Despite rapid medical and technological advances aimed at increasing life expectancy, it seems women today are missing out on benefiting from such progress.

According to recent studies, the life span for women has decreased over the last two decades, with women today expected to have a much shorter life span than their mothers, The Atlantic reported.

In one study conducted by the University of Wisconsin and published in March, researchers found that female mortality rates rose in 43 percent of U.S. counties from the early '90s to 2006 and that women aged 75 and younger were dying at higher rates than their predecessors. At the same time, the life expectancy for men did not change.

A more recent report confirmed these findings, revealing that female life expectancy either stagnated or declined in 45 percent of U.S. counties between 1985 and 2010.

In both studies, scientists are baffled about what is causing the decline, although some attribute the higher mortality rates to obesity, smoking rates and higher education levels.

Co-author of the Washingston study, David Kindig, said he was so shocked by the findings that he did the numbers again only to find the same result. He lso said that health care, or lack thereof, may not be the whole story:

“'More and more people are beginning to realize that the non-health-care factors are at least as important… It could be cultural, political, or environmental, but the truth is we don't really know the answer,’ he told The Atlantic.

However, one factor affecting mortality remains clear and that is location. There is a clear link between where women live in the United States and their life expectancy. Women in the Southeast are most affected, particularly in Kentucky, West Virginia, Tennessee and Arkansas, while the Northeast is least impacted by the trend. Women in Florida lived an average age of 85.8 years, while in West Virginia the average age of death was only 74.

In addition, a Health Affairs study published in 2012 revealed that life expectancy amongst white, high school dropouts has declined significantly in the last 18 years – with this group expected to die five years earlier than the generation before.

Despite the dire news, life expectancy at birth in the United States remains unchanged and women continue to exceed men in their overall lifespan by approximately five years, according to a National Centre for Health Statistics study cited by HuffPost.