Federal agents enter an upscale apartment complex, Tuesday in Irvine, Calif. Shortly after sunrise, federal agents swarmed the complex in the Orange County where authorities say a birth tourism business charged pregnant women $50,000 for lodging, food and transportation. The key draw for travelers is that the United States offers birthright citizenship. Jae C. Hong/AP hide caption

itoggle caption Jae C. Hong/AP

Maternal tourism, or birth tourism, is where paid operators arrange for pregnant women to give birth in the U.S. so their babies automatically become U.S. citizens.