Increased Medicaid Coverage Is Not Improving Low Birth Weight

Marc Joffe

With so many people obtaining Medicaid coverage in the wake of the Affordable Care Act and during the pandemic, it is worth investigating whether this expanded eligibility is improving health outcomes. Overall, decreases in the proportion of uninsured individuals over the last decade are not being matched by improved life expectancy. Indeed, life expectancy at birth in 2021 was lower than it was when the Affordable Care Act passed. But this fact tells us little about the benefits of Medicaid coverage since the decline has been driven in large part by COVID-19 deaths among elderly patients (often not on Medicaid) as well as increased mortality from accidents and drug overdoses.

To better gauge the benefits of Medicaid, it is necessary to look at more specific health indicators. The federal Center for Medicaid and CHIP Services (CMCS) compiles a large variety of healthcare quality measures that could help us analyze outcomes. Unfortunately, most of these measures are not available for all states and all years, making it difficult to assess performance in a systematic way.

One indicator that is generally available is the rate of low birth weight, which is the percentage of newborns weighing less than 2500 grams, or about five pounds eight ounces. Low birth weight (LBW) babies have “a higher risk of morbidity, stunting in childhood, and long‐​term developmental and physical ill health including adult‐​onset chronic conditions such as cardiovascular disease.” Consequently, reducing the incidence of LBW should improve public health, but Medicaid services are not achieving this outcome.

A 2019 study in JAMA found no correlation between Affordable Care Act Medicaid expansion and LBW. The authors used administrative records to obtain rates of LBW (and some other adverse birth outcomes) before and after Medicaid expansion in states that accepted the expansion and those that did not. The change in LBW rates in expansion states was not significantly different than that in non‐​expansion states. The authors did find some improvement for Black infants in expansion states, but not for white or Hispanic infants.

Overall, the US is not among the countries that have had the best success in minimizing low birth weight. A 2015 World Health Organization analysis ranked the US 64th among 146countries, with such less affluent nations as Albania. China, and Cuba performing better. Poor US outcomes have been attributed to the use of fertility drugs (which increases the likelihood that a mother will give birth to twins or triplets) and the high rate of Caesarian sections.

According to data from the CDC WONDER Database, 8.3% of US babies born in 2019 were low birth weight. The LBW rate among Medicaid patients was substantially higher, coming in at 9.8% (WONDER also has 2020 and 2021 data, but I chose 2019 data to avoid any pandemic‐​related affects).

In the District of Columbia, the LBW disparity between Medicaid‐​financed births and those with other types of coverage is especially stark. In 2019. DC’s overall LBW rate was 9.9%. For Medicaid births, it was 12.7% and for non‐​Medicaid births it was only 7.4%. And, it does not appear that this disparity is caused by a lack of access to government‐​paid medical services: the Medicaid and CHIP Payment and Access Commission (MACPAC) reports that (in 2018) 99.3% of DC Medicaid births took place in a hospital and that 91.7% were attended by a physician, with almost all of the remainder attended by a Certified Nurse Midwife.

The risk of low birth weight can be minimized through proper nutrition, not smoking, and avoiding narcotics. These risks can be controlled with non‐​medical interventions. For example, at‐​risk mothers can be accommodated at maternity homes, where their diet and substance use can be carefully supervised. The widespread use of maternity homes in Cuba may explain the low rate of LBW in that country (although Cuba’s health statistics have been subject to criticism).

WONDER provides statistics on tobacco use in pregnant women. In DC, the LBW rate among Medicaid tobacco users was 23.7%. Unfortunately, data are not available for other types of substance abuse or malnutrition, however Wallethub recently ranked DC’s drug use fifth among all states (plus DC).

Some states are devoting Medicaid resources to the “social determinants of health”, funding non‐​medical services such as housing and nutrition that are intended to address health inequities. DC has an Office of Health Equity that supports “projects, policies and research that will enable every resident to achieve their optimal level of health — regardless of where they live, learn, work, play or age.” But these added efforts are not making a dent in LBW.

Despite spending over $3 billion on Medicaid annually, DC (like other parts of the US), has pregnancy outcomes that are on a par with or even below those of developing countries. It appears that providing costly pregnancy services cannot substitute for the basic health precautions we hope all expectant mothers will take.