Having your baby’s head measured at each doctor’s visit is standard routine for pediatric visits. During the visit, the nurse or doctor will measure the circumference of your baby’s head to determine its growth. By tracking the size over a period of time, doctors can get a better estimate of your child’s growth, rather than taking one measurement later in life.

Significance

Measuring a baby’s size of head provides a variety of data to your doctor. The growth can confirm that your baby is developing along a normal path. Smaller measurements may indicate your baby is not growing fast enough. In some cases, swelling may increase the measurement beyond your doctor’s expectations and may be a warning of a serious health concern.

Standard Measurements

While the baby head size varies from one baby to the next, doctors typically expect the head to be two centimeters larger than the chest. This proportion tends to equal out between 6 months and 2 years of age. Growth charts show percentiles for growth based on sex and age. Your doctor will determine what percentile your baby falls into by measuring height, weight and head circumference and then recording the measurements on the growth chart.

Time Frame

Pediatricians use measurements to compare each patient to national standards. Full-term babies tend to reach milestones for development and growth within certain time frames. Significant growth changes, including baby head circumference, tend to take place in your baby’s first 18 months, according to pediatrician Dr. Paul Roumeliotis. During this time, it is important to take measurements at set intervals to track growth. After your baby reaches an age of 18 months, your pediatrician may only schedule visits once or twice a year to track development.

Charts and Averages

Because children tend to develop along the same time frame, doctors have been able to create growth charts that show the normal growth based on age and gender. Doctors use different growth charts, based on preference. One growth chart maps patterns for babies from birth to 36 months of age, while another one tracks growth from 2 years of age to 26 years. Growth charts may list different percentiles from one chart to another. A baby with a head circumference in the 50th percentile is an averaged-sized infant.

Factors

Several factors can affect baby head growth. These include gender, genetics, health problems, hormones, brain development and lifestyle factors, like activity levels and nutrition. The country where a baby lives can also cause a variance in head growth. For example, babies born in third-world countries may fall into a smaller percentile than those born in America.