Hi my son is 3.5 months old and his weight is 6.4 kg. In the first two months he gained more than 1 kg per month but this time he gained 600 gm per month. Is the weight fine. His birth weight was 3.5 kg ?

A. Dear mum, weight of 6.4 kg is absolutely fine for 3.5 months old baby, considering a birth weight of 3.5 kg. Baby should gain at least 500 grams per month and should double the birth weight by 6 months or earlier.