[Neonatal mortality in a regional perinatal hospital in Merida, Yucatan, 1995-2004 I. Analysis of the gross, specific rates].

OBJECTIVE

To evaluate the neonatal mortality and the specific neonatal mortality rates by groups of birthweight and gestacional age, at the Ignacio García Téllez National Medical Center which is a reference tertiary perinatal center of the Social Security Mexican Institute for the Yucatan Peninsula, along the period of 1995-2004.

MATERIAL AND METHODS

A cohort of 46,297 live newborns was studied with birtweight of 500 grams or more, that were discharged between January 1st 1995 and December 31st 2004. Birthweight, gestational age, length of hospitalization, condition at discharge were captured in a data base. Triennial analysis of mortality was done.

RESULTS

The proportion of neonates with birthweight <2,500 g increased and 19% neonates <1,000 g 50%, the increment was 21% for preterm neonates, 46% for immature, and 40% for those extremely immature. The early neonatal mortality rate diminished from 7.0 to 6.9, the late mortality from 3.0 to 2.2, the neonatal from 10.0 to 9.2/1,000 live newborn, the survival increased 232% in neonates with birthweight between 500-749 g, 25% between 750-999 g, 5.8% between 1,000-1,249 g, 8.2% between 1,250-1,499 g. The neonatal mortality decreased 31.8% from the expected, because the adjusted neonatal mortality rate was 13.5 compared with the observed 9.2/1,000 live newborn.

CONCLUSIONS

There was a significant increase of the survival with lesser birthweight and gestational age, although it was not reflected in the brut neonatal mortality rate because there was an increase of the risk population.