BACKGROUND AND PURPOSE:

• Both preterm birth and low birth weight are associated with adverse infant outcomes such as
  • Increased risk of mortality
  • Chronic health conditions
• Black women are at higher risk while risks for Hispanic population are similar to non-Hispanic white population
• Medicaid expansion under the Affordable Care Act allows states to extend coverage to low-income women regardless of pregnancy status, which may lead to reduced infant mortality
• Brown et al. (JAMA, 2019) studied whether Medicaid expansion has impacted rates for low birth weight or preterm outcomes

METHODS:

• Observational study (data from 2011-2016)
• Participants
  • Singleton live births to women
  • ages ≥19
• Data
  • Population-based data from the National Center for Health Statistics Birth Data Files
• Group designation by
  • State Medicaid expansion status
  • Racial/ethnic category
• Analysis
  • Compare birth outcomes among infants in Medicaid expansion states and non-Medicaid expansion states
  • Compare changes in relative disparities among racial/ethnic minorities
• Primary outcomes (dependent variables)
  • Preterm birth (<37 weeks) and very preterm birth (<32 weeks)
  • Low birth weight (<2500 g) and very low birth weight (<1500 g)

RESULTS:

• 15,631,174 births
• Racial/ethnic category
  • White infants: 8,244,924
  • Black infants: 2,201,658
  • Hispanic infants: 3,944,665
• Features of states with Medicaid expansion
  • Higher median incomes | Lower percentage of uninsured females | Higher percentage of minority females | Higher number of primary care physicians | Higher percentage of adults who had their cholesterol checked in the last 5 years | Higher percentage of first trimester prenatal intake
• Medicaid-expansion status
  • 18 states with expansion: 8,530,751
  • 17 states without expansion: 7,100,423
• There was no significant change in any of the primary outcomes overall between expansion and non-expansion states

• Preterm birth (prexpansion to postexpansion); P = .98
  • Expansion state: From 6.80% to 6.67%
  • Non-expansion state: From 7.86% to 7.78%
• Very preterm birth; P = .37
  • Expansion state: From 0.87% to 0.83%
  • Non-expansion state: From 1.02% to 1.03%
• Low birth weight; P = .20
  • Expansion state: From 5.41% to 5.36%
  • Non-expansion state: From 6.06% to 6.18%
• Very low birth weight; P = .14
  • Expansion state: From 0.76% to 0.72%
  • Non-expansion state: From 0.88% to 0.90%
• However, when data was broken out by race, differences between black infants compared to white infants was reduced in expansion states for all primary outcomes, indicated by a negative difference-in-difference-in-difference coefficient
  • Preterm birth (10.21% to 9.61%): −0.43 percentage points [95% CI, −0.84 to −0.02], P = .05
  • Very preterm birth (1.97% to 1.81%): −0.14 percentage points [95% CI, −0.26 to −0.02], P = .03
  • Low birth weight (9.96% to 9.50%): −0.53 percentage points [95% CI, −0.96 to −0.10], P = .02
  • Very low birth weight (1,82% to 1.69%): −0.13 percentage points [95% CI, −0.25 to −0.01], P = .04
• This benefit in Medicaid expansion was not seen for Hispanic infants

CONCLUSION:

• There was no statistical difference overall between states that did and did not expand Medicaid
• However, when refining the analysis based on race, there was a significant decrease in disparities in preterm birth or low birth weight for black infants
• The authors state

The findings here suggest that earlier and continual access to insurance coverage may provide an important opportunity for improving infant outcomes.

Learn More – Primary Sources:

Association of State Medicaid Expansion Status With Low Birth Weight and Preterm Birth

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