Objective:

To evaluate the diagnostic agreement for low birth weight between Colombian estimated fetal weight tables and the international INTERGROWTH 21 tool within a Colombian population.

Materials and Methods:

Cross-sectional diagnostic concordance study; included newborns born between January 1 and December 31, 2019, in Manizales, Colombia. Sociodemographic factors were described, and low birth weight was defined as being below the 10th percentile for gestational age using both INTERGROWTH 21 and Colombian reference values. The prevalence of low birth weight was calculated for both tools, and Cohen’s kappa index was used to determine the level of agreement between them.

Results:

A total of 3,025 live births were included. The INTERGROWTH 21 tool classified 47% of the newborns as having low birth weight, while the national reference classified 32% as being at risk for low weight. The weighted kappa value for concordance was 0.68.

Conclusions:

The INTERGROWTH 21 tool tends to overestimate the diagnosis of low birth weight compared to local reference tables. Cohen’s kappa index of 0.687 indicates that there are differences that impede a “very good” level of diagnostic agreement between the two tools for defining low birth weight.