The value of head circumference measurements after 36 months of age: a clinical report and review of practice patterns.

OBJECT The cranium is documented to grow from birth through adolescence. The standard of practice in primary care is measuring head circumference and plotting growth using curves that stop at 36 months. The authors report the importance of their experience with measuring head circumference in the child and same-sex parent beyond 36 months. METHODS In the University of Florida genetics and pediatric neurosurgery clinics, head circumference is measured and plotted on growth charts through 18 years of age. Circumference and rate of growth over time are compared with those of the same-sex parent. A diagnostic workup is initiated if there is a discrepancy with the patient's head circumference or if there is significant change in the growth rate of the cranium. RESULTS Between January 2004 and December 2007, the lead author examined 190 patients referred by pediatricians and/or pediatric subspecialists because of the concerns regarding head size of the child. Neuroimaging was performed in 70% of the patients prior to referral. None of the patients had their head size compared with that of their same-sex parent prior to referral. On assessing referring physician responses as to why the same-sex parents, head measurements were not pursued prior to imaging or referral to the specialists, the results were: 1) only have head circumference sheets to 36 months of age (n = 28); 2) the American Academy of Pediatrics does not recommend it (n = 3); and 3) the head stops growing at 36 months of age (n = 2). CONCLUSIONS Pediatricians and pediatric subspecialists need instruction on head circumference measurement in children from infancy through adolescence, and when indicated, in comparison with the head size of the same-sex parent. This measurement may be an effective and inexpensive assessment tool.