7 month old baby head size too big?

[nnester]

I went to the Pediatrician today and my large baby boy who has just turned 7 months old weighs 26lbs and is 29 1/2 inches long, but his head size is 50cm.   It has been large since birth but has steadily blown the charts and now he has ordered a CT scan.  My older son who at that same age had a 45cm head size so he had a larger head too but not as big as his little brothers.    What should I be concerned about?  Developmentaly the baby is doing excellent, he is very bright and is above average in his hand coordination.

[Kevin Kennedy, Ph.D.]

Inside the brain are cavities, called ventricles, and these contain cerebrospinal fluid (abbreviated as CSF). People with hydropcephalus have an excess amount of this fluid in the ventricles, and this can result in pressure within the brain and this pressure can then cause problems. However, if the intracranial pressure is normal, the condition does not pose problems. Your doctor is indicating that, while there may be excess CSF in your son's ventricles, there is not undue pressure. Yes, it would make sense to follow up with a pediatric neurologist. With some people, if the pressure becomes a problem, the fluid must be drained and this is accomplished with placement of a shunt.

[nnester]

The CT scan revealed he has Benign  Hydrocephalus, the Dr. did not elaborate much over the phone.  He said we would be watching his head size closely at the upcoming well baby checks and schedule another scan in a few months.   Can you elaborate on this condition at all.  Should I also take him to a neurologist?

[Kevin Kennedy, Ph.D.]

Apparently his development is proceeding well, and some people simply have heads that are larger than the norm without there being any problem. The CT scan will determine that and hopefully the outcome will be OK.  Watch the caloric intake, because we've learned in recent years the many medical complications that accompany overweight status in children.

[nnester]

Yes the Pediatrician has mentioned his weight and the amount of calories he intakes.  He suggested trying to give him one less bottle of formula a day or subsituting water for formula.  I tried that and he wouldn't take the water.
After his surgery at 10 weeks of age he weighed  13lbs and since that point he has really taken off in growth.  
  Tall people run in the family, my husband is 6'3" and has a muscular/thin build.  I am 5' 7" and thin.  My father's family though everyone was over 6'3".  So I think he is just going to be a tall person.  My 3 year old is the tallest one in his preschool and he was heavy (21lbs 8 ounces) at the same 7 months of age.   Now he is tall and thin
.

[Kevin Kennedy, Ph.D.]

I asked that question in order to 'track' his development over the seven-month period. While the length and head circumference are tracking in the expected direction, the weight shows a pretty dramatic shift. What does the pediatrician makle of that? Do the members of your family tend to be large in general?

[nnester]

I have a record when he was 7 days old on his head circumference which was 37cm his height was 21in and weight 7lbs 8ounces.  He was born with two birth defects, a skin tag by his ear and also a inquinal hernia which he had both repaired at 10 weeks old.

[Kevin Kennedy, Ph.D.]

One other thing: Do you recall what your son's head circumference, weight and length were at birth?

[Kevin Kennedy, Ph.D.]

Thank you for noticing the error, and the correct calculation indicates less of a concern. In other words, from your description it appears that your family may simply be genetically inclined toward larger heads than the norm, without any underlying pathology. Since the indications are that there are no developmental concerns, it looks like you can be reassured.

[nnester]

Dr. Kennedy,
I just wanted to clarify your response, the percentiles you gave were for  7 weeks, my son is 7 months of age.

[Kevin Kennedy, Ph.D.]

As you likely already know, 38.5 cm marks the 50th percentile in head circumference for infants seven weeks of age, and 40.4 cm marks the 97th percentile. So your son is considerably above the norm. Hydrocephalus and rickets would likely be two of the major concerns. It is very important that he is developing well - that is the major issue.