In newborns, measurements of head circumference (HC) provide an indirect method of estimating head growth during the intrauterine and neonatal periods and during the first years of life. Head size reflects the growth of the brain and has been associated with body size, brain malformations, or merely be familial factors 1 . Dobbing, in 1974 2 , emphasized that brain growth does not occur in a linear and symmetrical fashion but is, instead, characterized by periods of increased cell growth. The human brain experiences two growth spurts. The initial growth spurt occurs from 12 to 18 weeks of gestation and is characterized by neuronal multiplication. The second growth spurt begins at 28 weeks of gestation and extends through birth until the third year of life. This growth is considered the major period of growth of the brain. During these growth spurt phases, the brain is more vulnerable and susceptible to the presence of both internal and external factors that can affect brain and body growth. Davies 3 argued that HC is more influenced by genetic factors than by weight and height and that it is less susceptible to maternal factors, such as diabetes, multipara, prior abortions, hypertension, malnutrition, or placental anomalies.Several studies have investigated HC in newborns and infants and correlated them with maternal, placental, and fetal factors 4 . In fact, previous studies 5 have reported correlations between HC and other anthropometric measurements or gestational age (GA). Up until now, few research groups in Brazil have studied HC or its correlation with GA and gender 6 . Therefore, the aim of this study was to revisit newborn HC Universidade Federal do Rio Grande do Norte, Departamento de Pediatria, Programa de Pós-Graduação em Ciências da Saúde, Natal RN, Brasil.
ABSTRACTObjective: To revisit the head circumference (HC) of newborns in public and private maternity hospitals; to correlate our findings with the gestational age, gender, and type of delivery; and build and validate graphs and curves. Methods: This was a prospective study performed on healthy newborns. Differences in HC were analyzed as a function of gestational age, gender, the healthcare system and the type of delivery.Smoothed percentile curves were created using the least mean squares method. Results: Of the included newborns, 697 were born in private maternity hospitals and 2,150 were born in public maternity hospitals. In all, 839 were born by vaginal delivery, and 1,311 were born by cesarean delivery. At 37 to 42 weeks of gestation, male newborns had a larger HC than females. Infants born in private maternity and those born by cesarean delivery had a larger HC. Conclusion: An important result of the present study is that our analyses allowed us to generate curves and statistically-validated graphs that can be used in clinical neonatal practice.Keywords: neonatal head circumference; gestational age; gender; public and private maternity; newborn. Importante consequência deste estudo foi que os resultados permitiram a criação de curvas e g...