Weight & Height Expectations

Growth charts are tools your pediatrician can use to keep track of your
child's physical growth. During each checkup, the doctor will measure your
baby’s length, weight, and head circumference. The doctor can then compare
the measurements for your baby to a chart of national averages for infants of
the same age and sex. The result is that the doctor will be able to tell you
what percentile your baby is in when compared to averages for babies around
the nation. For example, if your doctor tells you your 4-month-old is in the
86th percentile for weight, that means 86 percent of the two-month-olds in
your country weigh less, and that 14 percent weigh more. A baby that is at the
50th percentile in either height or weight is right at the national average.
Typically, parents seem to worry quite a bit about these percentages,
and that worrying is usually needlessly blown out of proportion. There are
many factors that come into play when determining where your baby’s
statistics will fall in the percentile chart. It is very important to remember
that no two babies are the same and that every child, due to body chemistry,
heredity, diet, and many other factors will grow at their own pace. Some
babies will have growth spurts right from the start and others will take a bit
longer to begin major growth periods. These measurements, charts, and
percentile points are merely guides for a doctor to help in assessing your baby’s
growth.
In addition to the measurements that your pediatrician will take during
regularly scheduled doctor visits, you may also want to track your baby’s
growth at home. Keep in mind that the measurements you take at home may
or may not be as accurate as the measurements your doctor takes, but they
can provide a certain degree of insight into the growth of your baby and many
new parents have found it to be a fascinating way to participate in the
parenting process.
Here are some tips that can help you, as inquisitive parents, track your
baby’s growth at home using commercially available scales and other
measuring devices.
If baby is too small to stand upright on the scale, you can try using this
procedure:
• With your baby in your arms, step onto a standard bathroom
scale.
• Make note of the weight displayed on the scale and write it down
on a piece of paper.
• Put your baby down and step onto the scale alone this time.
• Make note of the weight displayed and subtract this number from
the combined weight of you and your baby. The resulting number
is your baby’s weight.
To measure your baby’s length all you need to do is lay her down on a
flat surface (her changing table is a great place for this task) and stretch a
measuring tape from head to toes.
For the measuring of head circumference all you need to do is wrap the
measuring tape around your baby’s head. You should wrap the measuring tape
just above your baby’s eyebrows, so the tape falls right at the top of the ears.
What you are trying to measure is the point around his head that has the
largest circumference.
When taking your baby to the doctor your pediatrician will perform
more accurate measurements. Pediatricians do the “baby measuring thing” on
a daily basis and will be able to achieve a much more accurate result than you
will at home. This is due to the fact that they are accustomed to the things
babies do that can result in an inaccurate measurement and they have very
accurate measuring tools made specifically for the purpose of measuring the
characteristics of babies, such as proper baby scales equipped with cradles.
Your doctor will most likely take measurements several times during one visit
and average the results together to ensure accuracy and to compensate for any
discrepancies that may arise. It is crucial for the doctor’s measurements to be
as accurate as possible because a discrepancy of as little as a few millimeters
in length or a few grams in weight can make a difference where your baby falls
on the charts. Since the results of these measurements may determine
changes to your baby’s diet, and other possible changes to how your baby is fed
and treated during her first year, it is important that these results are as
accurate as possible.
Your pediatrician will measure the following characteristics of your
baby:
Weight: After calibrating the scale the doctor or nurse will place your
completely naked baby on a baby scale. There are electronic and traditional
beam-type versions of the baby scale, but most will typically have the same
type of baby holding stainless steel cradle. After your child is able to stand on
her own, your pediatrician will most likely use a standard upright scale.
Length: Like weighing, until your baby is able to stand up on his own,
your doctor will perform the height/length measurements with your baby lying
down. Your doctor may use a tape measure, much like you use at home, or
may utilize a special “baby-measuring device”, which consists of a headboard
and movable footboard to obtain the most accurate results possible.
Head circumference: This measurement will be taken in almost the same
way you did at home. The doctor will take the measurement at the point
where the head is at its largest circumference, right above the ears and around
to the back of the head where the neck meets the cranium. Usually the
pediatrician will record this measurement to the nearest 0.3 cm (1/8th of an
inch).
The head is different from other parts of the body in that the brain is
not fully formed at the time of birth and therefore the head will continue to
grow during baby’s first year. Baby’s head is a particular point of concern for
the doctor because a head that is growing too rapidly can be a sign of
hydrocephalus (water on the brain) and a head that is growing too slowly can
be indicative of nutritional or developmental problems. Regardless, you
shouldn’t be too concerned if your baby’s head appears a bit disproportional
compared to the rest of her body, as this is completely normal for the first
year of life.