Home HealthTopics Health Centers Reference Library Research
Join us on Facebook Join us on Facebook Share on Facebook

Children's Health

Head circumference of premature baby



My baby boy was born 6 weeks premature.At the time of birth his weight was 1.83 kgs and his head circumference was 28 cms.Now he is 4 months old.His weight is 6.24 kgs and head circumference is 37.5 cms.Please let me know if this is fine.

The doctor on his visit yesterday said that his HC is very low in the 3rd percentile which is abnormal.I Am so worried.


I appreciate how worried you must be! That is very concerning information. In rechecking the information on his birth measurements and how they plot on intrauterine growth charts, I can tell you that his birth weight, which is likely to be accurate, places your son in the growth pattern for weight that is appropriate for him as a 34 week gestation infant. So he had adequate weight gain during his time before birth. However, his head circumference, which is a measurement that is frequently inaccurate, was far below normal for his prenatal length of development. It is not even on the chart at all and is therefore well below the 3rd percentile. That could be true or that could be false depending upon the accuracy of the measurement and there is no way to know that now.

Turning to his 4-month-old measurements, and assuming that you are not subtracting his 6 weeks of prematurity from his chronological age, which really needs to be done, he is actually is a 2.5 month-old infant and his growth and development should reflect expectations for a 2.5 month-old, not a four-month-old.  Plotting his measurements on a growth chart specific for low birth weight preterm infant boys at 2.5 months of age, his weight continues to be very good, in fact it is at nearly the 95th percentile for a preterm infant boy at 2.5 months of age, with only 5 % of little preterm boys his age weighing more than he does. If you did already correct for prematurity and he really is a four-month-old, his weight nearly at the 50th percentile with about half of preterm boys four-months old weighing more than he does and about half weighing less. At 2.5 months of corrected age on the correct low birth weight boys growth chart his head circumference is a little below the 5th percentile. If he really is 4-months of age corrected for prematurity, he is below the 3 rd percentile as his pediatrician says.

So the good news is that if his head measurement at birth was correct, then he actually has experienced excellent catch up growth in his head circumference to be nearly on the growth curve when he started out no where near it. On the less positive side, his head circumference always being so small is concerning since it is an indirect measurement of the size of the brain and the size of the brain usually relates to the chances for normal functioning. However, parental genetics also influences head size. If you and the baby's father have smaller than average head sizes, the smaller head size of the baby may be only a reflection of his genetic heritage for head size and have nothing whatsoever to do with intellectual ability.

Being born early really does impact infant growth and development, even when the baby is a good size and has a trouble free time after birth. The brain is still no where near ready for life outside the mother's body and our ability to nourish a preterm infant as well as the mother's placenta does is limited. research shows that many preterm babies do have learning problems in school that are not measurable before they must deal with reading, writing, and math. Just as true is that at this point in time, we do not have the ability to predict any child's development  with any precision. We know that good parenting and good health care help the baby to achieve the most possible. So the parent's role is critical for each baby. 

I think think his doctor is correct in being concerned that there may be a problem. If a consultation with a neurologist, an MRI of your son's head, or early intervention services are recommended,  those would be good recommendations to accept to make sure that everything possible is done to identify problems early and support the well being of your son. There may be no problem at all, which would be greatly relieving to know.

I can't stress enough how important it is to take care of yourself too by seeking the support and help you need to be a happy and healthy mother for your child. You are clearly doing a great job helping him to grow well and getting him to a good doctor. However, you cannot give to him the care and love he needs if you are on empty.

I hope this is helpful!

For more information:

Go to the Children's Health health topic, where you can:

Response by:

Mary M Gottesman, PhD, RN, CPNP, FAAN Mary M Gottesman, PhD, RN, CPNP, FAAN
Professor of Clinical Nursing
College of Nursing
The Ohio State University