Influence of nutrition on growth in premature infants: assessment by knemometry

Lower leg length measurements in 19 healthy preterm infants were obtained by knemometry to assess short term growth. Eight infants received fortified human milk and 11 infants commercially available preterm formulas. Two independent observers measured lower leg length in each infant daily during the study period, weight was measured daily with a neonatal scale. While weight gain showed linearity in all infants, lower leg length growth showed mini growth spurts of 5 +/- 1.7 days, growth periods of 20 +/- 11 days or both types of short term growth. The overall weight gain was 35 +/- 5.6 g/day in infants fed human milk and 33 +/- 7 g/day in infants fed preterm formula. The overall lower leg length growth velocity was 0.51 +/- 0.04 mm/day versus 0.54 +/- 0.09 mm/day, respectively. Both groups had comparable weight and length increments. No correlation existed between the type of nonlinear lower leg length growth (mini growth spurts versus growth periods) and the feedings received by the infants.