hlo my baby is born a preemie at 7 months and his weight was 1.5 kg and currently his weight is 5.1kg is it good weight gain or should I consult a paediatrician

A. It is amazing I can confirm on that though the weight was less than the child was born before time a child is literally gained almost 4 kg in four months which is amazing because the minimum expectation is 500 to maximum it 1 kg which is not very commonly right now this is amazing