View source for Menarche

{{Short description|Female human's first menstrual cycle}}
{{distinguish|Minarchy}}
{{multiple issues|{{more medical citations needed|reason= overreliance on primary sources, and a good deal of uncited text|date=March 2021}}{{update|reason= many sources are dated, see [[WP:MEDDATE]]|date=March 2021}}}}
{{Human growth and development|state=autocollaps}}

'''Menarche''' ({{IPAc-en|m|ə|ˈ|n|ɑr|k|i}} {{respell|mə|NAR|kee}}; {{etymology|grc|''μήν'' (mēn)|month||''ἀρχή'' (arkhē)|beginning}}) is the first [[menstrual cycle]], or first [[menstruation|menstrual bleeding]], in female humans. From both social and medical perspectives, it is often considered the central event of female [[puberty]], as it signals the possibility of [[fertility]]. Girls experience menarche at different ages, but the most common age is 12.<ref>{{cite journal | pmid=11446429 | year=2001 | last1=Thomas | first1=F. | last2=Renaud | first2=F. | last3=Benefice | first3=E. | last4=De Meeüs | first4=T. | last5=Guegan | first5=J. F. | title=International variability of ages at menarche and menopause: Patterns and main determinants | journal=Human Biology | volume=73 | issue=2 | pages=271–290 | doi=10.1353/hub.2001.0029 | s2cid=12330919 | url=https://hal.umontpellier.fr/hal-02505288 }}</ref><ref>{{Cite book |url=https://link.springer.com/book/10.1007/978-1-4899-8026-7 |doi=10.1007/978-1-4899-8026-7 |title=International Handbook of Adolescent Pregnancy |year=2014 |isbn=978-1-4899-8025-0 |editor-last1=Cherry |editor-last2=Dillon |editor-first1=Andrew L. |editor-first2=Mary E. }} The statistics are dispersed throughout the chapters specific to different countries around the globe, summarized and cited in several scientific papers.</ref> Having menarche occur between the ages of 9–14 in the West is considered normal.<ref name="bmc">[https://www.cdc.gov/nchs/data/nhsr/nhsr146-508.pdf US National Health Statistics Report], September 2020</ref> 

The timing of menarche is influenced by female biology, as well as [[Genetics|genetic]], [[environmental factor]]s, and nutritional factors.<ref>{{Cite journal | vauthors = Karapanou O, Papadimitriou A |date=2010-09-30 |title=Determinants of menarche |journal=Reproductive Biology and Endocrinology |language=en |volume=8 |issue=1 |page=115 |doi=10.1186/1477-7827-8-115 |issn=1477-7827 |pmc=2958977 |pmid=20920296 |doi-access=free }}</ref> The mean age of menarche has declined over the last century, but the magnitude of the decline and the factors responsible remain subjects of contention. The worldwide average age of menarche is very difficult to estimate accurately, and it varies significantly by geographical region, race, ethnicity and other characteristics, and occurs mostly during a span of ages from 8 to 16, with a small percentage of girls having menarche by age 10, and the vast majority having it by the time they were 14.<ref name="bmc" />
There is a later age of onset in Asian populations compared to the West, but it too is changing with time. For example a Korean study in 2011 showed an overall average age of 12.7, with around 20% before age 12, and more than 90% by age 14.<ref>{{cite journal | doi=10.1186/s12978-016-0240-y | title=Age at menarche in Korean adolescents: Trends and influencing factors | year=2016 | last1=Lee | first1=Mee-Hwa | last2=Kim | first2=Shin Hye | last3=Oh | first3=Minkyung | last4=Lee | first4=Kuk-Wha | last5=Park | first5=Mi-Jung | journal=Reproductive Health | volume=13 | issue=1 | page=121 | pmid=27662834 | pmc=5035449 | doi-access=free }}</ref> A Chinese study from 2014 published in ''[[Acta Paediatrica]]'' showed similar results (overall average of age 12.8 in 2005 down to age 12.3 in 2014) and a similar trend in time, but also similar findings about ethnic, cultural, and environmental effects.<ref>{{cite journal | url=https://onlinelibrary.wiley.com/doi/abs/10.1111/apa.15441 | doi=10.1111/apa.15441 | title=The mean age of menarche among Chinese schoolgirls declined by 6 months from 2005 to 2014 | year=2021 | last1=Lei | first1=Yuanting | last2=Luo | first2=Dongmei | last3=Yan | first3=Xiaojin | last4=Zhang | first4=Jingshu | last5=Hu | first5=Peijin | last6=Ma | first6=Jun | last7=Song | first7=Yi | last8=Lau | first8=Patrick W. C. | journal=Acta Paediatrica | volume=110 | issue=2 | pages=549–555 | pmid=32573028 | s2cid=219988641 | url-access=subscription }}</ref> The average age of menarche was about 12.7 years in Canada in 2001,<ref>{{cite journal | vauthors = Al-Sahab B, Ardern CI, Hamadeh MJ, Tamim H | title = Age at menarche in Canada: results from the National Longitudinal Survey of Children & Youth | journal = BMC Public Health | volume = 10 | article-number = 736 | date = November 2010 | pmid = 21110899 | pmc = 3001737 | doi = 10.1186/1471-2458-10-736 | doi-access = free }}</ref> and 12.9 in the United Kingdom.<ref>{{cite book |url=http://vstudentworld.yolasite.com/resources/final_yr/gynae_obs/Hamilton%20Fairley%20Obstetrics%20and%20Gynaecology%20Lecture%20Notes%202%20Ed.pdf |page=29 |title=Obstetrics and Gynaecology |author=Hamilton-Fairley, Diana |edition=2nd |publisher=Blackwell |year=2004 |isbn=978-1-4051-2066-1 |access-date=2013-11-09 |archive-date=2018-10-09 |archive-url=https://web.archive.org/web/20181009065351/http://vstudentworld.yolasite.com/resources/final_yr/gynae_obs/Hamilton%20Fairley%20Obstetrics%20and%20Gynaecology%20Lecture%20Notes%202%20Ed.pdf }}</ref> A study of girls in Istanbul, Turkey, in 2011 found the median age at menarche to be 12.7 years.{{better source needed|date=March 2021}}<ref name="pmid21669888">{{cite journal | vauthors = Atay Z, Turan S, Guran T, Furman A, Bereket A | title = Puberty and influencing factors in schoolgirls living in Istanbul: end of the secular trend? | journal = Pediatrics | volume = 128 | issue = 1 | pages = e40–5 | date = July 2011 | pmid = 21669888 | doi = 10.1542/peds.2010-2267 | s2cid = 24970295 }}</ref> In the United States, an analysis of 10,590 women aged 15–44 taken from the 2013–2017 round of the CDC's National Survey of Family Growth
found a median age of 11.9 years (down from 12.1 in 1995), with a mean of 12.5 years (down from 12.6).<ref name="g613">{{cite journal | last=Martinez | first=Gladys M. | title=Trends and Patterns in Menarche in the United States: 1995 through 2013-2017 | journal=National Health Statistics Reports | issue=146 | date=2020 | issn=2332-8363 | pmid=33054923 | pages=1–12|url=https://www.cdc.gov/nchs/data/nhsr/nhsr146-508.pdf}}</ref>

