Talk:Menstrual cycle

Citation 59

I thought you all checked all these sources? Can I timestamp this? — Preceding unsigned comment added by 98.234.94.99 (talk) 19:47, 19 March 2013 (UTC)

Strike The Moon-Tales

I think strictly, mathematically, speaking, the fact that a lunar cycle is 28 days, combined with this variable "science", logic dictates that there might be one (or realistically several) women that speak or read English have a cycle that closely mimics a lunar cycle.

Strike all the illogical, erroneous moon-tales from this article. They are unsupported. The lunar phase of the urban legend even contradicts tales mentioned in one of the links mentioning moon-phases. The other moon-link is useless as well as it drops you at a search and not a specific reference.

You call this Space Age Medicine? Hmmmmppft72.251.0.19 09:41, 10 May 2007 (UTC)— Preceding unsigned comment added by 72.251.0.19 (talk • contribs) 09:41, 10 May 2007 (UTC)

I agree about this. I do think it's a good point that perhaps the reason that the moon doesn't seem to affect modern women's menstrual cycles is because of the urban lifestyle. But the point seems moot, as either way the moon doesn't seem to have anything to do with modern menstrual entrainment. I'm not sure what procedure policy dictates for removal of this section, but if someone knows then I think it would be well-advised to move forward with removing this section. Ehb 17:55, 4 June 2007 (UTC)— Preceding unsigned comment added by Ehb (talk • contribs) 4 June 2007 (UTC)

As a matter of fact, the influence of the moon on menstrual cycles is known. It's very simple: light affects the pituitary. However, in order to get enough light to stimulate ovulation, women must be not only in non-urban environments but *always sleeping outdoors*. There used to be a research abstract about a study done on this (women with irregular cycles slept with the light on - it needs a lot of light, I have no idea how they managed to sleep - for three days when they should be ovulating, and this generally regulated their cycle length) at the Apollo Health website, but for some reason they have less information up at the moment, although there is some at http://www.apollolight.com/irregular_menstrual_cycle.html (now with a fair amount of information I'd mistrust, unfortunately, such as the theory that women not on the Pill are naturally in phase with the moon, but I think the original study was still valid - can anyone find it?). Anyway, this is a real relationship between lunar cycles and menstrual cycles, and I'm guessing it would have been influential during evolution, but since humans have been living indoors for a very long time now, and with enough light pollution that the moon makes little difference to the amount of nighttime illumination, this no longer affects women's cycles. Anyone who is living a modern urban life and thinks that the moon is affecting their cycles, libido or anything else is living in dreamland. As far as I can tell, this would be a suitable section for the article:

The average menstrual cycle is 29 days, the same length as the lunar cycle. When humans were still living and sleeping outdoors, with no light pollution to obscure moonlight, it is probably that the full moon coincided with ovulation, since light stimulates the pituitary, and that this will have been relevant during evolution. Some studies have shown that sleeping with a strong light on (at least 50W three feet away from the bed) for three days at the time of expected ovulation can regulate the length of irregular or long cycles. However, since modern humans sleep indoors and there is so much light pollution that the moon makes little to no difference to the amount of nighttime illumination, lunar cycles now make absolutely no difference to menstrual cycles. There are various myths around that the moon can influence fertility, libido or cycle length, but they are all incorrect as applied to modern lifestyles. Strong light can indeed alter circadian rhythms and menstrual cycles, which is why shift workers are prone to menstrual irregularities, and bright light therapy (as used for Seasonal Affective Disorder or depression) in the daytime may also affect menstrual cycles.

I'm having trouble finding research, Google searches keep pulling up all the nonsense myths instead. Here's the best I can do so far, sorry that they're abstracts rather than full articles:

http://www.informaworld.com/smpp/content~content=a714014296~db=all

http://www.ncbi.nlm.nih.gov.ncoimage.neco.edu/pubmed/17601857?dopt=Abstract

http://www.ncbi.nlm.nih.gov.ncoimage.neco.edu/pubmed/17597228?dopt=Abstract

http://www.ncbi.nlm.nih.gov.ncoimage.neco.edu/pubmed/17290302?dopt=Abstract

Elettaria (talk) 13:03, 21 January 2008 (UTC)— Preceding unsigned comment added by Elettaria (talk • contribs) 13:03, 21 January 2008 (UTC)

The medical consensus seem to be that it's just a coincidence. I'm removing the association made in the article.

http://academic.evergreen.edu/curricular/astro/astro2001/projects/luna/menstruation/mencycle.htm http://skeptics.stackexchange.com/questions/2056/is-the-human-menstrual-cycle-related-to-the-lunar-cycle http://www.straightdope.com/columns/read/1348/whats-the-link-between-the-moon-and-menstruation Mihaiam (talk) 20:04, 19 October 2012 (UTC)

The sources cited above are from 2 Internet forums and a 2001 dated blog for a state college's Astronomy class, in my opinion none of these would be considered reliable sources for a medical consensus re: a possible (or not-possible) lunar correlation. Shearonink (talk) 20:35, 19 October 2012 (UTC)

phases of menstruation cycle.

