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

ABSTRACT

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 Valparaiso, 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 percent decrease in the number of deliveries, 0.7 percent decrease in parity, 1.4 percent 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 percent and length under -2 standard deviations from normal, also decreased from 5.4 to 1.5 percent (p <0.001). Conclusions: In the last 20 years, an improvement in anthropometrical measurements at birth was observed. Better conditions during pregnancy probably explain these changes