Introduction: The U.S. infant mortality rate has been steadily declining since 2007. Although the downward trend has been notable in Alaska since 2006 when the rate was 6.9 infant deaths per 1000 live births, a dramatic drop in infant mortality occurred in 2010 and 2011 when the infant mortality rate fell to 3.8 infant deaths per 1000 live births during both years. The purpose of this study was to investigate the sudden decrease in fetal and infant mortality rates (FIMR) using the perinatal periods of risk (PPOR) method, an approach that has not been used previously in Alaska.
Methods: The study was conducted for 251 fetal and infant deaths in 2004-2006, 265 deaths in 2007-2009, and 129 deaths in 2010-2011. Data were stratified by Alaska Native (AN) and White maternal race and urban/rural residence.
Results: Among both urban and rural White women, the rate ratios (RR) for FIMRs between the earlier and later time periods were not significantly different. The postneonatal mortality rate (PNMR) among AN infants living in rural areas decreased significantly (RR 0.40; 95 % confidence interval 0.21-0.76) between 2007-2009 and 2010-2011. An unexplained increase in sudden unexplained infant death was noted in 2009, followed by a precipitous decrease in 2010-2011. No other unusual distribution of the cause specific mortality rates was observed.
Discussion: The decrease in the Alaska Native FIMR might have been due to focused efforts for preventing postneonatal sleep associated deaths. Education for prevention of sleep related deaths, particularly in rural communities, is necessary to maintain Alaska's low PNMR.
Keywords: Fetal and infant mortality; Perinatal periods of risk; SUID or sleep-related deaths.