“Maternal deaths in the United States continue to rise,” NPR reported last year. PBS similarly noted, “maternal deaths in the United States have more than doubled in 20 years.” CNN also reported, “The US maternal mortality rate increased sharply in 2021, [Centers for Disease Control and Prevention (CDC)] data shows, and experts fear the problem is getting worse.”
The increase in maternal deaths is a statistical illusion, claims a new study just published in American Journal of Obstetrics and Gynecology. “Our study, which identified maternal deaths using a definition-based methodology, shows stable rates of maternal mortality in the United States between the periods 1999-2002 and 2018-2021,” the authors conclude. This is wonderful news, but what explains the headlines citing a sharp increase in maternal deaths?
Researchers note that maternal deaths began to increase in 2003, when a pregnancy checkbox was added to U.S. death certificates. As a result, if a pregnant woman died in a car accident, from heart disease, or from cancer, the box was flagged and counted as a maternal death in the CDC’s National Vital Statistics System. This process of statistical misclassification is what has largely driven the reported sharp increase in maternal deaths. As the press release accompanying the new study explains:
The CDC method showed maternal mortality rates of 9.65 per 100,000 live births from 1999-2002 and 23.6 from 2018-2021, while the alternative method calculated mortality rates of 10.2 and 10.4, respectively per 100,000 live births. These startling statistics disprove previously held beliefs that maternal mortality rates in the United States are increasing.
Even better news is that researchers have found evidence that health care during pregnancy and after childbirth, rather than getting worse, has actually improved substantially in many areas. Additionally, they found a slight reduction in differences in maternal mortality rates by race.