Changes in weight, length, head circumference, and ponderal index at birth of healthy term newborns in nine cities in China during the period of rapid social development 1985-2005.

The changes in the anthropometric parameters at birth of healthy singleton term newborns in nine cities in China were analyzed by means of the data collected in three large-scale cross-sectional physical growth surveys in 1985, 1995, and 2005 (n=6660, 7109 and 6144). Between 1985 and 2005, average increases in body weight (BW), body length (BL), ponderal index (PI), and head circumference (HC) of newborns were statistically significant: 107g, 0.2cm, 0.6kg/m(3) and 0.4cm, respectively. The relative increase in BW was more than that in BL (3.4% vs 0.4%) in the last two decades, leading to an increase in PI. The distribution of birth size shifted slightly to the right, and the proportion of macrosomia increased from 3.2% in 1985 to 3.4% in 1995 and to 4.3% in 2005. The increases in BW and PI and the increase in rate of macrosomia are concerns from public health perspectives.