One of my clients recently entered the US on Visa Waiver. Visa Waiver is a nonimmigrant 90-day entry authorized by treaty with countries that have biometric passports, and no Consular Visa interview is required. She was very pregnant and gave birth to twins just a few days after being admitted. The current debate on the 14th Amendment that provides automatic US citizenship when born in the US raised my interest whether pregnancy could be a visa ineligibility.
Although there are no specific regulations prohibiting pregnant foreign nationals from entering the US entry is allowed or denied at the discretion of the admitting US Customs and Border Protection (CBP) Officer.
There is room for debate whether coming to the US for the purpose of childbirth is not a valid reason for travel, i.e., B visa or Visa Waiver entry.
Foreign nationals may have valid reasons for traveling to the US to give birth in the US, including family support and better medical care. There is room to argue that tourist visa applications should not be denied based solely on the notion that giving birth to a child is an impermissible activity under the Department of State B Visa regulations (provisions 9 FAM 41.31).
A recent statement by the US Consulate in Paris states:
"While it is clearly legal for a foreign national to give birth in the United States, COs [consular officers] are aware of widespread abuse of the US Medicaid system by pregnant foreign nationals traveling on B1/B2 visas. Pregnant applicants are therefore advised to tell the CO of their intent. This is both an issue of credibility and a control that allows the CO to ensure that the applicant has the means to pay for the birth and has taken appropriate steps to arrange for such payment, including any pre-natal and post-operative care required. The totality of circumstances are taken into account when applicants are pregnant and overall credibility is of primary concern to the CO."