Contribution of birth defects to infant mortality in the United States.
BACKGROUND
While overall infant mortality rates (IMR) have declined over the past several decades, birth defects have remained the leading cause of infant death in the United States. To illustrate how this leading cause of infant mortality impacts subgroups within the US population a descriptive analysis of the contribution of birth defects to infant mortality at the national and state level was conducted.


METHODS
Descriptive analyses of birth defects-specific IMRs and proportionate infant mortality due to birth defects were conducted for the US using 1999 mortality data from the National Center for Health Statistics. In 1999, the change to ICD-10 impacted how cause-specific mortality rates were coded. Aggregated 1995-1998 state- birth defects infant death statistics were used for state comparisons.


RESULTS
In 1999, birth defects accounted for nearly 1 in 5 infant deaths in the US. Variation in birth defects-specific IMRs were observed by maternal race with black infants having the highest rates when compared with other race groups. However, among black infants prematurity/low birthweight was the leading cause of death, followed by birth defects. There is substantial variation in state-specific birth defects IMRs and the state-specific proportion of infant deaths due to birth defects.


CONCLUSIONS
Birth defects remain the leading cause of infant death in the United States, despite the changes that resulted in 1999 from an update in the coding of cause of death from ICD-9 to ICD-10. While birth defects-specific IMRs provide an overall picture of fatal birth defects and a gauge of the impact of life-threatening anomalies, they represent only a fraction of the impact of birth defects, missing those who survive past infancy and those birth defects related losses in the antepartum period. Expansion and support of effective birth defects monitoring systems in each state that include the full spectrum of perinatal outcomes must be a priority. However, paralleling these efforts, analyses of this leading cause of infant mortality provide critical insight into perinatal health and should continue, with appropriate adjustments for the 1999 classification changes.
Petrini
Joann
J
Perinatal Data Center, March of Dimes Birth Defects Foundation, National Office, 1275 Mamaroneck Avenue, White Plains, NY 10605, USA. jpetrini@modimes.org
Damus
Karla
K
Russell
Rebecca
R
Poschman
Karalee
K
Davidoff
Michael J
MJ
Mattison
Donald
D
D001741:Black or African American / Q000706:statistics & numerical data; D002423:Cause of Death; D000013:Congenital Abnormalities / Q000401:mortality; D005006:Ethnicity / Q000706:statistics & numerical data; D006801:Humans; D007223:Infant; D007226:Infant Mortality / Q000639:trends*; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D007234:Infant, Premature; D009309:National Center for Health Statistics, U.S.; D014481:United States / Q000453:epidemiology