There are 4 phases of menstrual cycle which includes: (A)PROLIFERATIVE PHASE;This is also known as post menstrual phase,pre-ovulatory phase or proliferative phase. It starts on the 4th day after menstruation and continues upto the 14th day. It is characterised by mucous secretions and the body prepares itself for ovulation. The changes that occurs in this phase are controlled by hormone progesterone.

(b) SECRETORY PHASE:This is also known as post ovulatory or pre-menstrual phase. It takes place from the 15th day to the 28th day. Characterised by thickening of the endometrium,increased production of mucus,vascuralisation of thu uterine ligning and the body is ready for implantation of the fertilsed ova.

(C) MENSTRUAL PHASE: This is the last phase of menstrual cycle. It takes place after the ova has not been fertilised after a period of tim e. There is vasoconstriction of the blood vessels taking blood to the endometrium. This results in necrosis of the endometrium. The non-functional non vascuralised endometrium is shed off together with tfhe unfertilised ova as the menstrusl flow.

CONTENTS OF THE MENSTRUAL FLUID: It consists of; -Mucin. -Blood. -Debris of the endometrium. -Unfertilised ova. -Some lymphocytes.— Preceding unsigned comment added by 196.202.206.37 (talk • contribs) 14:38, 23 January 2009

women in groups myth

Is there any research supporting the notion of menses of females in groups converging ?— Preceding unsigned comment added by Tumadoireach (talk • contribs) 05:02, 17 March 2011

Title of this page

I was doing some studying about the 'menstrual cycle' and found this in Guyton's Textbook of Medical Physiology (chapter 81):

"The normal reproductive years of the female are characterized by monthly rhythmical changes in the rates of secretion of the female hormones and corresponding physical changes in the ovaries and other sexual organs. This rhythmical pattern is called the female monthly sexual cycle (or, less accurately, the menstrual cycle)."

So I'd like to request a name change for this page to sexual cycle, since that would be scientifically correct. Zaheer12a (talk) 21:51, 29 January 2012 (UTC)

I don't see how "menstrual cycle" is less scientifically correct. And in any case, the title you propose is not the WP:COMMONNAME; nor does it pass Wikipedia:MEDMOS#Naming conventions. 37.59.65.55 (talk) 18:31, 9 October 2012 (UTC)

Contradictory statements on lunar effect

At the bottom of the Menstrual_cycle#Length section there are statements supporting a Lunar effect on menstrual cycles:

A 1979 study of 305 women found that approximately one-third of the subjects had lunar period cycles in length, i.e., a mean cycle length of 29.5 days plus or minus 1 day. Almost two-thirds of the subjects started their cycle in the brighter half of the lunar cycle, significantly more than would be expected by random distribution. Another study found a statistically significant number of menstruations occurred around the new moon.

However, in the "Nightlighting and the moon" section it says:

A meta-analysis of studies from 1996 showed no correlation between the human menstrual cycle and the lunar cycle. Dogon villagers did not have electric lighting and spent most nights outdoors, talking and sleeping; so they were an ideal population for detecting a lunar influence; none, however, was found.

I think the latter has more evidence, since it is a meta-analysis that was done more recently, and therefore I suggest that the text in the former box should be removed from the article. Mikael Häggström (talk) 16:50, 15 March 2013 (UTC)

Thanks for your quick response! A couple of moons ago I did look into this quite deeply but have since forgotten anything that I learned. I do remember that any information is quite questionable. Please give me some time to again become familiar with your new suggestions. For now, Gandydancer (talk) 17:11, 15 March 2013 (UTC) err...actually it was quite a few moons ago... Gandydancer (talk) 17:13, 15 March 2013 (UTC)

OK, ref #1 Straight Dope is out because they claimed incorrectly that a normal period is 28d.

