Infant death among Ohio resident infants born at 32 to 41 weeks of gestation.

Objective: The aim of this study was to determine gestational age-specific, adjusted infant mortality rates for Ohio.

Study Design: Using a retrospective cohort design, all births and infant deaths from 2003-2005 were included in multivariable regression analyses. Variations in cause and timing of infant death were determined.

Results: Compared with births at 39 or 40 weeks, adjusted likelihood of infant death increased progressively between 38-32 weeks' gestational age. At later gestational ages, death was more likely caused by sudden infant death syndrome or intentional injury compared with congenital malformations and asphyxia or cerebral palsy at earlier gestational ages. Less mature infants tended to die earlier.

Conclusion: The current study confirms for Ohio and extends the findings of others that infant mortality risk is increased for births at late preterm and near-term gestational ages. Decisions to deliver before 39 weeks should consider increased likelihood of infant death that may be unrelated to fetal malformations or maternal illness.