Volume 2, Number 2: Summer Solstice, 2000

Ovulatory Menstrual Cycles are Not a Problem - BC Endocrine Research Foundation

Jerilynn C. Prior MD, FRCPC

Professor of Endocrinology, University of British Columbia, Vancouver, B.C.

Go With the Flow!

As a reproductive endocrinologist and feminist scientist studying women’s health, I am not surprised at the current hype that women needn’t suffer periods. Instead, take a birth control pill every day. Women of my, and subsequent, generations have been in love with the potential to control fertility. As Alice Rossi wrote, “Frankly, I regard the pill as more important in the development of the modern women’s movement than any amount of political literature” [1 p. 216 ]. Bernard Asbell, prize winning author of The Pill: a biography of the drug that changed the world, agrees [2].

That being said, however, the little book by Drs. Coutinho and Segal, Is Menstruation Obsolete?[3], is a biased, deceptive and inaccurate work. In fact, if the lay and medical literature [4,5 ] had not begun to write articles praising lack of menstrual flow, I suspect that few copies of this book would have been sold.

The story behind Is Menstruation Obsolete, however, is interesting. Dr. Elsimar Coutinho, a Brazilian physician, went as a trainee to New York in 1959 to work with renowned hormone chemist Dr. George Corner. There he met Dr. Sheldon J. Segal, a PhD scientist studying hormone actions. Over the years these two kept in touch so that Dr. Segal knew of Dr. Coutinho’s book published in 1996 titled (in translation ) Menstruation, a Useless Bleeding. Dr. Segal translated and revised it in English, because, he says, “We envisage a campaign. . .to educate the public about the uselessness of menstruation for women not actively seeking pregnancy” [3].

This book is a new, revised expression of cultural and medical prejudice. It is based on a medical world view that ignores women’s unequal status in society and double work load or says they are irrelevant to women’s health. It is a resurgence of the same deficiency theme – periods are now a “pill-deficiency disease!”

To start with, let’s talk about the misconception that “natural” primitive women didn’t have periods. In the early 1980s I began to study women’s menstrual cycles by examining changes that occur with exercise training [6,7]. Marathon training suddenly was deemed to cause amenorrhea (loss of menstrual cycles for six or more months) when women were first able to run longer distances. Immediately, amenorrhea became a serious disease for which (reckless, sweaty) women were to blame.

Since then I and others have shown that heavy marathon-like training does not cause amenorrhea 8-10. But medicine had found a powerful way of saying that intense exercise was not a feminine pursuit.

In my search to understand exercise and menstruation I found anthropological works about the modern hunter-gatherer! Kung peoples of the Kalahari Desert [11]. Rather than losing their menstrual flow, I suspected that the hard working! Kung women simply had protective suppression of ovulation (the release of an egg). The commonest changes I was observing with exercise-training were not in periods but in ovulation. Ovulation disturbances include not releasing an egg (anovulation typically with very low progesterone) or releasing an egg less than 10 days before the next period (short luteal phase usually with moderately low progesterone)[8]. We showed that the old fashioned “basal body temperature” method of fertility control could scientifically document the amount and duration of progesterone in cycles by a new statistical analysis of the temperatures data [12].

I learned, by studying runners, what is true for all women – ovulation and menstruation are not the same. Regular periods can and do occur with no ovulation or with disturbed ovulation[8,13,14]. However, like most doctors (and consequently, ordinary women), Is Menstruation Obsolete? implies that periods mean ovulation. It also infers that amenorrhea is (just) anovulation. In fact, amenorrhea means both estrogen and progesterone levels are low-a situation that always causes fast bone loss and the risk for osteoporosis.

