Last month, the U.S. received a set of grades from the March of Dimes, the nation's leading organization committed to preventing preterm births, that were nothing short of horrible.
The report card on premature births compared preterm birth rates with national objectives. Overall, the nation received a D. Not a single state merited an A, and only one, Vermont, earned a B. Eighteen states and Puerto Rico and Washington, D.C., received an F, and California squeaked by with a C.
Given recent trends, it's unlikely that these grades will improve any time soon. Rates of preterm birth in the U.S. have been steadily increasing for years. In 2000, 11.6% of infants were born prematurely. In 2005, the most recent year for which statistics are available, this figure had grown to 12.7%.
The consequences of premature birth can be serious. Premature infants are at greater risk of dying during their first year of life than full-term infants. They often suffer from breathing and feeding problems and are at risk for intracranial hemorrhage (bleeding in the brain) and potentially life-threatening gastrointestinal problems. Their immature immune systems leave them susceptible to serious infections such as pneumonia and meningitis.
There are long-term problems associated with prematurity as well, such as cerebral palsy and vision and hearing loss. Children born prematurely also frequently suffer from learning and behavioral difficulties.
Experts in maternal and fetal health are working to identify the underlying causes of this increase in premature births. It appears that a variety of factors are at play.
Births between 34 and 36 weeks of gestation, or the late-preterm period, have increased most dramatically (a full-term birth takes place at 40 weeks). Late-preterm births now constitute 72% of all preterm births, according to the federal Centers for Disease Control and Prevention.
The fact that women are having babies at an older age is thought to contribute to this increase. "When they do get pregnant, women who are well into their 30s are more likely to incur all of the problems associated with pregnancy -- including prematurity," says Dr. Alan Fleischman, medical director for the March of Dimes.
The use of in vitro fertilization and other types of assisted reproductive technology also plays a role. More than half of all pregnancies conceived with assisted reproductive technology result in multiple births, dramatically increasing the risk of prematurity. Roughly half of all twin pregnancies deliver before 37 weeks and only 1 in 10 triplet pregnancies progress to term.
