Infants grow rapidly from the day they are born, but if you compare your child to other babies, you probably will notice a significant difference in size. Children come in all shapes and sizes and grow at different rates. To determine that your baby's growth is within the "normal" range, your physician will compare his height, weight and head circumference to other children using growth charts. These charts allow physicians to identify low growth quickly and seek appropriate solutions.
Growth charts are one tool used by physicians to determine if your child is growing at a healthy rate. For newborns to children age 3, growth charts include three variables: height, weight and head circumference. The growth chart shows the doctor how your infant is growing compared to other babies of the same age and gender. It also allows you to track your child's development over time.
About Head Circumference
Head circumference, or occipital-frontal circumference, is a measurement of your baby's head just above the eyebrows and ears. Measurements outside the range of "normal" can indicate several health problems, including water on the brain, called hydrocephalus, or unusually small cranial size, called microcephaly. Head circumference measurement will be part of well-baby check-ups until your child turns 3.
Normal Head Circumference
For the first six months of your baby's life, his head will measure approximately 2 centimeters bigger than his chest. From age 6 to 24 months, his head and chest will have about the same circumference. After two years, the baby's head will measure smaller than his chest. One measurement outside of the range of normal does not necessarily indicate a problem. Your physician will keep a careful eye on your child's development to see if his head circumference is consistently abnormal over several months.
Many factors can impede growth and development in infants, including poor nutrition, infection, disease, emotional distress and endocrine dysfunction. If your physician notices that your child is consistently on the low end of the growth charts, he may recommend a change in diet and order blood work, urine and stool samples and X-rays to isolate the cause of your baby's delayed development.