According to new numbers released by the Population Reference Bureau (PRB), the number of women at risk for female genital mutilation has practically doubled in the last decade. The latest numbers suggest that there are more than a half a million girls and women in the United States that are either at risk of undergoing the procedure or have already undergone the procedure in the U.S. or during trips abroad. PRB estimates that number includes 166, 173 girls under the age of 18.

Newsweek reports:

Immigration to the U.S. from African and Middle Eastern countries—where the practice of FGM is a deeply entrenched cultural tradition—is the sole factor for the rise in numbers, says Mark Mather, a demographer at PRB who led the data analysis. There has not been an increase in the practice happening in the U.S. itself, he says.

Of importance, says Mather, is that these are estimates of the number of women and girls who are at risk of having FGM sometime in their life, or have already had it: "Not all of these women and girls have undergone the procedure, we're just trying to come up with our best estimate of potential risk," says Mather. "Given that we've seen a lot of new immigrants, especially from Africa, it's become a more important issue here in the U.S. and in Europe as well."

The Centers for Disease Control and Prevention is set to publish their own study on the issue in the next few months. Newsweek reports that they have "seen an unpublished draft" of the report, the findings of which are nearly identical to the PRB's.

According to Newsweek, the data also shows:

...California is the state with the largest number of at-risk women and girls, with 56,872, followed by New York, with 48,418, and Minnesota, with 44,293. In terms of cities in the U.S., New York, Washington and Minneapolis-St. Paul are the metropolitan areas with the largest numbers of at-risk women and girls.

Included in the data are girls at risk of being sent back to their family's origin country to undergo FGM—a practice widely known as "vacation cutting"—or having a traditional midwife or cutter sent to perform FGM in the U.S.

FGM has been illegal in the U.S. since 1996 and "vacation cutting" was outlawed in 2012.

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