According to the Centers for Disease Control and Prevention (CDC), the maternal mortality rate in the United States is very high compared to other wealthy countries: About 22.3 maternal deaths per 100,000 live births. This is on par with China and Iran, based on UNICEF data.So why is the US maternal mortality rate so high? It may have to do with how we fill out death certificates.A study from earlier this year found that misfiling of information in death certificates may be inflating the numbers. The study authors concluded that the US maternal mortality rate was actually half of the CDC-reported rate—about 10.4 per 100,000 live births—which is in line with countries like Canada and the United Kingdom.But if death certificates can skew maternal mortality statistics by such a huge margin, what else could they be influencing? And how does our system for filling out death certificates work?To answer these questions, guest host Maggie Koerth is joined by Dr. Robert Anderson, chief of the statistical analysis and surveillance branch at National Center for Health Statistics.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.