A comprehensive new report shows nearly half a million American babies are born too soon each year.
According to the findings preterm babies are born at a higher rate in the United States than in 130 other countries.
Experts say one reason is that mothers here have children later in life which leads to multiple pregnancies.
The report defines preterm as any time before 37 weeks.
The earlier the baby is delivered, the greater the chance he or she will suffer lifelong health problems.
According to the study, 15 million babies are born preterm each year worldwide, of those, 1.1 million don't survive.