Ratio of mid arm circumference to head circumference as a predictor of small for gestational age babies.

Birth weight (BW), mid-arm circumference (MAC), head circumference (HC) and MAC/HC ratio were evaluated in 845 term babies within 48 h of birth. MAC/HC ratio of less than 0.28 had a statistically significant sensitivity, specificity and predictive value (p less than 0.001) for identifying term small for gestational age babies. This ratio provides a simple, accurate and cheap way of screening SGA babies. This method may be employed for identification of SGA babies even by paramedical workers at community level. As with any other field index appropriate supervision and standardisation are essential for its usefulness.