Recent Increases in the US Maternal Mortality Rate Disentangling Trends From Measurement Issues

OBJECTIVE: To develop methods for trend analysis of vital statistics maternal mortality data, taking into account changes in pregnancy question formats over time and between states, and to provide an overview of U.S. maternal mortality trends from 2000 to 2014. METHODS: This observational study analyzed vital statistics maternal mortality data from all U.S. states in relation to the format and year of adoption of the pregnancy question. Correction factors were developed to adjust data from before the standard pregnancy question was adopted to promote accurate trend analysis. Joinpoint regression was used to analyze trends for groups of states with similar pregnancy questions. RESULTS: The estimated maternal mortality rate (per 100,000 live births) for 48 states and Washington, DC (excluding California and Texas, analyzed separately) increased by 26.6%, from 18.8 in 2000 to 23.8 in 2014. California showed a declining trend, whereas Texas had a sudden increase in 2011-2012. Analysis of the measurement change suggests that U.S. rates in the early 2000s were higher than previously reported. CONCLUSION: Despite the United Nations Millennium Development Goal for a 75% reduction in maternal mortality by 2015, the estimated maternal mortality rate for 48 states and Washington, DC, increased from 2000 to 2014; the international trend was in the opposite direction. There is a need to redouble efforts to prevent maternal deaths and improve maternity care for the 4 million U.S. women giving birth each year.