The Center for Immigration Studies has released a new report that tracks the number of children born to foreign nationals in the United States, as well as the extent of what could be called “birth tourism.” The numbers are worrisome.

Using federal statistics for the second half of 2016 and the first half of 2017, the latest reliable data available, CIS estimates that 39,000 babies were born to foreign students, guest workers, and others on long-term temporary visas. There were an additional 33,000 births to tourists. This is in addition to the estimated 300,000 children born in the U.S. each year to illegal immigrants.

Birth tourism is the name applied to the phenomenon in which foreign women come to the U.S. specifically to give birth so that their child can automatically become a U.S. citizen. These women arrive shortly before their due date, give birth, then return to their country of origin once the child’s citizenship paperwork and passports are processed.

In some cases, these women stay with relatives in the U.S., but there are also birth-tourism services that provide living quarters and assistance in processing paperwork and taking care of the newborns until their births are registered with the state. Having a place to live temporarily in the U.S. allows the mothers to provide a valid domestic address with which to receive the citizenship paperwork before returning to their home countries.

The methodology of the CIS report is based on numbers obtained by the Census Bureau’s American Community Survey. The 2017 survey found that 854,896 foreign-born women had a child in the last 12 months. This was compared to a similar question asked by the Centers for Disease Control, which reported 897,223 births. CIS estimated down the difference by 35% to reflect the number of foreign-born women who were U.S. citizens.

The estimate of 33,000 births is in line with a previous study conducted by CIS in 2012, which found 36,000 birth tourists for that 12-month period.

CIS points out that its numbers are not gospel truth and therefore subject to statistical caveats. There is no agency that verifies addresses provided to states by parents on birth certificate records. The CIS is relying on Census Bureau information that contains its own margins of error, and from the CDC, which defines foreign-born people differently than the Census Bureau. Additionally, there are frequent undercounts in dealing with data that is reported on foreign-born individuals in the U.S., to say nothing about tracking the activity of illegal immigrants.

Just the same, Steven Camarota, director of research at CIS, points out, “Our analysis makes clear that the number of children born to visitors is not trivial; and over time the numbers are substantial.”

The scope of birth tourism and the sheer number of babies born in the U.S. to noncitizens should force a sincere review of the 14th Amendment’s clause that has come to be referred to as birthright citizenship. Open-border advocates have pushed the interpretation to mean that any child born in the U.S. is automatically a U.S. citizen, even if their parents are not citizens, don’t intend to become citizens, or are just conveniently passing through the U.S. in the weeks surrounding the pregnant mother’s due date. That is not at all what the drafters of the 14th Amendment intended to be the outcome of the clause, and it’s time originalist interpretation and just plain sanity prevailed.