Women's Health Community

Dear courtenydsmith: The most common reason for a menstrual pattern like you have described (once pregnancy is ruled out) is not having an ovulation every month. In a normal cycle, estrogen is produced all month. Estrogen is responsible for building up the lining of your uterus so you have something to shed each month. The good news is that you have had enough estrogen to make a lining that does shed sometimes.

In a normal cycle, progesterone production increases following ovulation and release of an egg.. Progesterone "stabilizes" the uterine lining in preparation for a possible implantation of a new pregnancy. If you are not pregnant that month the levels of estrogen and progesterone fall, triggering the release of the uterine lining—your period. So, if you do not ovulate, the estrogen build up of the lining continues, but without the usual ovulation associated progesterone. Thus, the hormone levels don't decline, and the lining stays up inside the uterus—your missed period.

Causes for not ovulating are multifold: thyroid problems, pituitary problems, ovarian cysts, physical stressors (eg sudden increases in exercise, crash dieting), emotional stressors (problems with family or boyfriends/girlfriends, finances), increased body weight, anorexia, rotating shifts at work, etc.

If you have been several months without a period, a gynecologist may give you some progesterone in a pill form (eg Provera 10 mg for 5 days). Within 48-72 hours after stopping the progesterone your "progesterone blood level" will fall, triggering the release of the lining that has been building up. Many women report that these periods are very heavy-- as though several months of lining are shed.

There is a second, less common cause for not having a period. In some women the estrogen levels become very low. The levels are so low that no uterine lining is available to be shed. When these women are given the progesterone pills to take, no flow occurs after the medication is finished. This tells the GYN that the woman is not making enough estrogen to produce a thickened uterine lining. While this is a rare condition in a young woman, premature menopause can occur.

Lastly, everything I have just shared with you pertains to women who are NOT using a form of hormonal birth control. If you are using an oral contraceptive, or DepoProvera, or other hormonal contraceptive you may miss a period (s) for an entirely different reason. Once pregnancy has been "ruled out" (because even reliable methods fail) one can usually assume that the missed period is "normal" or "OK". Unlike the scenarios discussed above, women on hormonal contraception have both estrogen and progesterone available. If the synthetic progesterone is dominant, it can artificially make the uterine lining very thin. So the woman misses her "Pill period" or it is very much lighter than normal. Of note, if you are on a form of hormonal contraception, and you miss a period (s), you will not have a uterine lining build up.

I would strongly suggest that any woman who suddenly begins to misses periods consult with her GYN. They will help you sort out which of the reasons mentioned above is the cause for your lack of a period.

Yours,
Jane