CDC Vastly Overestimated U.S. Maternal Death Rates, Says New Study (original) (raw)

"U.S. maternal deaths keep rising," reported NPR last year. PBS similarly observed, "U.S. maternal deaths more than doubled over 20 years." CNN also reported, "US maternal death rate rose sharply in 2021, [Centers for Disease Control and Prevention (CDC)] data shows, and experts worry the problem is getting worse."

The increase in maternal deaths is a statistical illusion argues a new study just published in the American Journal of Obstetrics & Gynecology. "Our study, which identified maternal deaths using a definition-based methodology, shows stable rates of maternal mortality in the United States between the 1999–2002 and 2018–2021 periods," conclude the authors. That's wonderful news but what accounts for the headlines that cited a steep rise in maternal deaths?

The researchers note that maternal deaths began to rise in 2003 when a pregnancy check box was added to U.S. death certificates. Consequently, if a woman who was pregnant and died in a car crash, from heart disease, or cancer the box was marked and counted as a maternal death in the CDC's National Vital Statistics System. This statistical misclassification process is what has largely resulted in the reported steep rise in maternal deaths. As the press release accompanying the new study explains:

The CDC method showed maternal death rates of 9.65 per 100,000 live births in the 1999-2002 period and 23.6 in the 2018-2021 period, while the alternative method calculated death rates of 10.2 and 10.4 per 100,000 live births, respectively. These startling statistics discount the previously held belief that the United States maternal death rates have been increasing.

In even better news, the researchers found evidence that health care during pregnancy and after delivery, rather than worsening, has actually improved substantially in many areas. In addition, they found a slight narrowing of differences in maternal death rates by race.