“When Mexico sends its people, they’re not sending their best—they’re not sending you. They’re not sending you. They’re sending people that have lots of problems and they’re bringing those problems with us. They’re bringing drugs. They’re bringing crime. They’re rapists. And some, I assume, are good people.” This is how Donald Trump described Mexicans in his June 2015 announcement that he would be running for office.

Throughout the 2016 presidential campaign and since taking office, Trump has continued his derogatory and racist remarks toward immigrants. Shortly after moving into the White House, Trump took executive action to increase the detainment and deportation of migrants. At the same time, the president and his administration have moved to prohibit travel from certain countries in the Middle East, increase raids by Immigrations and Customs Enforcement (ICE), and ramp up security and enforcement at the U.S.-Mexico border.

New research suggests the harmful legislation and rhetoric of Trump’s campaign and early presidency is having a negative effect on pregnancies. Especially in light of Trump’s birthright citizenship comments, more attention should be paid to this issue.

Last week, researchers published the first study analyzing the impact of the 2016 U.S. presidential campaign and election on rates of preterm births (defined as giving birth before 37 weeks of gestation) in the Journal of Epidemiology and Community Health. Premature babies are at greater risk of developmental delays and problems with vision and hearing than their counterparts. In 2015, according to statistics from the Centers for Disease Control and Prevention, preterm birth and low birth weight accounted for 17 percent of infant deaths.

“We decided to focus on preterm birth because that’s where you would see a result most immediately,” said Dr. Nancy Krieger of the Harvard University School of Public Health, who led the study. “There may be other effects on health down the road, but preterm birth rates are where the impact would be first observed.”

The research team compared preterm birth rates in New York City during the period before the U.S. presidential nomination (measured from September 1, 2015 through July 31, 2016) to the post-inauguration period (measured from January 1, 2017 through August 31, 2017). The overall rate of preterm births rose from 7 percent before the nomination to 7.3 percent post-inauguration.

Increases in the rate of preterm births were particularly evident for births to Latina women, going from 7.7 percent before the nomination to 8.2 percent post-inauguration. The largest increase was among foreign-born Latina women with Mexican or Central American ancestry (7.2 percent before the nomination to 8.2 percent post-inauguration).

Additionally, the rate of preterm births among women born in Middle Eastern and North African countries rose from 5 percent to 5.4 percent, but since these groups represented merely a small portion of the study, the results were suggestive but not statistically significant.

Crucially, rates of preterm births among women born in the United States were not affected by the election.

Although Krieger, whose prior research has focused on the impact of Jim Crow and segregation on health, acknowledges that there are other factors that affect preterm birth rates, the design of the study was meant to isolate the impact of the election. The team’s goal was to understand what impact being politically targeted has on an individual’s health. As Krieger explained, “It’s relevant because preterm birth impacts both the mother and the next generation.”

Numerous studies have found that immigrants to the United States arrive with an initial health advantage over their native counterparts, a phenomenon that researchers have coined the “healthy immigrant effect.” Dr. Krieger said, “To see this change in preterm birth rates is troubling because normally immigrant populations enjoy a health advantage over the native population.”

“One strength of the study is that we analyzed all birth certificates during the chosen time period to eliminate any selection bias,” she explained. “Additionally, the other factors that impact preterm birth rates such as body weight, education-level of the mother, smoking, etcetera, are unlikely to change over the small time period we measured which allows you to really see what impact the current political environment is having.”

Krieger’s study is not the first to find a connection between heightened racial profiling and adverse health. In 2017, researchers analyzed changes in birth outcomes in Postville, Iowa, after 2008, when the town experienced what was at the time the largest single-site federal immigration raid in U.S. history. Infants born to Latina mothers had a 24 percent greater risk of low birth weight after the raid as compared to the same period one year earlier. Similarly, a 2006 study from the University of Chicago found that, in the six months after the September 11 attacks, women of Arabic descent had a higher risk of poor birth outcomes than other groups. Specifically, women with Arabic names were 34 percent more likely to deliver children with low birth weight in the six months after 9/11 than in the six months before.

For immigrants living in New York City, the city maintains a list of ways to access health care; NYC Well is a free service that provides short-term counseling and assistance in accessing mental health resources in over 200 languages.

Ultimately, the hope is that studies like this will prompt physicians to think about how their immigrant patients may be affected by politics. Krieger said, “Although physicians cannot directly fix the problem, if they are thinking about it, they can connect patients with existing resources and bring more awareness to the issue.”