Relationship between the Anterior Fontanel Size and Occipito-frontal Circumference

Aims: To determine the relationship between Anterior Fontanel size (AF) and the Occipito-frontal circumference (OFC).

Study Design: A cross sectional and analytical study of Nigerian newborns and infants.

Place and Duration of Study: Post-natal ward, Special care Baby Unit and Well Infant Clinics of the University of Port Harcourt Teaching Hospital (UPTH) and Braithwaite Memorial Specialist Hospital (BMSH) Port Harcourt, Nigeria. Duration: 10 weeks, between October and December 2011.

Methodology: This is a Cross sectional observational and analytical study of 2895 subjects recruited serially at the Post-Natal Wards and Special Care Baby Unit (SCBU), University of Port Harcourt Teaching Hospital, (UPTH); and the Well Infant Clinics of UPTH and Braithwaite Memorial Specialist Hospital (BMSH), Port Harcourt, Nigeria. AF sizes were measured in newborns at birth and at 6, 10 and 14 weeks; 6, 9, 12, 18 and 24 months of age respectively using a modified version of Faix’s method.

Results: There were 1391 males and 1504 females giving a male: female (M:F) ratio of 1:1.1. AF sizes decreased significantly with increasing post-natal age, p < 0.001. The reverse was the case with OFC which increased significantly from birth to 24 months of age. A strong negative correlation was observed between AF size and OFC with increasing postnatal age.

Conclusion: A statistically significant negative correlation exists between AF size and OFC. This relationship can be represented mathematically by the formula: AF size = 14 - OFC (0.265).