âIf they are skittish they should arrange a visit with their family doctor or paediatrician.â âAlison usually wasn't so skittish, but people around her didn't often fall prey to killers bent on revenge.â
Birth. The average newborn is 19.5 inches long and weighs 7.25 pounds. Boys have a head circumference of about 13.5 inches and girls measure in at 13.3 inches, according to the National Center for Health Statistics.1  Baby Growth Charts: Calculate Height and Weight. 2  Charting Baby's Development.irth. The average newborn is 19.5 inches long and weighs 7.25 pounds. Boys have a head circumference of about 13.5 inches and girls measure in at 13.3 inches, according to the National Center for Health Statistics.
According to the CDC growth charts the 50th weight-for-age percentile for a 4-month-old baby boy is approximately 15 Ibs., and for infant girls about 13.5 Ibs. Concerns Four-month-old babies who display short stature, underweight, overweight or at risk for overweight may require further evaluation or have an underlying health problem.