U.S. among the worst for premature births

15 million babies are born prematurely each year around the globe. The United States fared badly in the first country-to-country comparison.

A study by the World Health Organization, Save the Children and hundreds of other child and health related organizations suggests a variety of factors are causing premature births in America.

Too many American women have health problems like obesity, diabetes, high blood pressure and smoking.{}{} Other factors include teen pregnancy or women older than 35 giving birth to twins or triplets after in vitro fertilization.{}

Another issue is many women who lack health insurance aren't seeing doctors early in their pregnancies, when problems like high blood pressure or genital infections can be treated.