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Why Aren't My Periods Regular?

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Why Aren't My Periods Regular?

Apr 17, 2014

What if your periods aren’t regular? Is that normal? Dr. Kirtly Jones tells you what is considered a ‘regular' menstrual period cycle, and what to do if your periods aren’t regular. She also talks about why some periods might come early, some later, and some not at all.

Episode Transcript

Dr. Kirtly Parker Jones: Period. The punctuation at the end of a sentence that the Australians call the full stop. An amount of time in a high school day. Third period. Lots of other meanings. But to women, it means their menstrual period, and it assumes some periodicity, regularity. But what if it isn't regular? Is that normal? Or is there a problem? This is Dr. Kirtly Jones from the Department of Obstetrics and Gynecology at University of Utah Health Care, and this is The Scope.

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Dr. Kirtly Parker Jones: My mother's generation called it my friend or falling off the roof. I remember the first time that I was in clinic in Boston and a patient's chief complaint was that her friend didn't come. My question to her was "Was there a problem with her travel plans? Was the train cancelled?" The young woman looked at me as if I were really clueless, and I was. What she meant was that her period was late. So is this a problem? What should you do about it?

Menstrual periods are called regular when the time between them is between 24 to 35 days. Women who have a 26-day cycle one month and a 31-day cycle the next are still called regular. Early in our evolution as humans, women were either pregnant, breastfeeding, or starving, all of which made periods absent or irregular. Today's idea that periods should be regular has only been part of our biology since we were well fed and life wasn't so calorically risky. Before several hundred years ago, most women on the planet were often at the lower limits of caloric intake, and periods were usually irregular.

All women are irregular at the beginning and the end of reproductive life. At the beginning, about 11 to 13, it takes about six months to get the system going, and irregular is the norm. If a woman hasn't achieved some kind of regularity in three years, there may be a problem. At the end of reproductive life, the perimenopause, 92% of women are irregular as the system grinds to a halt-menopause. But in between, women who were regular and then become irregular might want to see their clinician after the pregnancy test is negative. If it's positive, they should certainly see their clinician.

Common life changes can change a menstrual cycle. Weight gain or loss of as little as 15 pounds can disrupt the system. If the weight gain or loss isn't extreme or end up with women at the extremes of thinness or fatness, periods often settle themselves out again if a woman was regular before. Emotional or physical stress can disrupt a menstrual cycle for a month or two. Of course, if the illness is severe and ongoing, the disruption may continue.

Some women choose to limit the number of periods they have by their contraceptive method they use. Some contraceptive methods are associated with no periods or very light periods, and this is fine as long as this is a contraceptive effect. Some women manipulate the use of their contraceptive pill or patch or ring so they can take them continuously without a period break of one week each month, and these women choose to have their period every three months or six months or not at all.

So if you were regular and now you're not and none of the previous things apply, what could be going on? All of your brain hormones, thyroid hormones, and ovarian hormones have to be in sync to have a regular period. So women who become irregular should have a medical history and physical exam and have a couple hormones checked, their thyroid hormone and another hormone from the pituitary called prolactin. If these hormones are abnormal, things are pretty easily fixed. Of course, there are less common hormone problems, but your clinician can evaluate you for these if there are some clues from the medical history or the physical.

Some women run out of eggs early-premature menopause-either because they have an underlying condition that we understand to cause this or for no good reason. If periods become very irregular in a woman's thirties for no good reason, stress, weight gain or loss, pregnancy, etcetera, all that stuff we've talked about before, then the doctor might check a hormone called FSH, follicle-stimulating hormone, and see if it's high, suggesting there might not be so many eggs to grow and create the menstrual cycle.

So your friend didn't come and your pregnancy test is negative. Give it a month or so. But if she still didn't come, give your doctor's office a call, and we'll check it out. This is Dr. Kirtly Jones, and thanks for joining us on The Scope.

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