When the arrival of your period becomes more erratic than airplanes during the holiday travel season, you know something is up, especially if before they were like clockwork. Why this is happening and what this all means can be confusing. It can also make deciding if you should wear white jeans very difficult! Most fingers point towards the ovaries and their dwindling supply of eggs and specific hormones: think inhibin, estrogen, and AMH.
As the ovaries start to run on empty, they shoot mixed messages to the brain. The brain, which is used to orderly and steady hormone levels from the ovaries, is thrown into a tailspin. Without adequate ovarian hormone production, the brain overproduces certain hormones. Think FSH and LH. There goes the regularity of your menses. In medicine, we refer to this period of confusion and “crazy” period timing as perimenopause. And to put it bluntly, this period (no pun intended) can be a big pain.
In terms of the brain-ovary relationship, think of a seesaw. As the ovaries (egg production and select hormones) go down, the brain’s hormone production goes up—and in some cases, way up. FSH levels can reach the high double digits. Ovarian hormones and hormones in the brain, specifically the pituitary gland, work in a negative feedback loop—high ovarian hormones keep the brain’s reproductive hormones low. So when you are nearing menopause and the ovarian production lays low, lower, and then lowest, the seesaw will remain lopsided. And while on this seesaw, the person left high won’t get hurt, it will have a major impact on how frequently you see your periods—as well as other things like your internal temperature gauge.
For most of our reproductive lives, the ovaries and the brain work as a team to prepare an egg, ovulate an egg, and maintain the corpus luteum (a.k.a. the structure that makes progesterone and helps maintain a pregnancy). There are some conditions where this system doesn’t run so smoothly—cue PCOS, thyroid disease, or hypothalamic amenorrhea. But for most of us, it is pretty well-oiled machine, that is, until we hit our mid-40s or so. Then the pendulum starts to swing erratically. Periods come closer together (about 20 days) and then farther apart and then close together AND farther apart. Not a pleasant combo.
Consistency becomes a thing of the past. While your mind may view pregnancy as a thing of the past, your ovaries haven’t quite given up. They are still working to prepare and ovulate an egg each month. Because of the diminished supply, they start to prepare the egg in the second half of the menstrual cycle the month BEFORE that egg will be ovulated. Simply stated, they are letting the horse out of the gate (a.k.a. the egg) long before the race goes off (a.k.a. the next menstrual cycle starts). As a result, the menstrual cycles will get shorter and shorter.
Although irregular menstrual cycles are quite common when we hit our 40s and beyond, when bleeding becomes excessive or all of the time, you need to speak to your OB/GYN. While it likely means nothing more than the ovarian reserve fuel tank is running on empty, you want to make sure there is nothing structural (a polyp, a fibroid, or even a cancer) that needs to come out. Don’t brush it off as another joy of aging!
Just like any relationship, when one member of the team goes haywire, things can fall apart pretty quickly. If you are not in sync with your partner, the partnership falls apart. The brain and ovary alliance is no different. When one stops working, the other one tries to overwork or make up for the deficiencies, which leads to irregular and often frequent periods. Although there may be nothing you can do to mend or tame this wild relationship (once ovarian production goes down, it generally will remain down), just acknowledging it can bring you some peace.
And with that, you can go out and face the wild, wild west!