Reduced odds of severe maternal morbidity associated with the US Affordable Care Act dependent coverage provision

Continuous perinatal health insurance coverage is a policy intervention that may help reduce severe maternal morbidity (SMM) and racial and ethnic disparities in SMM in the United States. The Affordable Care Act Dependent Coverage Provision (DCP) allowed young adults to remain on their parent's private health insurance plan until their 26^th birthday but its effectiveness in reducing SMM has not been evaluated.

To assess the association of the DCP with SMM during delivery hospitalization.

Difference-in-differences analysis of US delivery hospitalizations from January 2006 to September 2015, stratified according to maternal race and ethnicity. The outcome was SMM exclusive of blood transfusion only, as defined by the Centers for Disease Control and Prevention criteria. The exposure was maternal age categorized into 21 to 25 years (covered by the DCP) and 27 to 31 years (not covered the DCP). The intervention was the DCP categorized into pre- and post-DCP periods (January 2006-September 2010 and October 2010-September 2015, respectively).

Of the 4,007,937 delivery hospitalizations in the sample, 22,540 (56.2 per 10,000) recorded SMM. For birthing people aged 21 to 25 years (covered by the DCP), the mean SMM rate was 48.9 per 10,000 during the pre-DCP period and 58.2 per 10,000 during the post-DCP period (crude difference: 9.3 per 10,000). For birthing people aged 27 to 31 years (not covered the DCP), the mean SMM rate was 53.4 per 10,000 during the pre-DCP period and 63.6 per 10,000 during the post-DCP period (crude difference: 10.2 per 10,000). Implementation of DCP was associated with a 1.2% (95% CI: -3.6, 1.3) relative decrease in the mean SMM rate (adjusted odds ratio (aOR): 0.988; 95% CI: 0.964, 1.013). For non-Hispanic White people, the DCP was associated with a 10.7% (95% CI: 7.1, 14.2) relative decrease in the mean SMM rate (aOR: 0.893; 95% CI: 0.858, 0.929). The DCP was associated with an increase in the proportion of privately insured (aOR: 1.225; 95% CI: 1.220, 1.231), a decrease in the proportion of Medicaid beneficiaries (aOR: 0.853; 95% CI: 0.849, 0.856), and a decrease in the proportion of uninsured (aOR: 0.807; 95% CI: 0.798, 0.816).

Maternal health benefit of the DCP appears to be limited to non-Hispanic White birthing people.