PROVIDENCE, R.I. [Brown University] — After several decades of improvement, inequality in infant health is once again on the rise in the United States, a pair of Brown University researchers has found.
Between 1989 and 2010, the health gap between infants born to the most socially advantaged mothers — those who are married, highly educated and white — and infants born to the least socially advantaged mothers — those who are unmarried, without a high school diploma and Black — steadily decreased. But according to a new study, that trend began to reverse in 2010, creating an ever-widening gulf that could last for generations.
“Lots of Americans view the U.S. as a land of equal opportunity where hard work pays off,” Emily Rauscher, an associate professor of sociology at Brown. “But equality of opportunity is fundamentally impossible to achieve as long as there is inequality in infant health. When babies are born in under-resourced communities, they are more likely to be born underweight or malnourished. They’re already at a disadvantage before they’ve even had an opportunity to do anything in the world.”
Rauscher conducted the study with David Enrique Rangel, an assistant professor of education — both are affiliated with Brown’s Population Studies and Training Center. The results were published in the journal Social Science & Medicine — Population Health.
The coauthors said they were motivated to investigate the trend in infant health inequality after the possibility of a shift came to their attention in conducting research on how maternal education affects infant health. As they combined data from Rauscher’s previous research on the effects of parent education levels on infant health with existing data on the effects of maternal race and ethnicity on infant health, they noticed that the data suggested a recent increase in inequality — a worrisome departure from the decades-long decline in inequality identified by Brown economist Anna Aizer in an influential 2014 paper.
The trend is a concern, Rauscher and Rangel explained, because multiple studies have shown that when infants are born underweight or more than three weeks before their due date, they may face health complications that could affect mental, physical and economic well-being for years to come. Those health complications are more likely to occur in infants born to mothers who face social and economic disadvantages, studies show, because they are more likely to experience high levels of stress, live in areas with limited access to affordable, nutritious food and come into contact with harmful chemicals in places where they live and work.
“The social conditions of living in an under-resourced community — more exposure to carcinogens, less access to healthy food, more stress — result in poorer infant health outcomes, like issues with cognitive development,” Rangel said. “That could result in a child struggling in school or an adult struggling to find a job. That could mean a child exhibiting externalizing behaviors — lashing out at peers.”
To confirm that their preliminary findings were correct, the authors analyzed three decades of data from the National Vitality Statistics System, a birth registry that records key infant health statistics and maternal race, marital status and education level. Like Aizer, they found that between 1989 and 2010, health disparities between infants born to mothers at opposite ends of the socioeconomic spectrum had gradually narrowed, leading to better health outcomes for infants born in more disadvantaged communities.
“One of the major reasons why inequality decreased in these decades was because there was an increase in knowledge about what led to good fetal health outcomes,” Rauscher said. “Doctors have learned that things like folic acid supplements and routine checkups can make a big difference in infant health. Nowadays, almost every OBGYN in every town has an MRI machine, which allows them to do the ultrasounds that help them catch slow growth early. They know that diabetes, pre-pregnancy hypertension and smoking during pregnancy are all major risk factors.”
However, the researchers found that that decades-long pattern of improvement seems to have reversed course in the last few years. Their data show that infant health inequality in the U.S. seems to have grown steadily over the last few years in concert with increasing income inequality, which has now reached a 50-year high. Over the last decade, the researchers observed that gaps in health between Black and white infants remained relatively stable. But health inequality increased between infants born to married and unmarried mothers and between mothers at opposite ends of the educational attainment spectrum.