What is the normal head circumference for a 4years old microcephaly?

OFC cm: A normal range of head size for 4 yo toddler is 48 cm - 54 cm. If under 46cm the head is small, sometimes due to small head size in family (parents) or 1-2 standards below the mean is a small head, needing to be followed: 42-46 cm. Fetal infections, developmental delays can occur with small head size and not growing correctly. A pedi-neurologist can follow along with the pedi MD.

Good question : I am not sure if there is a special chart for the microcephalics, his development may have been charted before overtime and compared to normal curves, development is a complex process, and not measured only by the head circumference, other aspects of the original disease and development interact, check this link too: http://www.who.int/childgrowth/standards/second_set/cht_hcfa_boys_p_0_5.pdf