Diagnosis of impaired fetal growth in newborn infants
Miller, H.C.; Hassanein, K.
Pediatrics 48(4): 511-522
1971
ISSN/ISBN: 0031-4005 PMID: 5114738 Document Number: 36290
Crown to heel length (CH), head circumference (HC) and birthweight (BW) were measured for newborn infants whose gestational age was from 33 to 44 weeks. Birthweight and calculated gestational age (CGA) alone were not considered accurate enough to give a precise description of foetal growth impairment as birthweight was found to vary with sex, race, parity and CGA. The mean ratio of CH to HC was not thus affected and was calculated to be 1.45 plus or minus SD 0.045. Infants whose ratios were plus or minus 2 SD were considered to be disproportionate for their CGA. Ponderal indices (PI) were calculated for all infants using the formula PI = BW/(CH)3 X 100.A graph relating PI to CGA shows that the slope at the 3rd percentile is much less than that at the 97th percentile until 38 weeks CGA. Some infants were accumulating more soft tissue than others. After 38 weeks the PI was constant. Infants with PI above the 97th percentile were considered overweight; those below the 3rd percentile were considered malnourished. CH and HC were both affected by race, sex and parity. The use of CH:HC ratio and PI reduced the significance of these.