Every woman who isn’t yet in menopause wonders when the change will happen. Now there’s a new clue—if you had your first period younger than most girls do, you are more likely to go into menopause younger than most women do. Unfortunately, that’s linked to increased health risks. Indeed, it’s a wake-up call to take steps now to protect your health.

Background: Most women enter menopause, defined as 12 months after the final period, when they are between 45 and 55. But some women enter menopause when they’re younger. Early menopause happens when you are 40 to 44—and it is linked to increased cardiovascular risk. Premature menopause happens before age 40 and is even more strongly linked to increased risk for chronic diseases including cardiovascular disease, type 2 diabetes and osteoporosis. (Early and especially premature menopause also call for different treatment plans, including hormone therapy.) While medical issues, especially surgical removal of both ovaries, can bring on premature or early menopause, for many women there is no apparent cause.

Study: Australian researchers pooled data from nine observational studies in the UK, Scandinavia, Australia and Japan that followed more than 50,000 women who went into “natural” menopause—that is, it wasn’t caused by a medical issue. Each woman’s age at her first period and age at menopause was tracked.

Results: Women who had their first periods when they were age 11 or younger—about 14% of the women—were 30% more likely to go into early menopause and 80% more likely to go into premature menopause than women whose first periods occurred at age 12 or older.

Surprising finding: Not having children increased the odds of early and premature menopause for women with early first periods. For example, compared with women who had a first period at age 12 or older who had two children, women with a first period at age 11 or younger who had no children were twice as likely to go into early menopauseand five times as likely to go into premature menopause. The probable reason—when you’re pregnant, you’ll go nearly a year without a menstrual cycle. Since women are born with a finite number of eggs, fewer menstrual cycles means fewer eggs are released, which extends the number of years that you’ll continue to menstruate—delaying menopause.

Bottom line: If you had your first period at age 11 or earlier, and especially if you also haven’t borne a child, pay attention to early signs of the menopause transition. If it looks like you’re going to enter menopause before age 45 (or you have already done so), talk to your doctor about ways to manage menopause and reduce your risk of cardiovascular disease, type 2 diabetes and osteoporosis.