Abstract 145

Breastfed (BF) infants display a trend to be heavier at birth and show z-scores for weight below international reference standards at 12 months (Pediatrics 1992; 89: 1035). To address this issue in an Italian infant population, we have compared the standardized birth anthropometrics of two groups of BF and formula-fed (FF) term infants born in our maternity ward. BF infants were included according to the WHO criteria (that is, exclusively breastfed for at least 4 months and then complemented during weaning with mother's milk). FF infants were exclusively formula-fed from birth. BF infants were further compared with the WHO "12-month breastfed pooled data set" (Bull WHO 1995; 73: 165). The weight-for-age (WA) and length-for-age (LA) z-scores were calculated by means of the ANTHRO software program (WHO reference data) at birth and 12 months. Twelve (8 males, 6 females) BF infants and 65 (35 M, 30 F) FF infants entered the inclusion criteria. BF subjects presented higher WA and WL z scores than FF at birth even after correction for parity and socioeconomic indicators (adjusted Δ WA z score = +0.99 for BF, P = 0.003). At 12 months the mean WA z score of the BF was around 0 (-0.04 ± 0.9, SD). Maternal factors may explain the association between higher birthweight and prolonged breastfeeding. Either the genetic background or different weaning schedules in Italy may result in less marked growth differences between BF and FF infants at the end of the first year of life.