More than a million babies worldwide die each year because they're born prematurely, according to a new March of Dimes report.
Babies are considered premature if they're born before 37 weeks gestation.
The March of Dimes says nearly 13-percent of babies born in the U.S. are preemies.
That percentage has risen by more than a third in the past 25 years because of an increase in elective C-sections and assisted reproduction.
IVF increases the chance of multiples, who are often born before they reach full-term.