CASPER, Wyo. (AP) - More teen pregnancy and fewer mothers with health insurance are partly to blame for a 22 percent increase in the rate of premature births in Wyoming from 1995 to 2005.

The organization March of Dimes reports that more than 13 percent of babies born in Wyoming in 2005 were premature. The national rate was 12.7 percent in 2005, the most recent year of available data.

A premature birth is defined as any birth before 37 weeks of gestation.

In Wyoming, about 1 in 5 women of childbearing age are uninsured. Another possible contributor: About 1 in 4 Wyoming women of childbearing age are smokers.

March of Dimes says premature babies can have problems breathing, gaining weight, sleeping and developing at a normal pace.