The women I was studying, like the !Kung women, were lean but not undernourished and were not using hormonal contraception. !Kung women, I believed, had babies spaced an average of four years apart because of suppression of ovulation but not periods related to breast feeding on demand as well as their heavy physical activity. That idea was confirmed by the careful ethnography of Dr. Marjorie Shostak in Nisa -The Life and Words of a !Kung Woman [15] who recorded the words of Nisa who at eight observed her mother had blood on her leg and was told she was menstruating. “We continued to live and she menstruated again. It came to her when the moon was high in the sky at sunset. Then one moon passed by and other. . . She was pregnant again&” [15 p. 73]. In other words, when women had regular periods they knew they were not pregnant. This doesn’t sound to me like a people with rare menstrual flow!

Nisa also knew that, although she and other !Kung women married before menarche and menstruated from about 16 years of age, for the first one to three years they were generally infertile 15. As is common in modern adolescence, ovulation is not well established for several years [13,14,16].

Not only did Nisa, the modern day hunter-gatherer woman understand regular cycles without pregnancy in adolescence, she graphically describes perimenopause: “After that, there was nothing more; I didn’t get pregnant again. I just kept menstruating, for months, for years” [15 p. 326]. Typically, perimenopausal women will have several years of regular menstrual cycles with higher than normal estrogen levels but inadequate ovulation [17,18].

By contrast with Nisa who made accurate observations and deductions, Dr. Coutinho and Segal generalize wrongly: “From the time of menarche, perhaps even before their first menstruation, young women were either pregnant or lactating almost continuously.” [P. 2]. The implication is that lactation means no periods, but as any “la leche league” mom knows, menstruation may return long before weaning. These scientists betray their bias,”Simply put, a human menstrual period is the result of failure. . . ” [p.4].

Not only are Drs. Coutinho and Segal wrong about early women and their ovarian cycles, they seriously misrepresent both the prevalence and the menstruation-related difficulties of modern women. As an example, they state “premenstrual syndrome” or “PMS” causes”significant discomfort” for “30 to 40 percent of the female population” (p. 67). By contrast, careful epidemiological data show that PMS occurs in only one percent of the population of reproductive aged, menstruating women not taking oral contraceptives [19].

The point is – normally ovulatory cycles are not distressing. The problem is not with menstruation, it is with ovulation disturbances coupled with the typically high estrogen levels of modern, inactive and stressed women.

I believe this “campaign” to obliterate periods is a disguised form of direct-to-consumer drug advertising (which Canada bans). If it were not for the purpose of selling the new three-month birth control pills (that are apparently already available in countries other than Canada), these authors would emphasize the available methods to suppress flow. For the same reason it omits to mention effective prevention or treatment strategies for the supposedly horrid consequences of menstruation. For example, over-the-counter ibuprofen prevents or treats dysmenorrhea. An effective decrease in premenstrual symptoms without suppressing ovulation results from gradually increasing exercise 20 as well as from calcium supplementation [21]. And cyclic progesterone or medroxyprogesterone therapy will control heavy flow, help cramps [22] and decrease bone loss [23].

The media coverage expected and received for this book, provide a clever strategy to soften the market for new continuous oral contraceptives. Perhaps this story is fascinating to editors because cultural etiquette prohibits speaking/writing of periods. Malcolm Gladwell in his large piece in The New Yorker states that Dr. John Rock, the gynecologist prominent in the early testing and production of the pill, was manipulating both women and the Catholic Church in making pill-withdrawal bleeding mimic menstruation 4. A nude, young woman covered only with pill packets is draped by the headline: “bare facts about the Pill” (Globe and Mail April 8, 2000). Most recently, CNN (on May 9, 2000) lauded the 40 year success of oral contraceptives. The reporter could find no “expert” who would question the daily pill use (other than me). Over and over, medical experts in the English speaking world have been trotted out to say that there is no health reason for menstrual flow. They support the notion that cycles are a “disease or condition” that should be obliterated 5.

