Kids come in all sizes and shapes, including babies. One area that causes the most concern is head size, especially when the head is small. Here are two typical examples:
Baby A was born at 38 weeks by IUR and was delivered by c/section for having a small head noted prenatally. He was 5lbs 13 oz. and 19.5 inches long. He has grown on a normal curve but his head circumference has been just below the curve since he was born. He seems very content and has for the most part developed normally. His head at 8 months is about 42 cm. Baby A's parents are not sure what to make of this but are concerned with the small head size.
Baby B is a two month old born at term. At the 2 month visit, his doctor said his weight and length are good but his head size, 15 inches is a bit on the low side, in the 25th percentile. It was 14 ˝” at his 2 week visit. She didn’t seem worried and said she’d keep an eye on it over time. Baby B is also developing normally. The mom of this baby is worried that her baby's small head will mean later developmental problems.
Both babies share an important similarity: they are meeting their milestones. This is most certainly the most important indicator that a baby's brain is developing well.
Growth parameters can be difficult to evaluate and can cause alarm if you are not quite sure what to make of them. Growth curves represent the entire population so some kids will fall on the high end, some on the low end, and many in the middle. What we look for is the pattern over time and not just the isolated percentage. Also important is prenatal history and birth history. Many babies are born with IUGR and catch up nicely over time. Baby A, the baby's head is actually tracking along the growth curve which is very reassuring.
One of the advantages of the frequent infant well child visits is to catch infants early who may need some early intervention and help with milestones. Pediatricians monitor this very closely and many states have early intervention to help at risk babies maximize their development during the infant period. This is important for premature babies and babies who are not meeting their milestones on time.
Babies thrive when loved and nurtured. That above all is what determines later success in life. Intelligence has a great deal to do not only with nurturing when young but genetics. All any of us can do is accept our kids for whatever learners they end up being and help them be the best they can be. Both these babies will look just like all the other kids when he is in school!
If you flash forward a few years, I'll let you in on a secret: you won't be able to tell baby A or B from any other child. There are so many variations of head size that kids end up just looking like they've fit in their entire lives!