Brought Kolby for his 4th mth vaccine yesterday. He weighs 6.4kg and stands 59cm tall which is consider quite small build as he falls in the 25 percentile. I am alright with his small built but what make me more worried is his head circumference is a bit small. Less than 3 percentile, at 4mth old, his head only measures 38cm. There is a small growth of 3cm from his 3th mth assessment which the nurse asked me to monitor. I did a Google about it, too small head circumference is called Microcephaly. It affects the brain development and it freaks me out. Praying hard that his head grows and he is mainly small head. Kolby looks absolutely well. Or it is too young to tell. I cannot help to think negatively. Love his smile!