Two conditions common during women's childbearing years may increase their odds for serious illness and premature death, a large study shows.

Drawing on data from close to 111,000 women and three decades of monitoring, researchers linked endometriosis and uterine fibroids to a greater likelihood of dying early, especially from cancer.

"These findings highlight the importance for primary care providers to consider these gynecological disorders in their assessment of women's health," the team led by Yi-Xin Wang, of Shanghai Jiao Tong University in China, reported in the Nov. 20 issue of the BMJ.

Endometriosis is a common condition in which uterine-like tissue grows outside the uterus. Fibroids are noncancerous growths in or near the womb.

Both are linked to an increased risk for chronic diseases, including high blood pressure, heart disease and some cancers. The new research explored their effect on a woman's risk of dying before the age of 70.

Researchers drew on data from a massive study launched in 1989 when women were 25 to 42 years of age. Participants had no prior history of hysterectomy, heart disease or cancer.

Every two years, starting in 1993, they reported any confirmed diagnosis of endometriosis or uterine fibroids. 

Over 30 years of follow-up, 4,356 women died prematurely — 1,459 from cancer, 304 from heart diseases and 90 of respiratory diseases, the study found. 

Women who had endometriosis had a 31% higher risk of dying early, the study showed. Cancers of the reproductive organs were the most common cause of death.

Though researchers did not link fibroids to premature death from all causes, they found that fibroids did increase a woman's risk of dying from gynecological cancers.

In their analysis, researchers accounted for such factors as age, ethnicity, reproductive history, use of hormone therapy and birth control pills and other health-related issues. Women's weight, diet, exercise and tobacco use were also considered.

But they noted that participants were predominantly white healthcare workers so the findings may not apply to other groups. They added that other factors not measured may also play a role.

While the findings don't prove cause-and-effect, they do suggest that women with a history of endometriosis or fibroids might have a risk of early death even after their childbearing years, researchers said.

"These conditions were also associated with an increased risk of death due to gynecological cancers," they wrote in a journal news release. "Endometriosis was also associated with a greater risk of non-cancer mortality."