BACKGROUND:
Birthweight is correlated with neonatal health. Healthy neonates who are small or large for gestational age (SGA or LGA) may need extra attention, for instance for assessment of hypoglycaemia after birth. To classify a neonate as SGA or LGA, it is important to take into account factors with a physiological impact on fetal growth. Apart from fetal sex, maternal height is such a factor. The current Dutch birthweight chart only accounts for newborns’ sex.

OBJECTIVES:
Our objective was to develop the VeCaS birthweight chart customised for both newborn sex and maternal height and evaluate the effect on birthweight classification and to compare the performance with the current Dutch birthweight chart.

METHODS:
Data were extracted from records of 21 350 women with healthy pregnancies, registered anonymously in the VeCaS Database in the Netherlands (2012–2020). We used Hadlock's method to construct the VeCaS-birthweight chart.

RESULTS:
The VeCaS birthweight chart showed higher median birthweights for neonates born from taller mothers and lower median birthweights for shorter mothers. At a gestational age of 40 weeks, this difference could be over 400g. Using the p10 and p90 as cut-offs, 7.0% of all newborns were reclassified from SGA or LGA to adequate for gestational age or vice versa, especially among shorter or taller women. The VeCaS birthweight chart showed an even distribution of SGA and LGA prevalences across maternal height categories.

CONCLUSIONS:
The VeCaS-birthweight chart optimizes birth weight classification. Our future aim is national implementation in the Netherlands. This will be prepared in 2026. Implementation will be evaluated in a national study.

KEY MESSAGE:
A birth weight chart that corrects for maternal height is easy to construct and helps to correctly identify neonates that are SGA or LGA. This helps to personalize postnatal care. Association strengthening 1 (including three-minute presentation competition)