Comparison of two fetal growth curves in screening for high-risk neonates

The International Statistical Classification of Diseases and Related Health Problems (ICD-10) defines the 10th percentiles on the fetal growth curve as the cutoff point for light- and small-for-gestational-age infants, instead of the mean body weight −1.5 standard deviation (SD) on the fetal growth curve, which has been used in Japan since 1983. Data on a 5260 sample of term neonates who were born during the 30-month period between January 1993 and June 1995 were obtained. The clinical usefulness of the 10th percentiles and mean bodyweight −1.5 SD cutoff on the fetal growth curve as screening criteria for high-risk neonates of light- and small-for-gestational-age infants was evaluated. There was a statistically significant higher morbidity rate among the neonates whose birthweight was below mean bodyweight −1.5 SD than for those whose birthweight was below the 10th percentile cut off. But there was no significant difference between the morbidity rate of neonates whose birthweight was between mean bodyweight −1.5 SD and the 10th percentile cutoff and the morbidity rate of neonates whose birthweight was above the 10th percentile cutoff. Therefore, mean bodyweight −1.5 SD on the fetal growth curve is a more effective means of screening for high-risk light- and small-for-gestational-age infants than the 10th percentile cutoff on the fetal growth curve.