The Trump administration’s travel ban on people from seven Muslim-majority countries is likely to have far-reaching and unintended effects on the health of refugees, immigrants, and the American people.

Children needing lifesaving surgeries have already been affected.

In addition, the policies could affect researchers as well as thousands of foreign-born doctors.

That means people living in rural and low-income areas of the United States, where many foreign medical graduates provide care, may be particularly affected.

Shortly after the ban went into effect, shockwaves quickly spread throughout the healthcare system.

A 4-month-old Iranian girl traveling to the United States for lifesaving care for a congenital heart defect was among those prohibited from entering the country.

The girl and her mother eventually received special permission from the Department of Homeland Security to fly to Oregon, but the delay in undergoing surgery means she will face a much longer recovery.

A 1-year-old Syrian girl born without an eye and a seriously disfigured face was blocked, along with her family, from coming to the United States.

The girl had undergone two complex operations in Spain. The family had planned to resettle in the United States, and had already undergone all required security checks and interviews. Now they will need to find another country to take them in.

Experts are worried, in particular, about the fate of refugee children.

According to a recent United Nations report, children most in need of international emergency assistance come from five of the seven countries affected by the executive order — Iraq, Somalia, Sudan, Syria, and Yemen.

Adults were affected, too.

At San Francisco International Airport, an Iranian-born permanent resident of the United States — six months pregnant — was taken into custody by federal officials. She was held for hours before a judge ruled that green card holders were exempt from the executive order.

As the ban went into effect, hospitals around the country scrambled to help patients who had already planned to travel to the United States to receive care for serious medical conditions.

Read more: Half of Latinos unaware they have high cholesterol »

Ethnicity and health

Experts worry that the nature of the ban, which affects only Muslim-majority countries, increases the health risks for people of certain ethnicities.

“It puts immigrants, refugees, and basically anyone who may be perceived as being an immigrant or a refugee — including U.S. citizens — at risk of being perceived as a threat,” Jhumka Gupta, Sc.D., a public health professor at George Mason University, told Healthline.

These groups may be targeted with harassment or hate crimes.

But, said Gupta, just living in constant fear of being targeted or being perceived by others as a threat is associated with poor health outcomes.

Some research found that after the 9/11 terrorist attacks, Arab American adults who reported being abused or discriminated against because of their ethnicity showed increased psychological distress and poorer health status.

A 2006 study published in the journal Demography, found that women with Arabic-sounding names who gave birth in California during the six months after 9/11 had a higher risk of having a low birth weight or preterm baby, compared with women who delivered a year earlier.

“That shows how discrimination and the stress associated with it, as well as other mechanisms, can impact not only the individuals, but also future generations such as babies,” said Gupta.

The fate of the ban — which affects people from Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen — awaits a decision from the 9th U.S. Circuit Court of Appeals in San Francisco, which heard arguments for the case on Tuesday.

But damage to people’s health may have already been done.

“Even if the ban is lifted,” said Gupta, “the societal stigma is still there. So we have to deal with the health fallout of that.”

Read more: Being racist is bad for your health, and everyone else’s »

Doctors, other medical professionals impacted

Patients were not the only ones affected by the travel ban.

On Jan. 28, a Cleveland Clinic internal medicine resident from Sudan, on the way back to the United States, was deported from an airport in New York and sent to Saudi Arabia.

The doctor was in the United States on an H-1B visa for workers in "specialty occupations.”

Some doctors who are permanent residents of the United States were also detained as they tried to reenter the country.

These stories hint at one fact that many people may not realize — the United States is heavily dependent on foreign-born healthcare workers, including doctors, nurses, and home care aides.

About one quarter of the more than 800,000 physicians practicing in the United States are graduates of medical schools outside the country — as are 10 to 15 percent of trainees in doctor residency programs.

According to Andrea Clement Santiago, director of communications and media relations of The Medicus Firm, which recruits and places doctors in the United States, about 15,000 of those doctors are from the seven countries targeted in the travel ban.

That amounts to less than 2 percent of all doctors in the United States, but many foreign-trained doctors practice in rural and underserved areas .

More than one-quarter of the international medical graduates placed by The Medicus Firm practice in rural areas. Another quarter care for patients in large cities.

International medical graduates also account for a large proportion of those that practice certain specialties, including geriatric medicine and family medicine. And they provide care on par with graduates of American medical schools.

The executive order has created a great deal of uncertainty for foreign-trained medical personnel, which could harm the U.S. healthcare system well into the future.

“If the immigration policy is perceived to be unfair, or too tough,” said Santiago, “it may deter all international physicians, even those not from the targeted countries, from coming to the U.S. to practice.”

Read more: We may need an additional 90,000 doctors by 2025 »

Big impact of immigration policies

Other experts are concerned that the travel ban will harm medicine and science, including international work on diseases like Ebola.

The health IT industry, which draws heavily on highly skilled workers from outside the United States, could also be affected.

The American Medical Association (AMA) expressed concern about the impact of the immigration executive order on the nation’s healthcare system, in particular in rural and low-income areas.

The AMA has also shown support for a bipartisan bill that would protect young undocumented immigrants — often called “dreamers” — with Deferred Action for Childhood Arrivals (DACA). The bill would prevent them from deportation if they are doctors, medical students, or considering a career in medicine.

These immigrants are not affected by the current travel ban, but they could be deported later if the country tightens its immigration policies.

As the United States shuts its doors to refugees, immigrants, and other people in need of urgent medical care, other countries are opening theirs.

Last week in Ontario, Canada, Health Minister Eric Hoskins offered to provide healthcare for foreign-born children whose lifesaving surgeries have been cancelled in the United States due to the travel ban.

“This is a particular subset of children who require lifesaving surgery, so, absent that surgery, they will certainly die,” Hoskins told reporters at a press conference.