Friday, August 29, 2008

HEALTH NEWS: US Infant Mortality Rates Stall

(previously published here at

A CDC statistical report says a nearly decadelong decline in rates of infant deaths has stalled, with records showing little change in the last three years. However, premature births are directly associated to increased deaths, especially for "non-Hispanic black women."

The CDC defines this category of people as having African ancestry and no maternal ancestors of Hispanic descent.

The overall rate, unrelated to premature births, showed very little change from 2004 to 2005, with 6.78 deaths per 1,000 live births versus 6.86 deaths. The report was released Wednesday by the CDC's division of vital statistics, which collects data on U.S. rates of infant mortality, birth and death.

Preterm-related infant deaths rose overall from 34.6 percent to 36.5 percent between 2000 and 2005. For non-Hispanic black women, babies were 3.4 times more likely to die from preterm-related causes than were non-Hispanic white women. Per 1,000 live births of black infants, 13.26 died in 2005, a rate that is on par with some developing countries.

Within the Hispanic spectrum (Mexican, Puerto Rican, Cuban, and Central and South American), preterm-related mortality rates were highest for Puerto Rican mothers, 87 percent more than in non-Hispanic white mothers. They were lowest for low-birth-weight infants with mothers of Mexican descent.

"We continue to have persistent and very large disparities by race and ethnicity," said lead author T.J. Mathews, a demographer with the National Center for Health Statistics. While connections between race and higher infant mortality are not certain, these are issues being discussed.

Extremely early births (before 32 weeks gestation) and preterm births (before 37 weeks) are a large factor in infant mortality, according to the report. "Rates [of infant death] are higher in that first day or first week than later on in the post-neonatal period," Mr. Mathews said.

The report also notes that there has been a steady increase in the number of preterm and low-birth-weight births since the mid-1980s, in part due to a rise in multiple births, more frequent use of fertility treatments and an increase in the number of C-sections and early induced labor.

Causing 44 percent of all infant deaths in 2005 were birth defects, low birth weight and sudden infant death syndrome (SIDS). Mortality rates were also higher for infants born in multiple deliveries (twins, triplets or more), and to mothers either born in the U.S. (perhaps due to fewer support systems than outside the U.S.) or who were unmarried.

Maternal age and level of education also had some connection with infant mortality rates, with the fewest deaths occurring with women giving birth in their 20s and 30s, and with 16 or more years of schooling. In addition, infant mortality rates were higher among boys than girls.

Mothers of Mexican descent had the lowest rates of low-birth-weight infants (6.5 percent), while Asian or Pacific Islander moms had the lowest death rates among preterm births (10.7 percent).

On the other hand, compared with non-Hispanic white mothers, SIDS rates were highest for babies with American Indian or Alaskan Native mothers, as well as with non-Hispanic black mothers (2.0 times and 1.8 times higher). SIDS rates were lowest for Mexican mothers (48 percent), Asian and Pacific Islander mothers (57 percent), and Central or South American mothers (68 percent).

Heather J. Chin can be reached at

©The Evening Bulletin 2008

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