The English edition of Is Menstruation Obsolete? skillfully co-opts the women-centred literature on menstruation. For example, it mentions Emily Martin’s anthropological work about the language used to describe women’s bodies 24, and Sophie Law’s Issues of Blood 25. The forward, by a woman with a masters in public health, discusses the importance of menstruation to women’s cultural and emotional identity. Although it is thus oddly spiced with social science, this book has a strong biomedical perspective that menstruation is “needless”(p. 159) and “harmful”(p. 5) 3. This is not new. Similar cultural notions are part of our daily lives as women – menopause needs “replacement” hormone therapy, successful pregnancy and delivery need hormonal or surgical intervention and PMS is a disease well treated by Prozac & Mac 226;26. Much of women’s lives, especially the reproductive aspects, are viewed as a disease or deficiency state. Should it surprise us that menstruation, too, is perceived this way?

Women who have the most difficulty with their cycles are adolescent and perimenopausal women. In both, high estrogen levels and ovulation disturbances are common 13,27. Most menstrual cycle related problems (heavy flow, premenstrual symptoms, cyclic migraines, breast nodularity and pain and even severe cramps), like endometrial hyperplasia and cancer, are related to abnormal cycles. Their root cause is too little progesterone for the level of estrogen 22. Paradoxically, this book proposes to get rid of menstrual flow by giving the high dose estrogen and progestin therapy in oral contraceptives. You should be aware that, although newer contraceptives are called “low dose,” even the 20-35 microgram estrogen pills provide estrogen levels approximately four times natural, menstrual cycle levels.

I think it is perfectly acceptable and feasible to continue a conventional oral contraceptive pill for an additional week or two. Camping in bear country is a good reason given that menstrual blood may cause aggression in these wild animals. This should be an exception, not the rule. I have significant doubts about the feasibility and safety of continuous birth control pills. Progesterone and progestins, given continuously, cause a thinning of the endometrium (uterine lining) so there is little or nothing to shed as a period. However, continuous birth control pills provide high estrogen and progestin levels that usually thicken the endometrium. There is a high risk of irregular bleeding and the three-monthly flow is likely to be heavy and miserable. Unpredictable flow is a hundred times worse than cyclic ovulatory menstruation. Breast soreness is also likely and nausea, weight gain and fluid retention in some women would likely be magnified by daily therapy. In the real world, sore or nodular breasts (which raise the specter of breast cancer) and spotting or irregular flow (causing worries about endometrial cancer) will lead to skipped pills 28 and lost contraceptive effectiveness.

I’m also peeved at the about-face of medical experts who, in the ’80s, blamed women for exercising and skipping periods. They are now telling us to use excessive exercise (under a doctor’s orders) or daily birth control pills to produce amenorrhea 3!

Ironically, we don’t even know the normal variability of menstrual cycles of populations of women of different ages. We need long term information about women’s cycles just after menarche, in their 20s, 30s, 40s and entering perimenopause. However, doing the longitudinal population based studies that would provide this information is not a priority for research granting bodies. I would like to know how many such proposals have been rejected by the Medical Research Council of Canada (MRC) and the U.S. National Institutes of Health. (I know of several on which I wasted months of work). To achieve health for women we need this information because silent ovulatory disturbances (in regular cycles with normal estrogen levels) are associated with significant bone loss [8]. To date, that study we began 15 years ago is the only one to systematically and continuously document menstruation and ovulation over a year in a large number (66) of women. Given that the new Canadian Health Research Institutes (a replacement for MRC) is apparently not to have a Women’s Health Institute, these crucial but expensive studies may never be done. Furthermore, 86% of Canadian premenopausal women have used the birth control pill for three or more months (Prior, unpublished data from the Canadian Multicentre Osteoporosis Study, 1998). Therefore, we may never know what is truly normal (in other words, for women not exposed at a young age to high and suppressive estrogen/progestin levels).

