Expectant parents face a lot of decisions, from what to name the baby to childcare duties. But many Chinese families are adding another twist: Which country to give birth in.

The number of Chinese women giving birth in the U.S. more than doubled to about 10,000 in 2012, up from about 4,200 in 2008, according to CNN Money, which cited Chinese state media. While that's a small sliver of the estimated 16 million babies born in China every year, the boost represents a trend among well-heeled Chinese families who want to give their child the opportunity to secure a U.S. passport.

The trend hasn't only hit the U.S., with Hong Kong seeing a doubling of births to moms from mainland China in 2012, thanks in part to the former British colony's providing automatic rights to the mothers and their babies. While Hong Kong has since cracked down on the practice, so-called "birth tourism" isn't illegal in the U.S., and businesses in China have popped up to provide expectant mothers with travel packages to the U.S. for rates as high as $50,000, according to Foreign Policy magazine.

Get Breaking News Delivered to Your Inbox

For some Chinese mothers, traveling to the U.S. to give birth allows them to bypass China's one-child policy, CNN Money notes. Not every couple can have more than one child in China, despite an easing of the rules. It noted that one woman, a hairstylist named Miao Yu, spent $30,000 to give birth to her second child in the U.S.

The practice allows those children to claim American citizenship, which could provide Chinese families an escape route in case of unrest. It's more likely that the families are hoping to provide their children with opportunities, such as the visa-free entry to dozens of countries that an American passport provides. China Central Television undertook a "person on the street" survey and found that one-third had considered or will consider giving birth in another country, Foreign Policy noted.

The idea of giving birth in the U.S. even inspired a recent movie hit, with "Finding Mr. Right" following the fortunes of a pregnant unmarried Chinese woman who travels to Seattle to give birth and avoid the shame of an out-of-wedlock birth in her native country.

There is a downside for those Chinese families, if their children keep American passports after they become adults and start a career. The U.S. has a stringent law that requires its citizens to pay taxes no matter where they live, making it the only country to do so (other countries tax based on where the income is earned.) While the IRS doesn't tax up to almost $100,000 of foreign earnings, many expat American executives and even the mayor of London, Boris Johnson, have protested the rule, with Johnson calling it "absolutely outrageous."

It's not only Chinese families that are engaging in birth tourism, of course. Korean Air Lines "nut rage" executive Cho Hyun-ah sparked anger in her home country after giving birth to her twin sons in Hawaii, with some pointing out that it would enable them to avoid South Korea's compulsory military service.

Like the U.S., Canada is another developed country that provides citizenship to children born within its borders. That's sparked a rise in birth tourism there, as well, with some hospitals seeing a quadrupling in the numbers of foreign mothers giving birth in the last five years.