Study: Medicaid’s benefits start in the womb

The best evidence we have suggests that having health insurance improves access to care, resulting in improved health. But can those effects actually start before birth? According to a new study supported by the Robert Wood Johnson Foundation, that appears to be the case.

The idea isn’t as strange as it might sound: there’s a strong consensus that the in-utero fetal environment has strong and persistent effects on adult health down the road. But most research on this has focused on things that negatively impact fetal development and future health, like poor nutrition and maternal infection. Fewer studies have tried to tease out potentially positive effects from policy changes affecting pregnant women and young children.

A few decades ago, the nation extended the reach of Medicaid, a public health insurance program for the poor. The program expanded rapidly during the 1980s to cover more pregnant women and children; this made prenatal care much more accessible to low-income women, many of whom would have been uninsured during pregnancy otherwise.

That expansion unfolded at different times in different states, and this variation allows researchers to track how Medicaid impacted health outcomes over the lifetime of children whose first “exposure” to Medicaid was before they were born.

And it turns out that exposure is a boon for health.

When Medicaid eligibility rose 10 percentage points for pregnant women, probability of being obese declined by about 7 percent for adults who had been in-utero during expansion. For the same increase in maternal eligibility, preventable hospitalizations also fell by 7 percent for adults, the study found. Chronic disease-related preventable hospitalizations fell by 9 percent and hospitalizations related to endocrine, nutritional, metabolic and immunity disorders dropped 8 percent.

The authors also find health improvements when gaining access to Medicaid occurred during infancy or other periods of early childhood, but those effects are smaller than the ones associated with in-utero coverage.

This is consistent with similar research that has been conducted on food assistance. Children who gained access to the food stamps program before being born (that is, their mothers gained access during pregnancy) and during very early childhood had lower rates of obesity, diabetes, and high blood pressure in adulthood.

Most research on changes in health policy, like expanding health insurance coverage, focus on short-term impacts. This study suggests that such a lens is too narrow — some benefits won’t become apparent until ten, twenty, even thirty years down the line.

“Although most research has found that expanding health insurance coverage increases the immediate use of care among beneficiaries, our results highlight that providing health insurance coverage to low-income families during critical periods of development may reduce the need for costly care in the future,” the authors write. “Our results suggest that public health insurance expansions have benefits that materialize years after their implementation.”