# Onset of Menses - average age? **URL:** \ **Category:** Factual Questions\ **Created:** [June 25, 2012, 11:29am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233 "2012-06-25T11:29:40Z")\ **Posts on this page:** 17\ **Page:** 1
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [June 25, 2012, 11:29am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/1 "2012-06-25T11:29:40Z")
OK, so I have read a few reliable reports about menses beginning earlier in some girls, and NIH investigating. But a Mom (intelligent, laid back, vaccinates her kids on schedule . . .) says that her Pediatrician told her the average age of onset is now 7.5 to 9 years old. :eek:šŸ˜• What?!? šŸ˜•:eek: Talk me down guys. Does anyone have any reliable statistics, or know where I can find some? Because if Iā€™m going to have to face this in the next three years Iā€™ll need to start preparing right the frack now. I donā€™t even know how this is possible. I mean for that to be the average age, would mean that some girls must be starting earlier. Again, Iā€™ve read about ā€œpocketsā€ of girls who were starting in the 7-9 range, but this was considered odd enough to warrant an environmental investigation. Say it ainā€™t so. And gimme a cite, please? ---
**Author:** ![Musicat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/musicat/32/20189_2.png) [@Musicat](https://boards.straightdope.com/u/Musicat)\ **Post date:** [June 25, 2012, 11:39am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/2 "2012-06-25T11:39:08Z")
Have you tried googling ā€œonset of mensesā€? [Menarche](http://en.wikipedia.org/wiki/Menarche) > [@](#): > > Some estimates suggest that the median age of menarche worldwide is 14, and that there is a later age of onset in Asian populations compared to the West. The average age of menarche is about 12.5 years in the United States, 12.72 in Canada, 12.9 in the UK and 13.06 Ā± 0.10 years in Iceland. A study on girls in Istanbul, Turkey, found the median age at menarche to be 12.74 years. IANAD, but 7 years seems much too soon, at least for an _average._ Thatā€™s first grade, fer chrissakes. I donā€™t seem many first graders walking around with boobs. There are references in the Wiki article. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 25, 2012, 12:01pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/3 "2012-06-25T12:01:01Z")
Thatā€™s the current age for breast development to begin, which _has_ moved up significantly in the last several decades. Onset of periods (menarche) not so much so. [Your cite.](http://pediatrics.aappublications.org/content/118/5/2245.full) > [@](#): > > From the early 1800s to the mid-1950s, menarche occured at increasingly younger ages in the United States, but there has been no further decline in the last 40 to 50 years. This finding also has been seen in international studies of other developed urban populations.2 The US National Health and Nutrition Examination Surveys have found no significant change in the median age at menarche over the past 30 years except among the non-Hispanic black population, which has a 5.5-month earlier age at menarche than it did 30 years ago.3 Age at menarche varies internationally and especially in less developed countries; in Haiti, for example, the mean age at menarche is 15.37 years.4, 5 This knowledge may be especially pertinent for practitioners with a large number of immigrant families in their patient population. Although onset of puberty and menarche typically occur at a later age in females from less well-developed nations, 2 large studies have confirmed that a higher gain in body mass index (BMI) during childhood is related to an earlier onset of puberty.6, 7 This earlier onset of puberty may result from attainment of a minimal requisite body mass at a younger age. Other possible explanations for the perceived trend in timing and progression of puberty are environmental factors, including socioeconomic conditions, nutrition, and access to preventive health care.8 > > Despite variations worldwide and within the US population, median age at menarche has remained relatively stable, between 12 and 13 years, across well-nourished populations in developed countries. The median age of females when they have their first period or menarche is 12.43 years ā€¦ ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [June 25, 2012, 12:08pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/4 "2012-06-25T12:08:48Z")
