Per the Department of Homeland Security (DHS) Office of Immigration Statistics (OIS), I-94 non immigrant admissions can be sub divided into three categories
Non-resident,
Short-term resident, and
Expected long-term resident
The word “resident” should not be meant as “lawful permanent resident” of the US. It is mentioned only as an easy short-hand. The “non-resident” non-immigrant classification generally includes visitors for business or pleasure (tourists). They are generally authorized to remain no longer than six months. However, they can apply for extensions to stay an additional period of time. Due to this short stay, childbirths in this classification might be relatively low.
The “short-term resident” non-immigrant classification consists of trainees, students, exchange visitors, treaty traders and investors, intra-company transferees, and other types of non-immigrants who probably will be in the US for a longer period. Thus chances of them give birth to a child while physically present in the US are more.
Non-Resident Non-Immigrants: Per OIS report, 47.3 percent of the total “non-resident” non-immigrant admissions are women. The estimate figure is 4,555,942 female admissions for that non-immigrant category in 2009. An estimated 3,890,774 female tourists are in the child-bearing age.
The US currently does not have a formal exit recording system that would provide data on how many of these visitors are likely to remain in the US long enough to have a child, but in the past DHS researched the travel patterns of temporary visitors through the
I-94 arrival/departure forms. Per their report, most foreign tourists stay for a short period of about two weeks or less, but a significant number stay longer. The OIS departure data suggests that about 20 percent of tourists are here for three months or longer, a period that would provide the opportunity for a pregnant visitor to give birth and recover. It roughly estimates that about 780,000 women are legally present visiting here long enough to have a child.
Per the US Census data, in 2009, 5 percent of all foreign national women aged 18 to 35 who arrived within the last year reported giving birth during the year. It could well mean as many as 39,000 births annually to women who have arrived as tourists.
Short-Term Resident Non-Immigrants: Using the same principle as was used above with “non-resident” non-immigrants, we can arrive at a figure of 770,452 admissions of women in the specified age range in 2009. Artists, entertainers, athletes, and their entourages tend to make shorter visits. They comprise 5 percent of short-term resident admissions, so the figure can be reduced to 732,000.
The number of admissions is not the same as the number of individuals as some tend to come and go many times during the year. Since the average length of time before departure and return is six months at a time, it simply means that the average visitor in this classification will have two admissions per year. So the number of individual visitors can be somewhere close to half the number of admissions. So the estimated population of short-term resident women of child-bearing age can be estimated at 366,000. Using the 5 percent birth rate, we can roughly say that 18,300 children might have accrued
US Citizenship at birth for this non-immigrant category.
Per the Congressional Budget Office, “The total number of [non-immigrant] admissions in 2009 includes approximately 126 million admissions of Canadians and Mexicans who can enter the US without a visa and who need not have to fill out an Arrival/Departure Record (an I-94 form) when they enter. This number includes Canadian nationals traveling for business or tourism purposes and certain Mexican nationals with Border Crossing Cards.