A study of correlation of foot length and new Ballard score in determining the gestational age of newborns

Abstract

Background: Gestational age (GA) estimation plays a vital role in obstetric, perinatal and neonatal care. Foot length (FL) measurement can serve as a simple, easy and cost effective parameter for estimating GA. The aim of this study was to determine correlation between foot length of new born and GA by new Ballard score and forming a percentile chart if a positive correlation was found.Methods: GA assessment of newborns born in our hospital was done by new Ballard score within 24 hours of life. FL was measured using vernier caliper. Neonates were classified as pre term, term and post term and also grouped as small for GA (SGA), appropriate for GA (AGA) and large for GA (LGA).Results: FL measurement was strongly correlating with GA assessment by new Ballard score, with overall correlation coefficient r=0.897 (p<0.001). FL increased as GA increased. Strong positive correlation was seen in pre term and term newborns. The cut-off foot lengths for identifying preterm and early preterm neonates were 73.14 mm (diagnostic accuracy 88.4%) and 68.49 mm (diagnostic accuracy 95.3%), respectively.Conclusions: Strong positive correlation of foot length with GA by new Ballard score was obtained and a percentile chart of foot length for each GA was formed, with mean and standard deviation. This can serve as a simple and quick tool, requiring less expertise for GA assessment.

Postnatal foot length in the estimation of gestational age in relation to intrauterine growth pattern among Nigerian neonates

“…This is supported by more recent studies which have demonstrated strong correlations between estimated gestational age and postnatal foot length. 11,12 Foetal growth is usually assessed by comparison of the weight, body length and OFC at birth with standards that define reference ranges at a spectrum of gestational ages, called the intrauterine growth charts. Lubchencho et al 13 developed the first intra-uterine growth charts involving only Caucasian neonates, and many more growth charts were developed in different parts of the world.…”

“…This is supported by more recent studies which have demonstrated strong correlations between estimated gestational age and postnatal foot length. 11 , 12 …”