Normal anterior fontanelle sizes in newborn Igbo babies in south-eastern Nigeria

Abstract

Background. Several factors, including gestational age (GA), gender, race and geographical/regional area, contribute to variations in the size of the anterior fontanelle (AF). While the impact of GA and gender are clearly established, the influences of region and ethnicity vary in the published literature. Objectives. To assess AF sizes in normal newborn Igbo babies in south-eastern Nigeria, establish baseline values for our population, and evaluate the relationship of our findings to some factors reported to affect AF size. Methods. AF size was measured in 269 healthy term newborn babies using the method proposed by Popich and Smith and modified by Faix. Measurements were taken 24 - 48 hours after birth. Results. The mean AF size was 2.97 cm (± standard deviation (SD) 0.71, range 2.0 - 4.8). Female babies had slightly larger anterior fontanelles than males (2.98±0.75 cm v. 2.97±0.67 cm, respectively), although this was not statistically significant ( p >0.05). Size of the AF had no significant correlation with head circumference (Pearson correlation coefficient r =-0.01; p =0.89), birth weight ( r =-0.05; p =0.39) or length ( r =-0.00; p =0.99) of these term babies. Neither GA nor mode of delivery influenced AF size ( p >0.05). The mean anteroposterior dimension of the AF (3.22±0.82 cm) was significantly longer than the mean transverse dimension (2.71±0.65 cm) ( p <0.01). Conclusions. At term, AF size has no relationship to GA or such growth parameters as head circumference, birth weight and length. The mean AF size of 2.97±0.71 cm obtained in this study is recommended for use in assessing term Igbo newborns.