The U.S. economic inequality gap has been widening for decades, and research shows that maternal disadvantage may have health consequences for newborns. A review of recent economic research, however, finds that the health of newborns has actually improved nationally in recent years, despite data that would suggest otherwise.
"That was really surprising to us," said Anna Aizer, associate professor of economics at Brown University. Aizer and Janet Currie of the National Bureau of Economic Research and Princeton University published the review in a special issue of Science dedicated to inequality research.
Aizer and Currie looked at economics research from the last four years to get a picture of how maternal disadvantage affects the health of newborns. The research highlights four conditions common to disadvantaged mothers that can affect newborn health: poor health behaviors during the prenatal period; greater exposure to harmful environmental factors, including the direct effect of toxic pollutants, violence, and stress, combined with a lower likelihood of taking action to avoid potential harms; poorer access to medical care; and worse underlying health, including poorer nutrition.
But when looking at research that assessed newborn health at birth, Aizer and Currie found that the rate of low birth weight of newborns, a strong indicator of poor health, has actually gone down among disadvantaged mothers over the last 20 years. That number has remained relatively constant among advantaged mothers within the same timeframe.
The authors suggest that an increase in public policies and programming in recent decades may be starting to break the cycle of poverty, with more women receiving the health care, nutrition, and education they need to improve their health prior to pregnancy and the health of their babies once they are born.
Attributing this improvement to policy "seems like the obvious answer," Aizer said. "We know a lot more about improving health at birth than we did 20 years ago and there are more policies now that are trying to do just that."
The authors highlight the food stamp program, the Supplemental Feeding Program for Women, Infants, and Children, and the more recent Nurse Family Partnership program as examples of programs that have demonstrated positive effects on prenatal health. They also note that the reduction in pollution nationally since the 1980s is a direct result of changes in policies that also greatly affected prenatal health.
Postnatal interventions, such as early education and income-transfer programs, have also been found to be effective at counteracting some of the negative effects of poor health at birth.
Despite the efficacy of both prenatal and postnatal programs, Aizer cautions against policymakers favoring one type of intervention over the other before more research can be completed.
"I think it would be a mistake in policy if the additional resources provided during the prenatal period are not followed up with additional resources postnatal," Aizer said.
The next step, said Aizer, may be to understand better which policies are most effective for which populations, so that valuable resources can be targeted without waste.
"From a policy perspective, you really do need to know where to put your money. It's more nuanced that just one program being more effective than another. It's a matter of getting a better handle on which of these policies is most effective and for which types of moms."