A statistical analysis by the National Center for Health Statistics (NCHS) released in early November 2009 shows a link between the large number of premature babies in the United States (which is twice the rate of some industrialized countries) and our infant mortality rate (which is as much as two-and-a-half times the rate of other Western countries).
An article about the study in The New York Times summarizes the link: "Premature infants in the United States are more likely to survive than those elsewhere. Yet they are still more likely to die than full-term babies, and the sheer numbers born prematurely in the United States—more than 540,000 per year—drive up infant mortality." The key to reducing infant mortality, therefore, is in reducing preterm labor.
In that article, the author of the NCHS study, Dr. Marian F. MacDorman, says there are several reasons the United States has such high rates of premature birth. For instance, the use of medically assisted reproduction methods like in vitro fertilization and ovary stimulation have lead to an increase of pregnant women carrying multiple fetuses—twins, triplets and more. These pregnancies are much more likely to result in premature births. Regulations in other countries are more restrictive about the number of embryos allowed to be implanted, so multiple births resulting from in vitro fertilization are uncommon.
Another reason cited for the high rate of premature babies is the common use of labor-inducing drugs and Caesarean sections, many of which are performed before babies are full term. Doctors are not supposed to induce or do a C-section unless it is medically necessary. "There sort of has been this shift in the culture. Fifteen or 20 years ago, if a woman had high blood pressure or diabetes, she would be put in the hospital, and they would try to wait it out. It was called expectant management," Dr. MacDorman told The New York Times . "Now I think there's more of a tendency to take the baby out early if there's any question at all."
Just weeks after the NCHS report was published, the March of Dimes issued its annual report card on efforts in the United States to reduce premature births—and almost no states did well. Vermont earned the best grade with a B, but the United States' overall grade was a D. The March of Dimes has a state-by-state breakdown of scores on their website.