Estimations of body surface area in newborns.

Aim: To explore the suitability of existing formulas to estimate the body surface area (BSA) of newborns when direct measurement of surface estimation is not practical.

Methods: In 589 term-newborns of normal weight and height, the five estimations (in cm2) were performed using four known BSA formulas by Boyd, Meban, Mosteller and Dubois, and the fifth arithmetic mean of these four formulas (BSA-Mean).

Results: BSA-Meban was most similar to the BSA-Mean with a mathematically perfect correlation and the least dissimilarity using Euclidean distance (ED), followed by the Mosteller estimate. The estimations by both Boyd and Dubois showed about a 5% deviation above and below the BSA-Mean, respectively, with a consistent dissimilarity using ED regardless of the same goodness of fit. The degree of deviation increased with the weight and decreased with height.

Conclusions: The formula by Meban is possibly the best BSA estimate for newborns among the existing formulas today, followed by the Mosteller formula. Due to either overestimation or underestimation, two formulas (Boyd and Dubois) are not recommended for surface estimation of newborns. A nomogram for surface estimation is needed for paediatric use especially with increasing preterm birth in modern society.