Irregular and long menstrual cycles have been associated with a higher risk of major chronic diseases including ovarian cancer, coronary heart disease, Type 2 diabetes and mental health problems, the study said.
Chan School of Public Health, Harvard Medical School, Michigan State University and Huazhong University of Science and Technology in Wuhan, China.
No cause for alarm
Experts said that women who experience irregular or long menstrual cycles shouldn't be alarmed by the findings of the study.
The study was observational and can only establish a correlation, not a causal link, between an irregular or long menstrual cycle and premature death.
"The important point illustrated by this study is that menstrual regularity and reproductive health provides a window into overall long term health," said Dr.