According to the report, released yesterday by Institute for Health Metrics and Evaluation, the number of women who die during -- or as a result of -- childbirth has risen nearly 3 percent since 2003.
In 1990, the maternal death rate per 100,000 U.S. women was 12.4. In 2003, it was 17.6. Last year, it rose to 18.5.
Other countries suffering a similar trend include Afghanistan, Belize and El Salvador, while most other developed countries feature much lower maternal mortality rates.
Trying to understand the reason for this alarming increase in the U.S. has proven difficult for health experts, but study author Nicholas Kassebaum -- a researcher at the University of Washington in Seattle -- suggests the rise could reflect "the performance of the health system as a whole," as well as "poorer access to essential health care."
"It certainly seems plausible that one of the underlying causes is that more mothers are ill when they start their pregnancies," Kassebaum told USA Today.
Notable deaths of 2014 [PHOTOS]