This data was collected from the CDC's Pregnancy Mortality Surveillance System. Since the system has been put in place reported pregnancy related deaths have increased from 7.2 deaths per 100,000 live births in 1987 to 23.8 deaths per 100,000s live births in 2020. According to the CDC, "the reasons for the overall increase in pregnancy-related mortality are unclear." However, to improve the underreporting of maternal mortality it was recommended to add a "pregnancy related death box" to death certificates.
*Note: Mortality rates are per 100,000 live births
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Source: Center for Disease Control (CDC)