baby and not based on the weight.
If you baby has outgrown your seat and fits the next size seat, then move him
up. The main idea is that the straps hit his body where they are
supposed to make contact in order to hold him in the seat. It's just common sense. ....
We want the lap belt to be over the pelvis and not on top of the abdomen. See
the following link to Highway safety research site.
Many authorities recommend keeping them facing backwards as long as they are
able to. It would be safer to keep them backwards to 18-24 months.