Use of Perinatal Periods of Risk (PPOR) to investigate disparities in Mississippi feto-infant mortality

Background: Mississippi (MS) has the highest infant mortality rate (10.6 for 2004-2006) of the 50 US states. Evaluation of fetal deaths is needed to fully develop prevention efforts. Regional and racial influence on feto-infant mortality in MS was analyzed.

Methods: PPOR utilizes age at death, birth weight, gestational age and fetal death to create a matrix of risk factor influence on feto-infant mortality. The PPOR method was applied to MS 2003-2007 fetal and infant linked birth-death vital records, stratified by race and MSDH districts. An internal reference group was used to calculate excess mortality in the nine districts by race.

Results: Overall, MS 2003-2007 feto-infant mortality rate was 12.0/1000 fetal deaths + live births (district range 9.8-15.8/1000); black and white rates differed at 16.5/1000 and 8.3/1000, respectively. Black rates ranged from 15.3/1000 in the Gulf Coast District 9 to 17.7/1000 in Northwest MS District 3. White rates ranged from 7.1/1000 in District 4 (East Central MS) to 9.7/1000 in District 3. The primary characteristic associated with excess deaths was maternal health/prematurity for blacks (average=60%, district range=51-78%) and infant health for whites (average=52%, district range=3-83%); the secondary characteristic most associated with excess deaths was infant health for blacks (average=23%, district range=12-32%) and maternal health/prematurity for whites (average=24%, district range=0-59%).

Conclusion: Efforts are needed to decrease overall feto-infant mortality in MS, to reduce the racial disparity in rates, and to minimize rate differences across MSDH health districts. These efforts should focus on improved maternal health, reduced prematurity and improved infant health.