Mean head circumference at bih is?

Head circumference: Measured with a nonstretchable tape passing through the maximum point of occipital protuberance posteriorly and at a point just above the glabella anteriorly. If the head circumference is more than expected, always measure the both parents&; head circumference, for benign familial macrocephaly is common. At bih, it is around 34 cm. HC increases by 2 cm/month for the first 3 months, 1 cm/month for next three months and 0.5 cm per month for next 6 months. Ref: Ghai Essential Pediatrics, ninth edition. pg. no. 35.