Diagnostic value of newborn foot length to predict gestational age
Abstract: Identification of gestational age, especially
within 48 hours of birth, is crucial for newborns, as the earlier preterm
status is detected, the earlier the child can receive optimal management.
Newborn foot length is an anthropometric measurement which is easy to perform,
inexpensive, and potentially efficient for predicting gestational age.
Objective To analyze the
diagnostic value of newborn foot length in predicting gestational age.
Methods This diagnostic study was
performed between October 2016 and February 2017 in the High Care Unit of
Neonates at Dr. Moewardi General Hospital, Surakarta. A total of 152 newborns
were consecutively selected and underwent right foot length measurements before
96 hours of age. The correlation between newborn foot length to classify as
full term and gestational age was analyzed with Spearman’s correlation test
because of non-normal data distribution. The cut-off point of newborn foot
length was calculated by receiver operating characteristic (ROC) curve and diagnostic
values of newborn foot length were analyzed by 2 x 2 table with SPSS 21.0
software.
Results There were no significant differences between male and female
newborns in terms of gestational age, birth weight, choronological age, and
newborn foot length (P>0.05). Newborn foot length and gestational age had a
significant correlation (r=0.53; P=0.000). The optimal cut-off newborn foot
length to predict full term status was 7.1 cm. Newborn foot length below 7.1 cm
had sensitivity 75%, specificity 98%, positive predictive value 94.3%, negative
predictive value 90.6%, positive likelihood ratio 40.5, negative likelihood
ratio 0.25, and post-test probability 94.29%, to predict preterm status in
newborns.
Conclusion Newborn foot length can
be used to predict gestational age, especially for the purpose of
differentiating between preterm and full term newborns.
Keywords: preterm; foot
length; gestational age; newborn
Author: Mutia Farah Fawziah,
Bambang Soebagyo, Dwi Hidayah
Journal Code: jpkedokterangg170181
