Differences in trends of postneonatal mortality by birthweight in upstate New York, 1968-1979

Area of Science:

• Neonatal and Perinatal Health
• Pediatric Mortality Studies
• Public Health Surveillance

Background:

• Infant mortality remains a critical public health concern.
• Understanding trends in postneonatal mortality is essential for targeted interventions.
• Birth weight is a significant determinant of infant survival.

Purpose of the Study:

• To analyze postneonatal mortality trends among neonatal survivors.
• To examine the age distribution of infant deaths by birth weight.
• To identify changes in postneonatal mortality over an 11-year period in upstate New York.

Main Methods:

• Retrospective cohort study analyzing birth and death records from upstate New York.
• Data collected for births occurring between 1968 and 1979.
• Postneonatal mortality rates calculated and stratified by birth weight categories.

Main Results:

• Postneonatal mortality rates increased for infants weighing 501-1500 grams.
• Infants weighing 1501-2000 grams experienced a mid-1970s increase, returning to 1968 levels.
• Postneonatal mortality declined for infants weighing 2001+ grams; however, the proportion of postneonatal deaths increased across all birth weights.

Conclusions:

• Specific birth weight groups, particularly those with very low birth weight, faced increasing postneonatal mortality risks.
• The rising proportion of postneonatal deaths suggests a potential shift in the timing of infant mortality.
• Findings highlight the need for continued monitoring and research into factors influencing postneonatal survival across different birth weight strata.