The number of babies born before 37 weeks gestation—between 34 and 36 weeks—grew 20% between 1990 and 2006, a trend that carries serious implications for public health and the nation's caregivers, according to a new federal report.
Babies born during this "late-preterm" period "are less healthy than infants born later in pregnancy," according to the Centers for Disease Control and Prevention report.
"These infants are developmentally and physiologically immature" and "are more likely than term babies to suffer complications at birth, such as respiratory distress, to require intensive and prolonged hospitalizations, to incur higher medical costs, to die within the first year of life, and to suffer brain injury that can result in long-term neurodevelopmental problems."
The agency said that while it's unclear exactly what has caused this increase, it implies that the way labor and delivery are managed may be influential. For example, it said:
The increase in births within 34 to 36 weeks gestation also was not offset by a decline in births delivered earlier than 34 weeks, the agency said.
To quantify the problem, the CDC said that about 50,000 more babies were born in this three-week period in 2006 than in 1990. "On average, more than 900 late-preterm babies are born every day in the United States, or a total of one-third of 1 million infants, (333,461)."
The report found that while late-preterm births increased throughout the country in this period they increased by 20% or more in more than half of all states. The District of Columbia, meanwhile, saw a 16% decrease.
West Virginia leads the increase, with 53% more late-preterm births in 2005-2006 compared with 1990-1991. West Virginia is followed by Maine, 44%; Massachusetts, 43%; Kentucky, 42%; Montana, 40%; and Kentucky, 42%.
States with the least increases include California and Connecticut, 4%; Arkansas, 9%; and New Jersey, Virginia, and North Carolina, 10%.