Infant Mortality Although Delaware’s infant mortality rate (IMR) was significantly higher than the national rate throughout most of the 1980s, Delaware followed the nation’s downward trend to a point where the U.S. and Delaware rates were very similar. The 1994-1998 time period signaled a reversal of this trend and Delaware’s rates rose steadily until 1998-2002, after which they have remained fairly stable, though significantly higher than the U.S. rates. IMRs for all three counties remained stable from 2000-2004 to 2001-2005. Sussex County’s IMR of 8.2 was the lowest of the three counties; Kent county’s IMR of 10 infant deaths per 1,000 live births was the highest. Overall, Wilmington has experienced the greatest decline in IMRs. Since 1989- 1993, Wilmington’s IMR has decreased 36 percent. From 2000-2004 to 2001-2005, the 5-yr infant mortality decreased very slightly due to a decrease in the white IMR (from 7.3 to 6.8); black IMRs increased from 16.1 to 17.1 during the same time period. As shown in the graph below, black infants experienced significantly higher mortality rates than white infants, and from 1989-1993 to 2001-2005, black IMRs were anywhere from 2.2 to 2.8 times that of white IMRs. Significant disparities existed between black non-Hispanic IMRs and each of the two other groups, white non-Hispanic and Hispanic. Black non-Hispanics had the highest IMR in all three time periods, and their rate of 16.4 deaths per 1,000 live births, was more than double the white non-Hispanic rate of 6.9 and the Hispanic rate of 7.2 Not only did IMRs vary between counties, but also between races within each county. Black IMRs were consistently higher than white IMRs in all three counties, and for every time period. To gauge the disparity between black and white IMRs, disparity ratios1 were used. However, as is shown in the graphs to the right, both the disparity ratio and the rate should be considered when examining the issue of infant mortality. In general, overall IMRs for each county were relatively unchanged from 2000- 2004 to 2001-2005. In New Castle County, rates for each of the two races also changed very little, and the disparity ratio remained stable at 2.4. In Kent County a decrease in the white rate paired with an increase in the black rate, caused a 70 percent increase in its disparity ratio, which rose from 1.5 to 2.2. Sussex County’s disparity ratio increased by 60 percent due to an increase in black IMRs and a decrease in white IMRs. At 3.5, Sussex County had the largest disparity ratio of the three counties. 1. Disparity ratios were calculated by dividing the black IMR by the white IMR; the resulting number demonstrated the magnitude of difference between black and white. A significantly higher incidence of infant mortality occurred in plural births than in singleton births. The proportion of plural births increased 25.5 percent from 1992-1996 to 2000-2004; over the same time plural infant mortality rates increased 68 percent to a rate 6.7 times that of the singleton rate (50.3 versus 7.5 infant deaths per 1,000 live births in 2000-2004). Though infants born to uninsured mothers had IMRs two to three times higher than infants whose deliveries were paid for by Medicaid or private insurance, they only accounted for 2.6 percent of all live births in 2000-2004. Infants born to mothers who were privately insured accounted for 58 percent of all live births and their IMR has risen 52 percent since 1993-1997, to 7.9 deaths per 1,000 births in 2000-2004. The IMR for infants whose deliveries were paid for by Medicaid has fluctuated between 9.8 and 10.8 since 1993-1997. Birthweight and gestation are considered to be the most important predictors of infant health and mortality risk. Infants born too small or too early have a much greater risk of mortality than those who reach a normal birthweight (2500+ grams) or full-term gestation (37+ weeks). While the IMRs of white VLBW (<1500 grams) infants showed a large increase between 1993-1997 and 2000-2004, IMRs for white infants of MLBW (1500-2499 grams) and normal (2500+ grams) birthweight decreased. The IMRs of black infants increased for all birthweight categories, though the largest increase was seen in infants of normal birthweight. With the exception of moderately premature (32-36 weeks) infants, IMRs by gestational category look very similar to the graph above. IMRs for very premature (< 32 weeks) white infants and full-term (37+ weeks) black infants showed the greatest increases. Approximately 95 percent of all infant deaths occurred within the first six months of life, and 73 percent of all infant deaths occurred within the first 28 days of life. The graph below displays deaths by specific cause and the infant’s age classification at death, neonatal (<28 days) or postneonatal (28- 364 days). Disorders related to short gestation and fetal malnutrition accounted for the greatest number of infant deaths in 2001-2005; all of these deaths occurred in the neonatal period. Sudden infant death syndrome (SIDS) was the only one out of the top five causes of death that had the majority of deaths occurring in the postneonatal period, with a mean age at death of 82 days. 28 percent (12 out of 43) of the SIDS deaths were associated with co-sleeping with adults and/or sleeping on soft surfaces, such as couches and adult beds. During that same time period, there were 14 additional infant deaths, coded under a different cause of death, that were associated with co-sleeping and/or sleeping on a soft surface. In 2001-2005 the three leading causes of infant death were: Disorders related to short gestation and fetal malnutrition (21.2 percent of infant deaths), Congenital anomalies (13.1 percent of infant deaths), and Newborn affected by maternal complications of pregnancy (10 percent of infant deaths). While disorders related to short gestation and fetal malnutrition was the top cause of death for both black and white infants, the number 2 and 3 spots varied by race, as shown in the pie charts below. In the 1989-1993 time period, Hispanics accounted for approximately 3 percent of all live births and infant deaths, since that time the proportion of births to Hispanic mothers has been increasing. In the most recent five year period, 2001-2005, 12.4 percent of all live births were to Hispanic mothers, and 9.7 percent of all infant deaths were of Hispanic origin. The leading cause of death for infants of Hispanic origin was Disorders related to short gestation and low birthweight, not classified elsewhere, followed by All other conditions originating in the perinatal period, which includes labor and delivery complications, cardiovascular disorders, and bleeding disorders. Printed copies of tables, graphs, and charts can by obtained by contacting: Delaware Health Statistics Center Delaware Division of Public Health 417 Federal Street Dover, Delaware 19901 (302) 744-4541