Growth Standard for Newborns by Gestational Age

This standard specifies the indicators and methods for determining the physical growth status of a singleton newborn at birth with a gestational age of 24 to 42 weeks.

This standard is applicable to the group and individual evaluation of the physical growth status of a singleton newborn at birth with a gestational age of 24 to 42 weeks.

The following documents constitute the essential provisions of this standard through the normative references in the text. For the references dated, only their dated versions areapplies to this standard; for the references undated, their latest versions, including all amendments, are applicable to this standard.

WS/T 424 Anthropometric methods for population health monitoring

The following terms and definitions apply to this standard.

Total weight of the human body (bare weight).

[source: WS/T 424—2013, 3.4]

Length from the top of the head to the heel in the horizontal position.

[source: WS/T 424—2013, 3.2]

The circumference from the upper edge of the right flanking arch passing through the highest point of the occipital ridge.

[source: WS/T 424—2013, 3.5, with modification]

4.1 The gestational age was determined by the combination of the mother’s last menstrual period and the ultrasound examination in the first trimester. When the differencein gestational age between the two methods is less than 1 week, the last menstrual period of the mother shall prevail, and when the difference is more than 1 week, the ultrasound examination shall prevail.

4.2 The physical growth of newborns at birth was evaluated in Appendix A. Newborns with birth weight below the 10th percentile (P₁₀) for the same sex and gestational age were evaluated as small for gestational age; those above the 90th percentile (P₉₀) were evaluated as large for gestational age; those between P₁₀ and P₉₀ were evaluated as suitable for gestational age. Birth length and head circumference can be used as auxiliary indicators to comprehensively evaluate the physical growth of newborns at birth.

Weight, length, and head circumference of newborns are measured in accordance with WS/T 424.