For years some women have monitored their biological clock, to help them with family planning and other important life decisions. Now, researchers may have found a way to pinpoint when the menopause alarm will sound.

A study by researchers at the University of Michigan and published in the Journal of Clinical Endocrinology & Metabolism found that a decrease in three different biomarkers may help them predict the beginning of menopause before it sets in.

The researchers found that the biomarker anti-Mullerian hormone significantly decreased about five years prior to the onset of menopause.

“This information provides a roadmap as to how fast women are progressing through the different elements of their reproductive life. People really want information about ‘how long do I have and when will I have my final menstrual period,’” said MaryFran R. Sowers, PhD from the University of Michigan School of Public Health

According to the Centers for Disease Control and Prevention, menopause generally occurs in women between the age of 45 and 55 years old.

As of the 2000 census there are some 37.5 million women in the U.S. at or reaching menopause age.