This is one of those topics where your research numbers are going to be a little bit behind what doctors are actually seeing. That is, doctors see these girls and collect data, which is later interpreted by researchers, so theyā€™re always a little behind the curveball. As of 2003, the average age of menarche in the US was somewhere between 12 and 13, depending on what study youā€™re looking at and what population youā€™re looking at. This was only 3 months younger than reported in 1973. Fewer than 10% of girls in 2003 got their period before age 11. [Changing Biology: Age at First Menstruation - Sociological Images](http://thesocietypages.org/socimages/2008/09/19/changing-biology-age-at-first-menstruation/) [Age at menarche and racial comparisons in US girls - PubMed](http://www.ncbi.nlm.nih.gov/pubmed/12509562) Now, and this came as a total shock to me, 2003 was almost 10 years ago! In those 10 years, weā€™ve seen a lot more fat kids, and girls with more body fat tend to get their periods sooner. Weā€™ve also seen a rise in the percentage of non-white girls as a total of our population of girls, and they tend to get their first periods a little sooner than other girls. So itā€™s entirely possible that the average age has dropped a little more since 2003. But if itā€™s dropped by five _years_, Iā€™d be exceedingly surprised. Thatā€™s how much menarche dropped between starving peasants in feudal Europe (17 years) and well-nourished 21st century. Thatā€™s an incredible lot. That falls into the ā€œextraordinary claimsā€ category - Iā€™d ask that doctor what studies heā€™s basing his statement on. His claim, heā€™s got to support it. That being saidā€¦yes, you do have to talk to her sooner than you think, if you were waiting until sheā€™s 12 or starts bleeding to start The Talk. ā€œThe Talkā€ is rather passe, anyhow, and itā€™s generally recommended that you have many small Talks, beginning in early childhood, keeping an open dialogue of age-appropriate information. Most parents who plan one The Talk end up doing it far too late, after their kids have all sorts of nonsense in their heads (and sometimes babies in their bodies!) from their classmates. Itā€™s actually much easier on you both to have many small talks than one long embarrassing lecture. If you need some tips on how to broach the topic(s), I quite like this guide: [Answering Questions About Sex (for Parents) - Nemours KidsHealth](http://kidshealth.org/parent/positive/talk/questions_sex.html) By 6, most kids are ready for sperm-and-egg-make-a-baby level of information, as well as, ā€œboys and girls have different body parts and we donā€™t let anyone touch anything covered by a bathing suit unless itā€™s a doctorā€ and ā€œwe donā€™t have to keep bad touches a secret; that secret is okay to tellā€. One of my favorite books to introduce hard topics is called [Itā€™s Not the Stork!](http://www.amazon.com/Its-Not-Stork-Families-Friends/dp/0763600474) It covers not only sexual stuff, but bullying/how to be a good friend, the range of what families look like, etc. Itā€™s a fantastic book to read with your kid and start those difficult conversations. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [June 25, 2012, 2:51pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/5 "2012-06-25T14:51:38Z")
From what Iā€™m seeing, it seems that while itā€™s not an average, 7-15 is the new ā€œnormalā€ range. i.e. If a child starts at 7 it doesnā€™t prompt an investigation into the cause. But I donā€™t have access to the actual studies, only the blogified summaries - which I find extremely unsatisfying. Iā€™d like to see some real data, or at least primary information. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 25, 2012, 7:51pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/6 "2012-06-25T19:51:11Z")
Huh? Menarche at age 7 is without question very abnormal. It is early even for breast development. Most of us peds would still at least make sure that the 7 year old with breast development is not also suddenly shooting up the growth chart (which would further raise the issue of true precocious puberty) and/or does not also have pubic hair onset. If so weā€™d likely still proceed further. Menarche then? Very abnormal. If that review from the American Academy of Pediatrics, Committee on Adolescence, American College of Obstetricians and Gynecologists, Committee on Adolescent Health Care and its long list of references does not satisfy your desire for ā€œreal dataā€ I donā€™t know what will. Maybe Iā€™m on ignore? Itā€™s possible. But then why no acknowledgement