Secular changes in anthropometrical variables at birth: a local perspective Cambio secular de las variables antropométricas al nacer: una perspectiva local.

BACKGROUND: Anthropometrical measurements at birth are the result of the conditions during pregnancy, being an issue of current interest due to the reported relationship of birth weight with non communicable chronic diseases in adulthood. AIM: To study the change in anthropometrical measurements at birth, between the period 1974-1978 and the period 1995-1999, in two counties of Valparatso, Chile. MATERIAL AND METHODS: We collected information from the public health care system in a universe of 5,018 newborns of the two periods. RESULTS: When compared to 1974-1978, the period 1995-1999, showed 38% decrease in the number of deliveries, 0.7% decrease in parity, 1.4% decrease in pre-term deliveries and one year increase of mother's age. Likewise birth weight increased by 246 g in males and 210 g in females (p < 0.01). Birth length increased by 0.5 cm in males and 0.4 cm in females (p < 0.01). Low birth weight was reduced from 9 to 4.2% and length under -2 standard deviations from normal,