[Infant mortality from birth defects in Costa Rica, 1981-2010]

Identify trends for different types of birth defects and their impact on infant (IMR) and neonatal (NMR) mortality rates in Costa Rica from 1981 to 2010.

Infant, neonatal, and postneonatal mortality trends were analyzed, using data from the Central American Population Center, which uses the International Classification of Diseases, versions 9 and 10, to classify causes of death. For each group of birth defects, a Poisson log-linear regression model was constructed. IMR and NMR, relative risk, and 95% confidence intervals (95%CI) were calculated for the three decades (1981-1990, 1991-2000, and 2001-2010). Estimates were compared using Wald chi square.

Comparison of the 1980s and the 2000s found a significant decrease in NMR and IMR from birth defects in these decades, from 2.37 (95%CI: 2.26-2.48) to 2.13 (2.03-2.23) and from 4.13 (3.99-4.27) to 3.18 (3.05-3.31), respectively. Reduction in IMR was significant for birth defect groups for nervous, digestive, and circulatory systems. There was also a significant drop in NMR for nervous and digestive system groups. All other groups experienced a significant increase or no change.

IMR and NMR from birth defects have decreased, although these rates have increased proportionately due to a greater decline in other causes. This reduction is much smaller for neonatal mortality. Primary prevention and neonatal care of birth defects should be strengthened.