sasha - DS1 was 9lb 1oz (4.1kg) at birth and going by his PHR book was 4750g at 12 days old, 6.5kg at 8 weeks and 8250g at 3.5 months old ... BUT he was totally breastfed ... and I am only little and his dad was average height, so I would have worried if he was bigger ... are you and DH tall?

Anyway, now, he is one of the smaller kids in his class, and at almost 8 I don't think he has even hit 20kg yet! And he is now really thin! (and eats like a horse! )

If Kye is off the chart both weight and height, i would say he is proportionate!

ETA: DS1 was off the charts for the first three months right from the start!