Instead of suppressing periods, we should learn more about, and treat, ovulation disturbances. Our studies show that ovulation disturbances are common and occur in over 35% of regular cycles in healthy women [29]. Worry, such as concern about gaining weight, or feeling you need to restrict food (although your weight is normal) is related to ovulation disturbances [29-31]. Worry about eating is also associated with higher cortisol production and potential bone risk [32]. In addition, disturbed ovulation with adequate or high estrogen levels is related to a significant increased risk for breast cancer [33-35]. Finally, we now know that PMS is caused by estrogen excess or inadequate progesterone levels [36]. Recognizing, first, and then treating ovulatory disturbances (with cyclic progesterone or medroxyprogesterone “replacement”) until the root cause is corrected [22,23] would fix problems blamed by Coutinho and Segal on periods.

In summary, I believe that the amazing interplay of many hormones creating the ovulatory menstrual cycle is important for far more than making babies. Ovulatory menstrual cycles teach us as women to be adaptable and to tune into what is really important. We learn to adjust our lives and responses to our changing internal environment. This greater flexibility serves our culture well by helping us cope, for example, with the fulfilling chaos of raising children. It also allows us to be adaptable and therefore more able to resolve conflicts. In addition, normal menstrual cycles potentially allow us to feel in touch with environmental rhythms and also serve as a reminder that freedom from worry as well as lack of illness are necessary for health. When we don’t understand the whole, it is wise to collaborate with rather than seek conquest of nature. Therefore, my response to women offered the “opportunity” of no periods is to be cautious. I personally, recommend women “Go with the flow!”

Jerilynn Prior is a Professor of Endocrinology at the University of British Columbia and an internationally known expert on ;women’s health.

