[Weight indices during the first 18 months of life in low birthweight infants]

A prospective study was carried out among 190 low birthweight neonates (less than 2,500 g) in order to assess their ratio of total body fat by 2 adiposity indices: Weight/Height3 (W/H3) at birth and Weight/Height2 (W/H2) subsequently. Adequate for gestational age (AGA) girls with weight indices (W/H3) above the 10th percentile (AGA/I+) had a lower height than AGA/I- girls on the 6th (p less than 0.01) and 9th (p less than 0.05) months of corrected chronological ages. Mean weight and height of small for gestational age (SGA) neonates with weight indices (W/H3) lower than the 10th percentile (SGA/I-) were similar to the SGA/I+ as soon as 3 months of corrected chronological age. SGA/I+ infants experienced a progressive increase in low weight indices (W/H2) until 15-18 months without significant differences with SGA/I- at 3, 6, 9 months of corrected chronological age. Meanwhile, low indices (W/H2) were more frequently observed in SGA/I- at 15-18 months. Thus the early characteristics in weight indices disclose a lower ratio of body fat in SGA infants than in normal children, at least up to age 15-18 months.