Maternal Deaths in US Saw Substantial Increase at Onset of COVID-19 Pandemic

Marie E. Thoma, PhD

New findings suggest maternal deaths in the United States increased substantially at the onset of the COVID-19 pandemic.

This figure (33.3%) was higher than a 22% overall excess death estimate associated with the pandemic itself and the increases were highest for Hispanic and non-Hispanic Black women.

“Change in maternal deaths during the pandemic may involve conditions directly related to COVID-19 (respiratory of viral infection) or conditions exacerbated by COVID-19 or other health care disruptions (diabetes or cardiovascular disease), but could not be discerned from the data,” wrote study author Marie E. Thoma, PhD, Department of Family Science, School of Public Health, University of Maryland.

Between 2019 and 2020, data from the National Center for Health Statistics (NCHS) reported an 18.4% increase in US maternal mortality. As such, the relative increase was 44.4% among Hispanic, 25.7% among non-Hispanic Black, and 6.1% among non-Hispanic White women.

To examine the role of the pandemic in maternal death rates, investigators used deidentified NCHS mortality and natality files from 2018 to 2020. Analyses were limited to maternal deaths based on underlying causes of death. They did not exclusively identify COVID-19 as the cause, even when it was a factor in maternal death.

Therefore, investigators noted COVID-19 was ascertained as a secondary cause from the multiple causes of death area, remaining consistent with other reports on excess mortality from COVID-19. The deaths were stratified by month and year of death into before (2018, 2019, and January - March 2020) or during (April - December 2020) the pandemic

Data show a total of 1588 maternal deaths (18.8 per 100,000 live births) occurred before the pandemic vs 684 deaths (25.1 per 100,000 live births) during the pandemic, at a relative increase of 33.3%. The findings additionally show late maternal mortality increased by 41%.

Moreover, the absolute and relative changes were highest for Hispanic (8.9 per 100,000 live births; 40.2%) and non-Hispanic Black (16.8 per 100,000 live births; 40.2%) women, compared to non-Hisapnic White (2.9 per 100,000 live births; 17.2%) women.

Investigators found the secondary code for COVID-19 was listed in 14.9% (102 of 684) of maternal deaths in quarters 2 to 4, with 0% reported in quarter 1 of 2020. The percentage was highest among Hispanic women (32.1%), followed by non-Hispanic Black (12.9%) and non-Hispanic White (7.3%) women.

Regarding underlying cause-of-death codes, data show the largest relative increase was among indirect causes (56.9%). The relative increases in direct causes (27.7%) were mostly associated with diabetes in pregnancy (95.9%), hypertensive disorders (39.0%), and other specified pregnancy-related conditions (48.0%).

Meanwhile, COVID-19 was often listed as a secondary condition with other viral diseases (16 of 16 deaths [100%]) and diseases of the respiratory system (11 of 19 deaths [57.9%]).

“Future studies of maternal death should examine the contribution of the pandemic to racial and ethnic disparities and should identify specific causes of maternal deaths overall and associated with COVID-19,” Thoma concluded.

The research letter, “All-Cause Maternal Mortality in the US Before vs During the COVID-19 Pandemic,” was published in JAMA Network Open.