Growth is usually evaluated by single measurements which reflect only that direction of growth. At birth the relationship between measurements is often considered as Rohrer's Ponderal index which describes weight in relation to length but can be misleading especially when considering premature infants. We propose that it is more appropriate to study the relationship of different anthropometric measurements to define normality and thereby create limits from which abnormalities in growth may be diagnosed. Weight, crown heel length, crown rump length and head circumference were measured in 305 healthy infants, at 26 42 gestational weeks to obtain reference values. Subischial leg length was calculated. A multivariate model was made which could be useful to distinguish the form and shape of an infant and to identify abnormalities in growth.