Several times during your baby's first two years, you will find yourself in the pediatrician's office, stripping baby down to his diaper for a weight check.  He will then be measured for height and head circumference.  The doctor or nurse will mutter something to you about percentiles and charts.  What does this mean to you?  This is merely a method for your baby's doctor to assess his growth in comparison to other babies the same age.  He will probably plot this information on your baby's personal growth chart to help him paint an overall picture of his development during the crucial first years.

The pediatrician tells you your baby is in the 50th percentile for weight.  What does this mean to you?  It simply means that 50% of the babies charted weighed less than yours and that 50% weighed more.  Do not be alarmed if your child is in a lower percentile or "off the charts" .  This does not mean your baby is under- or over-weight or that he is destined to be big or small as an adult.  The pediatrician will compare height, weight, and head circumference for an overall picture of your baby's development.  He will look for sudden increases or decreases in these three measurements as an indication that there may be an undetected illness.  

There are many other factors that determine your baby's overall health such as developmental milestones, appearance, and activity.  If you have any concerns about your baby's size or development, be sure to discuss them with the pediatrician.