Serial Head Circumference Measurements may help classify Microcephaly

In a recent study found the significance of monitoring newborns' head circumference (HC) not only at birth but also on their third day of life (DOL3). The findings published in the BMC Pediatrics have important implications for the diagnosis of microcephaly, reveal that measuring the maximum occipitofrontal circumference only once at birth or within 24 hours after birth may lead to misclassifications.

The study included 1131 live births with a gestational age of more than 27 weeks. Trained personnel used non-elastic tape measures to record HC measurements at birth or within the first 24 hours and again on DOL3 before the newborns were discharged. The World Health Organization (WHO) and Fenton Growth Charts served as reference ranges for interpreting the data for full-term and preterm neonates, respectively.

Paired sample t-test analyses demonstrated a statistically significant increase in HC when measured on DOL3 compared to measurements taken at birth or within the first 24 hours. On average, there was a 0.17 cm increase, emphasizing the need for ongoing monitoring during the critical early days of life.

Furthermore, 32 newborns initially fell below the third percentile (< P3) for HC at birth. However, 25 of these infants exhibited HC measurements equal to or above the third percentile on DOL3. This suggests that classifying microcephaly based solely on initial measurements may be misleading.

The study also examined factors associated with increased HC on DOL3. Newborns whose mothers experienced labor pains showed an average HC increase of 0.31 cm at DOL3. Additionally, infants who were symmetrically or asymmetrically small-for-gestational age (SGA) had significantly increased HC on DOL3, with average increases of 0.59 cm and 0.37 cm, respectively. Parity and gestational age, however, did not show a significant association with HC changes.

The study underscores the importance of serial HC measurements on DOL3 or before a newborn's discharge. These findings could have far-reaching implications for the early detection and classification of congenital microcephaly, ensuring that infants with this condition receive timely and appropriate care. 

Reference:

Sengasai, C., Chokephaibulkit, K., Plipat, N., & Wongsiridej, P. (2023). Serial head circumference measurements should be used to classify congenital microcephaly. In BMC Pediatrics (Vol. 23, Issue 1). Springer Science and Business Media LLC. https://doi.org/10.1186/s12887-023-04315-4