ABSTRACT
We compared assessment of gestational age by Dubowitz score with ultrasonic measurement
of the biparietal diameter (BPD), and then evaluated how infants were classified by
these methods as small-for-gestational age (SGA), and as pre- or post-term births.
BPD gestational age was assessed at week 17 to 20 of pregnancy while the Dubowitz
scoring was done at birth. “Limits of agreement” between methods and kappa values
were calculated and used to evaluate agreement. Among 839 included infants, there
was moderate agreement between Dubowitz score and BPD (limits of agreement; -2.3;
+2.1 weeks; weighted kappa: 0.46) in the assessment of gestational age. Agreement
between Dubowitz score and BPD in the classification of SGA (kappa: 0.75, 95% confidence
interval [Cl]: 0.69-0.81) and preterm infants (kappa: 0.68, 95% Cl: 0.56-0.80) was
good, whereas agreement on infants born post-term was no better than chance (kappa:
0.14, 95% Cl: -0.02 -+0.30). We conclude that despite moderate agreement between Dubowitz
score and BPD in the assessment of gestational age, agreement in the classification
of low-birth-weight infants as SGA and as premature births was good.
Keywords
Gestational age assessment - kappa statistics - newborn infants - small-for-gestational
age