of **WhyNot** ā€™s articles, including a comprehensive cite of primary data: ā€œAge at menarche and racial comparisons in US girlsā€? Both of us on ignore? Doubt it. Another link that may help is [webmd](http://children.webmd.com/causes-symptoms): > [@](#): > > Girls who show significant signs of puberty and its progression before age 8 and boys before age 9 are considered precocious. About 1 out of 5,000 children are affected. ā€¦ Many experts say that, on average, puberty is starting earlier in the U.S. than it did in the past. The average age of menstruation has stayed roughly the same. Yet studies suggest that early signs ā€“ like breast development ā€“ are happening a year earlier than they did decades ago. ā€¦ Menstruation (typically not until two to three years after the earlier symptoms start) ā€¦ **WhyNot** , well I appreciate your post! I notice that ā€œItā€™s Not the Stork!ā€ is done by the same team that did [ā€œItā€™s Perfectly Normalā€](http://www.amazon.com/Its-Perfectly-Normal-Changing-Growing/dp/1564021599) which I heartily recommend for later middle school on - parents should definitely read it on their own first to make sure they are comfortable with it. I think that somewhere from the doc saying something to being asked here there was a confusion regarding a mention of the drop in the _onset of puberty_, as marked by _thelarche_ (onset of breast development) and _onset of menses_ (menarche). My WAG is that the long scale drop in age of menarche was a return to species norms as nutritional status improved (the same happened with heights) whereas the earlier thelarche is function of both created chemicals functioning as ā€œendocrine disruptorsā€ and obesity. Anecdotally we are also seeing a greater percent of males with more significant degrees of male breast development with puberty (male gynecomastia, a normal occurrence in general that usually goes away in 1 to 3 years, but again, seeing it more commonly and to a greater degree) ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 25, 2012, 8:20pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/7 "2012-06-25T20:20:59Z")
> [@DSeid](#): > > ā€¦ a return to species norms as nutritional status improved (the same happened with heights) ā€¦ This statement might cause some raised eyebrows so I figured Iā€™d preemptively back it up. Not available free online but the article I am quoting is [Science 4 May 2012: Vol. 336 no. 6081 pp. 538-539](http://www.sciencemag.org/content/336/6081/538.2.summary) DOI: 10.1126/science.336.6081.538-b : > [@](#): > > Modern humans have gone through a lot of changes in the past 30,000 years. We switched from hunting and gathering to farming and herding; from life as nomads to settling in urban centers; from eating meat, nuts, and tubers to consuming grains, sugars, and dairy products. Now, a remarkably comprehensive analysis of more than 2000 European skeletons presented at the meeting reveals how these cultural changes have altered our physiques ā€¦ this is the first systematic study of how the skeleton changed from the time modern humans spread through Europe 30,000 years ago until they were circling the globe in jets by the 1960s ā€¦ > > ā€¦ As for overall height, about 30,000 years ago, European men stood 1.72 meters tall, almost as tall as Europeans today. Their height and weight dropped steadily until 4000 years ago, probably because of poorer nutrition and health, particularly with the advent of agriculture 10,000 years ago. With a few exceptionsā€”for example, milk-drinking Scandinaviansā€”Europeans got even shorter during the Medieval period and stayed short until 1900. ā€¦ I know that it is a huge digression but again it supports the concept. Height came _back_ to Paleolithic norms in the last hundred years and leveled off at that point in the last decades. Along that same time menarche dropped to a median of about 12.5 and leveled off at in the same time course. Thelarcheā€™s change has followed a different course. ---
