Alaska Native and American Indian women living in the nation's urban centers are more than twice as likely to experience nonconsenting intercourse in their first sexual encounter, a new study shows. The report released Wednesday also shows that a third of urban indigenous women surveyed chose sterilization as a form of birth control.

The study was conducted by the Urban Indian Health Institute in Seattle on data collected in the 2002 edition of the National Survey of Family Growth, which looks at U.S. populations between the reproductive ages of 15 and 44.

Of the 7,643 women surveyed in the 2002 study, health institute researchers focused comparisons between 299 urban indigenous women and 3,173 non-Hispanic whites.

Researchers say their study is the first to examine the data for this subject.