MID-ARM CIRCUMFERENCE/HEAD CIRCUMFERENCE RATIO (MAC/HC) AS AN F PROTEIN-CALORIE DEPRIVATION IN PRETERM INFANTS

Abstract

MAC/HC has been a useful anthropometric measure of malnutrition in older infants. Since standards have not been established for term or preterm neonates, we measured MAC/HC on day 3 of life in 104 term and 100 preterm infants (EGA 37.5-43 and 26-37 wks). A strong correlation between increasing gestational age and MAC/HC was found defining a standard curve y=.0056x + .066 (r=.85;p <.001). The MAC/HC of 25 preterm infants was then determined at 1 week intervals for 6±3 weeks (avg±SD). All infants were AGA, without hydrocephalus by ultrasound. 88% (22/25) of infants demonstrated a decrease in the MAC/HC during the first week postnatally and then fell to values below -2SD from the curve. By hospital discharge, 23/25 regained their birth HC percentile, but only 5 infants regained birth MAC/HC percentile. The mean caloric and protein intakes were significantly lower during weeks when MAC/HC decreased than when it increased (mean age at increase 2.9±1.1 wks). Caloric intake: 76±28 vs 104±24 Kcal/kg/d; p <.001; protein intake: 1.75±.8 vs 2.5±.8 gm/kg/d;p < .001. CONCLUSIONS: 1) The MAC/HC increases with gestational age. 2) Preterm infants fall off the standard curve on the basis of protein-calorie deprivation. 3) HC returns to its original percentile before MAC/HC demonstrating head-sparing at the expense of body mass in preterm infants. 4) Preterm infants remain below the MAC/HC standard curve at discharge despite presumably adequate weight gain and protein and calorie intake.