**Author:** ![Hilarity\_N.Suze](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/hilarity_n.suze/32/6223_2.png) [@Hilarity\_N.Suze](https://boards.straightdope.com/u/Hilarity_N.Suze)\ **Post date:** [June 25, 2012, 8:39pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/8 "2012-06-25T20:39:06Z")
You know that ā€œaverageā€ covers things like the 8-year-old and also things like the 16-year-old, right? If I had a daughter, I think I would have started preparing her early enough to cover all of it, just so she wouldnā€™t be freaked out if she happened to be in the early part of the range. But then, the topic will come up much earlier if there is a functioning female (i.e., right age, no hysterectomy, no period-suppressing drugs) as there will be supplies, and kids will find them. Okay, are you talked down yet? Has she seriously never found your box of tampons and poured them into the toilet to see if theyā€™ll expand? Or seen TV ads for feminine products? Or heard you bitching about one thing or another? Because I had sons, and by the time they were 5 or 6 they knew that certain things went on with moms and other women, and hands off the stuff. I was just as specific as I had to be (ā€œNo, those are not candlesā€) but would have been more specific with a daughter, Iā€™m sure. ---
**Author:** ![Lasciel](https://avatars.discourse-cdn.com/v4/letter/l/e79b87/32.png) [@Lasciel](https://boards.straightdope.com/u/Lasciel)\ **Post date:** [June 25, 2012, 8:51pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/9 "2012-06-25T20:51:17Z")
So, as someone on the ā€œstarving peasantā€ end of things (thanks, WhyNot), are there any health benefits or deficits due to starting menses statistically late in life? My mother, aunt, and grandmother all started very late also, so Iā€™m betting that if I have a girl eventually, thereā€™s a chance sheā€™ll be a late bloomer also. Have to say that I prefer that to starting at 7. Christ, that would be horrid to deal with as a little kid. ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [June 25, 2012, 9:09pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/10 "2012-06-25T21:09:22Z")
> [@DSeid](#): > > . . . > > If that review from the American Academy of Pediatrics, Committee on Adolescence, American College of Obstetricians and Gynecologists, Committee on Adolescent Health Care and its long list of references does not satisfy your desire for ā€œreal dataā€ I donā€™t know what will. > > Maybe Iā€™m on ignore? Itā€™s possible. But then why no acknowledgement of **WhyNot** ā€™s articles, including a comprehensive cite of primary data: ā€œAge at menarche and racial comparisons in US girlsā€? Both of us on ignore? Doubt it. Sorry about that! When I saw ā€œYour Citeā€ I thought you were re-linking the above one. Thatā€™s exactly what we needed. Thanks all of you! Iā€™ve forwarded the info to my friend as well. I promise you sheā€™ll make sure the Dr. sees the info. LOL! ---
**Author:** ![Loach](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/loach/32/350_2.png) [@Loach](https://boards.straightdope.com/u/Loach)\ **Post date:** [June 25, 2012, 9:20pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/11 "2012-06-25T21:20:55Z")
One data point which popped up in my household this week is that it happens at 12.5 years old. Dammit. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 25, 2012, 10:06pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/12 "2012-06-25T22:06:43Z")
> [@Lasciel](#): > > ā€¦ are there any health benefits or deficits due to starting menses statistically late in life? Several potentially. 1. Possibly less risk of breast cancer. 2. Longer to grow. The growth spurt hits from a higher starting point. 3. Avoidance of attention as a sexual being earlier than emotionally prepared for. Of course offset by the not being as developed as her friends envy. Not being too far off from the median is always easiest, given how mean some kids are, but I think kids are meaner to the early bloomer than to the girl who is late. And the attention of older boys can cause real problems ā€¦ > [@TruCelt](#): > > Sorry about that! When I saw ā€œYour Citeā€ I thought you were re-linking the above one. Thatā€™s exactly what we needed. ā€¦ No worries. ---
**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\ **Post date:** [June 25, 2012, 10:25pm UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/13 "2012-06-25T22:25:25Z")
> [@DSeid](#): > > **WhyNot** , well I appreciate your post! I notice that ā€œItā€™s Not the Stork!