Baby Head Circumference: The Best Guide for Singaporean Parents

Baby’s head circumference is one of the first measurements taken at birth because it provides valuable insight into your baby’s brain development.

This guide reveals what a normal baby head circumference looks like and how to read a baby head circumference chart. With the right information, you can better understand your baby’s growth and feel more confident at every developmental check-up.

How Is Baby Head Circumference Related to Brain Development?

During the first two years of life, your baby’s brain grows rapidly, reaching around 80% of its adult size by age 2^[1]. As the brain grows, the skull expands to make room for it, which is why your baby’s head circumference is measured at every well-baby visit.

A healthy increase in baby head circumference usually reflects normal brain growth. However, head circumference alone cannot measure intelligence or brain function. Doctors assess it together with your baby’s weight, length, developmental milestones, and overall health to get a complete picture of their development.

The fastest head growth happens during the first year, especially in the first few months of life. After your baby’s first birthday, growth naturally becomes much slower.

If your baby’s head circumference is much smaller or larger than expected, or if it changes suddenly over time, your healthcare professional may recommend further assessment. While these measurements are often simply part of your baby’s natural growth pattern, they can occasionally indicate conditions that need closer monitoring.

Remember: The most important sign is not one measurement, but a steady pattern of growth over time.

When and How To Measure Baby Head Circumference

Head circumference, also known as the fronto-occipital circumference (OFC), reflects the progress of a baby’s central nervous system.

The first time your newborn’s head is measured is typically shortly after birth. The medical staff will take the measurement quickly, as the comparison charts are based on measurements taken within the first 24 hours of a baby’s life^[2].

Apart from that, a baby’s head circumference is also commonly measured at the following times:

• At well-baby and well-child appointments
• At 6-8 weeks check
• At around 6 months
• If there are concerns over the baby’s development, such as head control or slow weight gain.

Parents can measure their baby’s head circumference at home, if they want, by following these steps:

• Step 1: Prepare a flexible, non-stretchable measuring tape. Place the baby in a calm and upright position, either sitting on a caregiver’s lap or lying down comfortably.
• Step 2: Locate the widest part of the baby’s head. This typically includes the area just above the eyebrows (supraorbital ridge) at the front and the most prominent part of the back of the head (occiput).
• Step 3: Place the tape snugly around the head, ensuring it lies level all the way around. Avoid compressing the skin, but ensure there are no gaps.
• Step 4: Note the measurement in centimetres or inches where the tape meets its starting point.

Expert tip: Parents can repeat the process for more accurate results. Log the largest reading for comparison with growth charts to track development.

For further details, check out the CDC’s tutorial:

What’s A Normal Baby Head Circumference?

According to HealthHub, the circumference of a Singaporean newborn’s head averages from 32 to 36cm^[2].

Typically, a baby’s head size is about half their body length in centimetres plus an additional 10 cm.

For example, a newborn measuring 45.7 cm would have an estimated head circumference of about 32.9 cm. This proportional relationship provides a general guideline for head size relative to body length.

Another way to estimate a baby’s normal head circumference is based on their chest measurement^[3]:

• A newborn’s head circumference is typically about 2 cm larger than their chest measurement.
• Between the ages of 6 months and 2 years, the head and chest measurements generally become equal.
• After 2 years, the chest circumference surpasses the head size, reflecting normal growth and development patterns.

What if you want to compare your little one’s head circumference with their peers? The best way is to use the WHO’s Head circumference for age charts. These charts are published based on data from healthy, exclusively breastfed infants across six countries and five continents to show typical infant growth patterns ^[4].

There are two types of charts – percentile charts and z-scores:

• Percentile charts use percentile lines to show the percentage of observations that fall below a certain value. It includes the 3rd, 15th, 50th, 85th, and 97th percentiles.

• Z-score charts use z-score lines to show the distance and direction of an observation away from the population mean. Positive z-scores represent values above the mean, while negative z-scores represent values below the mean.

These charts display the average baby head circumference for boys and girls at different ages. They help your baby’s doctor compare your baby’s head size to the typical range for their age and monitor how it changes over time to assess overall growth and development.

If you find these charts hard to understand, check out this simplified field table:

When Should I Be Concerned About Head Circumference?

If your baby’s head is much smaller than average, it could indicate that their brain has stopped growing or isn’t developing properly. This may be caused by an infection or a genetic condition.

On the other hand, an enlarged head size might be caused by increased pressure inside the skull^[3]. It signals hydrocephalus, a rare condition where fluid builds up in and around the brain^[5]. Signs to watch for include:

• Downward eye movement (also known as “sunsetting eyes”)
• Irritability
• Vomiting

Other possible causes of an unusually large head include brain tumors or genetic conditions. In those cases, you’ll likely be referred to a pediatric neurologist or neurosurgeon for diagnosis and treatment.

Be sure to talk with experts about your baby’s head measurements and accompanying symptoms to determine the underlying cause and appropriate interventions.

Nevertheless, even if your baby’s head size is not at or near the 50th percentile, it could just mean they have a smaller or bigger head, as long as they are meeting developmental milestones.

Learn more about developmental milestones and nutrition for babies:

• Aged 0-6 months
• Aged 6-12 months
• Aged 12-18 months
• Aged 18-24 months

Remember, tracking head growth over time can often provide more valuable insights than a single measurement that surpasses normal expectations.

Support Your Baby’s Growth with Connection and Care

Supporting your baby’s development doesn’t require a strict routine, but consistency, connection, and care make a big difference. Here are some simple practices to support your baby’s natural growth and development every day:

• Skin-to-skin contact regulates your baby’s heart rate and reduces stress.​
• Baby massage improves circulation, sleep, and bonding.​
• Tummy time builds core strength and motor skills.​
• Use of gentle products helps protect delicate skin and avoid irritation.
• Safe sleep ensures your baby gets enough rest for growth and brain development.​
• Gentle play encourages sensory exploration and curiosity.​
• Hydration keeps the body functioning properly, especially during growth spurts.

FAQs about Average Baby Head Circumference

1. Why is baby head circumference important?

Head circumference is an easy and cost-effective way to monitor a baby’s brain growth and development. It provides a baseline for measuring changes over time and helps identify problems like hydrocephalus or microcephaly.

2. What is the head circumference of a baby in Singapore?

HealthHub reports that the average head circumference of a newborn in Singapore ranges from 32 to 36 cm^[2].

3. Can I measure baby head circumference at home?

Yes, parents can measure it at home using a flexible, non-stretchable measuring tape. However, home measurements may not always be as accurate as clinic measurements. If you are concerned, ask your doctor or nurse to check it during a well-baby visit.

4. How often should baby head circumference be checked?

Baby’s head circumference is usually checked at birth and during routine well-baby visits. Your doctor may check it more often if there are concerns about growth, development, or changes in head size.

5. When does a baby’s head circumference stop growing?

By 1 year of age, head circumference shows the highest level of developmental progress, reaching 87.5% of its adult size. Growth in head circumference continues at a mild pace throughout childhood but is mostly complete by the time a child reaches maturity^[6].

Disclaimer: This guide is for informational purposes only and should not be used to diagnose health conditions or make changes to medical treatments. Always consult with your healthcare professional for advice.