References

  1. Spender D. For the Record. London: The Women’s Press Ltd., 1985.
  2. Asbell B. The Pill – A biography of the drug that changed the world. First ed. New York, New York: Random House Inc., 1995.
  3. Coutinho EM, Segal SJ. Is menstruation obselete. New York: Oxford University Press, 1999.
  4. Gladwell M. John Rock’s error. The New Yorker 2000; (March 13).
  5. Thomas SL, Ellertson C. Nuisance or natural and healthy: should monthly menstruation by optional for women? Lancet 2000; 355:922-924 (essay).
  6. Prior JC, Ho Yeun B, Clement P, Bowie L, Thomas J. Reversible luteal phase changes and infertility associated with marathon training. Lancet 1982; 1:269-270.
  7. Prior JC. Endocrine “conditioning” with endurance training: a preliminary review. Can.J.Appl.Sport Sci. 1982; 7:149-157.
  8. Prior JC, Vigna YM, Schechter MT, Burgess AE. Spinal bone loss and ovulatory disturbances. NEJM 1990; 323:1221-1227.
  9. Bonen A. Recreational exercise does not impair menstrual cycles: a prospective study. Int.J.Sports Med. 1992; 13:110-120.
  10. Rogol AD, Weltman A, Weltman JY, Serp RI, Snead DB, Levine S, et al. Durability of the reproductive axis in eumenorrheic women during one year of endurance training. J.Appl.Physiol. 1992; 72:1571
  11. Lee RB. The !Kung San: men, women and work in a foraging society. London: Cambridge University Press, 1979.
  12. Prior JC, Vigna YM, Schulzer M, Hall JE, Bonen A. Determination of luteal phase length by quantitative basal temperature methods: validation against the midcycle LH peak. Clin.Invest.Med. 1990; 13:123-131.
  13. Vollman RF. The menstrual cycle. In: Friedman EA, editor. Major Problems in Obstetrics and Gynecology, Vol 7. 1 ed. Toronto: W.B. Saunders Company, 1977:11-193.
  14. Doring GK. The incidence of anovular cycles in women. J.Reprod.Fertil. 1969; (Suppl 6):77-81.
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  17. Santoro N, Rosenberg J, Adel T, Skurnick JH. Characterization of reproductive hormonal dynamics in the perimenopause. J.Clin.Endocr.Metab. 1996; 81:4,1495-1501.
  18. Prior JC. Perimenopause: The complex endocrinology of the menopausal transition. Endocr.Rev. 1998; 19:397-428.
  19. Ramcharan S, Love EJ, Frick GH, Goldfien A. The epidemiology of premenstrual symptoms in a population based sample of 2,650 urban women: attributable risk and risk factors. J.Clin.Epidemiol. 1992;
  20. Prior JC, Vigna YM, Alojado N, Sciarretta D, Schulzer M. Conditioning exercise decreases premenstrual symptoms: a prospective controlled six month trial. Fertil.Steril. 1987; 47:402-408.
  21. Thys-Jacobs S, Starkey P, Bernstein D, Tian J, The Premenstrual Synrome Study Group. Calcium carbonate and the premenstrual syndrome: effects on premenstrual and menstrual symptoms. Am.J.Obstet.Gynecol. 1998; 179:444-452.
  22. Prior JC. Ovulatory disturbances: they do matter. Can.J.Diagnosis 1997; February:64-80.
  23. Prior JC, Vigna YM, Barr SI, Rexworthy C, Lentle BC. Cyclic medroxyprogesterone treatment increases bone density: a controlled trial in active women with menstrual cycle disturbances. Am.J.Med. 1994; 96:521-530.
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  25. Laws S. Issues of blood – the politics of menstruation. London: MacMillan Press Ltd, 1990.
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  27. Baird DT. Anovulatory dysfunctional uterine bleeding in adolescence. In: Flamigni C, Verturolil S, Givens JR, editors. Adolescence in females. Chicago: Year Book Medical Publishers, Inc., 1985:273-285.
  28. Kaufert PA. The menopausal transition; the use of estrogen. Can.J.Publ.Health. 1986; 77 (Suppl 1):86-91.
  29. Barr SI, Janelle KC, Prior JC. Vegetarian versus nonvegetarian diets, dietary restraint, and subclinical ovulatory disturbances: prospective six month study. Am.J.Clin.Nutr. 1994; 60:887-894.
  30. Schweiger U, Tuschl RJ, Platte P, Broocks A, Laessle RG, Pirke KM. Everyday eating behavior and menstrual function in young women. Fertil.Steril. 1992; 57:771-775.
  31. Barr SI, Prior JC, Vigna YM. Restrained eating and ovulatory disturbances: possible implications for bone health. Am.J.Clin.Nutr. 1994; 59:92-97.
  32. McLean JA, Barr SI, Prior JC. Cognitive dietary restraint is associated with higher urinary cortisol excretion in healthy premenopausal women. Am J. Clin Nutrition 2000.
  33. Coulam CB, Annegers JF, Kranz JS. Chronic anovulation syndrome and associated neoplasia. Obstetrics and Gynecology 1983; 61:403-407.
  34. Cowan LD, Gordis L, Tonascia JA, Jones GE. Breast cancer incidence in women with a history of progesterone deficiency. Am.J.Epidemiol. 1981; 114:209-214.
  35. Chang KJ, Lee TTY, Linares-Cruz G, Fournier S, de Lignieres B. Influence of percutaneous administration of estradiol and progesterone on human breast epithelial cell cycle in vivo. Fertil.Steril. 1995; 63:785-791.
  36. Wang M, Seippel L, Purdy RH, Backstrom T. Relationship between symptom severity and steroid variation in women with premenstrual syndrome: Study on serum pregnenolone, prenenolone sulfate, 5a-Pregnane-3,20-Dione, and 3a-Hydroxy-5a-Pregnan-20-one. J.Clin.Endocr.Metab. 1996; 81:1076-1082.

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Board Members: Dr. Keith Dawson, Dr. Jason Kong, Dr. Ehud Ur, Dr. Jerilynn Prior, Dr. Tom Elliott, Dr. Breay Paty, Dr. Sandra Sirrs

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