ā€ is done by the same team that did [ā€œItā€™s Perfectly Normalā€](http://www.amazon.com/Its-Perfectly-Normal-Changing-Growing/dp/1564021599) which I heartily recommend for later middle school on - parents should definitely read it on their own first to make sure they are comfortable with it. Thanks! Iā€™ll check that one out myself. > [@Lasciel](#): > > So, as someone on the ā€œstarving peasantā€ end of things (thanks, WhyNot), are there any health benefits or deficits due to starting menses statistically late in life? Well, would you like the good news or the bad news? The good news is that youā€™re looking at a [lower risk of breast cancer](http://jnci.oxfordjournals.org/content/47/5/935.abstract)for every year menarche is delayed. The bad news is that[youā€™re more at risk for bone fractures\*](http://www.nature.com/bonekey/knowledgeenvironment/2007/0702/bonekey20060247/full/bonekey20060247.html), particularly as a little old lady. So lots of calcium (dairy, but also dark leafy greens, collards, blackstrap molasses, beans and almonds) and weight bearing exercise for you, to keep those bones nice and strong. Might be a good idea to ask your doctor about magnesium and Vitamin D, as well - she can run some tests and see if youā€™ve got any deficiencies that might affect your bone health down the line. \*Sorry, I canā€™t find ANY citations that arenā€™t to ridiculously abstruse studies inaccessible to the layperson. But yeah, itā€™s one of the risk factors they taught us in school. ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 26, 2012, 12:56am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/14 "2012-06-26T00:56:17Z")
I did not know that association with decreased peak bone mass. Interesting. ---
**Author:** ![Lasciel](https://avatars.discourse-cdn.com/v4/letter/l/e79b87/32.png) [@Lasciel](https://boards.straightdope.com/u/Lasciel)\ **Post date:** [June 26, 2012, 1:02am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/15 "2012-06-26T01:02:46Z")
> [@DSeid](#): > > Several potentially. > 2) Longer to grow. The growth spurt hits from a higher starting point. This one has me confused. Do you mean that it takes longer to reach full growth as an adult, or that the size of ā€œfull growthā€ as an adult is increased, or something else entirely? > [@WhyNot](#): > > The bad news is that[youā€™re more at risk for bone fractures\*](http://www.nature.com/bonekey/knowledgeenvironment/2007/0702/bonekey20060247/full/bonekey20060247.html), particularly as a little old lady. So lots of calcium (dairy, but also dark leafy greens, collards, blackstrap molasses, beans and almonds) and weight bearing exercise for you, to keep those bones nice and strong. Might be a good idea to ask your doctor about magnesium and Vitamin D, as well - she can run some tests and see if youā€™ve got any deficiencies that might affect your bone health down the line. I think I can handle that. I eat about a half-cup of almonds every day anyway, so that works out, I loooooove dairy, and my husband seems to think that I look better with shoulder muscles, so I do a lot of weightlifting. šŸ˜ƒ Interesting about the decrease in bone mass leading to fractures. Will that also make me ā€˜shrinkā€™ as I get older? ---
**Author:** ![DSeid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dseid/32/20194_2.png) [@DSeid](https://boards.straightdope.com/u/DSeid)\ **Post date:** [June 26, 2012, 1:42am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/16 "2012-06-26T01:42:17Z")
Itā€™s more of a delay, but from the perspective of a short child, or a parent concerned about their childā€™s being vertically challenged, it is important to be aware that the longer it takes for puberty to hit the taller they end up being, because they will be growing longer. The pattern is more easily recognized comparing boy early and late bloomers. We all knew the kid who was shaving in eight grade, the big tough guy kid. He didnā€™t grow any after that. By the end of High School he was the short guy who still acted tough but was sort of comedic thinking he was all that. We also all know the boy who was very short and prepubertal going into High School as the other boys were all in the midst of the growth spurt and he was growing but no where near as quickly. Then they all pretty much stopped growing just as he hit his growth spurt, which he continued maybe into Freshman year of college, going from the shorter kid to one of the taller young adults. For girls the growth spurt is early enough in puberty, and height less of a major issue most of the time, that the height is not noticed so much as the lack of breast development and or menarche. ---
**Author:** ![Tom\_Tildrum](https://avatars.discourse-cdn.com/v4/letter/t/e95f7d/32.png) [@Tom\_Tildrum](https://boards.straightdope.com/u/Tom_Tildrum)\ **Post date:** [June 26, 2012, 2:50am UTC](https://boards.straightdope.com/t/onset-of-menses-average-age/626233/17 "2012-06-26T02:50:27Z")
ā€œOnset of Mensesā€ sounds like a Henry Miller novel.