The pubmed studies say:

ref#2:

Abstract

In a selected population of 312 women, prospective menses records were maintained during the autumn of 1977. Women whose menstrual cycle duration approaches the cycle duration of the earth's moon (29.5 days) tend to ovulate in the dark phase of the lunar period. The dark phase encompasses the half-cycle of the month from last quarter, through new moon, to first quarter. Women showing irregular menses also tended to ovulate during the dark phase of the lunar period. PIP:

The possibility of a lunar effect on the menstrual cycle was investigated in 312 university students who kept records of their menstrual cycles. These records were studied for 14 weeks in a double-blind, prospective manner. Of the 312 women, 68 experienced lunar period cycles (29.5 days). Of these 68, 47 menstruated in the light half of the month; therefore, ovulation tended to occur in the dark phase of the lunar period which is defined as the half-cycle of the month from the last quarter, through new moon, to first quarter. Even women with irregular menses (defined for this study as appreciably varied from the 29.5-day lunar cycle) also tended to ovulate during the dark phase of the lunar period. One possible explanation is that a natural rhythm of electromagnetic radiation has its origin in the lunar cycle and may be reflected in phase-locking of the human menstrual cycle.

ref #3

PIP:

A double-blind, prospective study during the fall of 1979 investigated the association between the menstrual cycles of 305 Brooklyn College undergraduates and their associates and the lunar cycles. All subjects were 19-35 years old and using neither OCs (oral contraceptives) nor the IUD. Approximately 1/3 of the subjects had lunar period cycles, i.e., a mean cycle length of 29.5 +/- l day. Almost 2/3 of the subjects started their October cycle in the light 1/2 of the lunar cycle, significantly more than would be expected by random distribution. The author concludes that there is a lunar influence on ovulation.

ref #4

PIP:

A synchronous relationship between the menstrual cycle and lunar rhythm was confirmed by investigative data, laboratory findings, and clinical experience. Among the 826 female volunteers with a normal menstrual cycle (ages 16-25), a large proportion of menstruations occurred around the new moon (28.3%), while at other times during the lunar month, the proportion of menstruations occurring ranged between 8.5-12.6%; the difference was significant (P0.01). The 6-hydroxymelatonin levels in the urina sanguinis of 3 female volunteers reached their zenith prior to and during menstruation, gradually declining to their nadir during ovulation. The difference in 6-hydroxymelatonin between menstruation and ovulation was significant (P0.01). 2 of these 3 volunteers had their zenith in the period of the new moon and nadir 3-4 days prior to the full moon respectively. The lunar-menses-regulatory therapy in treatment of Nephropenic secondary amenorrhea revealed 4 clinical cures, 5 marked effects, 8 menogogue, and 3 ineffective out of 20 cases. (1986)

ref #5

Abstract

Human and animal physiology are subject to seasonal, lunar, and circadian rhythms. Although the seasonal and circadian rhythms have been fairly well described, little is known about the effects of the lunar cycle on the behavior and physiology of humans and animals. The lunar cycle has an impact on human reproduction, in particular fertility, menstruation, and birth rate. Melatonin levels appear to correlate with the menstrual cycle. Admittance to hospitals and emergency units because of various causes (cardiovascular and acute coronary events, variceal hemorrhage, diarrhea, urinary retention) correlated with moon phases. In addition, other events associated with human behavior, such as traffic accidents, crimes, and suicides, appeared to be influenced by the lunar cycle. However, a number of reports find no correlation between the lunar cycle and human reproduction and admittance to clinics and emergency units. Animal studies revealed that the lunar cycle may affect hormonal changes early in phylogenesis (insects). In fish the lunar clock influences reproduction and involves the hypothalamus-pituitary-gonadal axis. In birds, the daily variations in melatonin and corticosterone disappear during full-moon days. The lunar cycle also exerts effects on laboratory rats with regard to taste sensitivity and the ultrastructure of pineal gland cells. Cyclic variations related to the moon's phases in the magnitude of the humoral immune response of mice to polivinylpyrrolidone and sheep erythrocytes were also described. It is suggested that melatonin and endogenous steroids may mediate the described cyclic alterations of physiological processes. The release of neurohormones may be triggered by the electromagnetic radiation and/or the gravitational pull of the moon. Although the exact mechanism of the moon's influence on humans and animals awaits further exploration, knowledge of this kind of biorhythm may be helpful in police surveillance, medical practice, and investigations involving laboratory animals.

And source #6 does not agree: "The Moon Was Full and Nothing Happened" [1]

I'm going to go with the PubMed articles rather than one that, like Straight Dope, has the 28d problem and goes on to say The light of the moon is a very minor source of light in most women's lives, and is no more likely than the moon's gravitational force to have a significant effect on a woman's ovulation. Furthermore, the average menstrual cycle is 28 days but varies from woman to woman and month to month, while the length of the lunar month is a consistent 29.53 days.' It seems that these authors are not even aware that even clams feel the moon effect when put in a box that does not allow "the light of the moon". Gandydancer (talk) 17:48, 16 March 2013 (UTC)