==Physiology==
===Puberty===
Menarche is the culmination of a series of [[physiological]] and anatomic processes of [[puberty]]:
* Attainment of a sufficient [[body fat percentage]] (typically around 17% of total body mass).<ref name=hr>{{cite journal | vauthors = Frisch RE | title = Body fat, menarche, fitness and fertility | journal = Human Reproduction | volume = 2 | issue = 6 | pages = 521–33 | date = August 1987 | pmid = 3117838 | doi = 10.1093/oxfordjournals.humrep.a136582 }}</ref>
* Disinhibition of the [[GnRH]] pulse generator in the [[arcuate nucleus]] of the [[hypothalamus]].<ref name="StatPearls">{{cite book | vauthors = Lacroix AE, Gondal H, Langaker MD | chapter = Physiology, Menarche| chapter-url=https://www.ncbi.nlm.nih.gov/books/NBK470216/| title = StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|date=11 March 2023 |pmid=29261991|access-date=11 February 2025}}</ref>
* Secretion of [[estrogen]] by the [[ovary|ovaries]] in response to [[pituitary]] [[hormone]]s.
* Over an interval of about 2 to 3 years, estrogen stimulates growth of the [[uterus]] and breasts, as well as an increase in height, widening of the pelvis, and increased regional [[adipose tissue]].
* Estrogen stimulates growth and vascularity of the [[endometrium]], the lining of the uterus.
* Fluctuations of hormone levels can result in changes of adequacy of blood supply to parts of the endometrium.
* Death of some of the endometrial tissue from these hormone or blood supply fluctuations leads to ''deciduation'', a sloughing off of part of the lining with some blood, which together flows from the [[vagina]], i.e. menstrual flow.

Menarche tends to be painless and occurs without warning.<ref name="StatPearls" />

The ''menstruum'', or ''flow'', consists of a combination of fresh and clotted blood with endometrial tissue. Flow may be scanty in amount and might be as little as a single instance of "spotting". Like other [[menstruation|menses]], menarche may be accompanied by lower abdominal cramps.<ref name="StatPearls" />

===Relation to fertility===
For most girls, menarche does not mean that [[ovulation]] has occurred. In post-menarchal girls, about 80% of the cycles are [[anovulatory]] in the first year after menarche, 50% in the third, and 10% in the sixth year.<ref name="Apter D 1980 107–20">{{cite journal | vauthors = Apter D | title = Serum steroids and pituitary hormones in female puberty: a partly longitudinal study | journal = Clinical Endocrinology | volume = 12 | issue = 2 | pages = 107–20 | date = February 1980 | pmid = 6249519 | doi = 10.1111/j.1365-2265.1980.tb02125.x | s2cid = 19913395 }}</ref> Regular ovulation is usually indicated by predictable and consistent intervals between menses, and predictable and consistent patterns of flow (e.g., heaviness or cramping). Continuing ovulation typically requires a [[body fat percentage]] of at least 22%.<ref name=hr/>

Not every girl follows the typical pattern. Some girls ovulate prior to their first [[menstruation]]. Although unlikely, it is possible for a girl who has engaged in sexual intercourse shortly before her menarche to [[Conception (biology)|conceive]] and become pregnant (delaying her menarche until after the end of her pregnancy, if she carries to full term).

Younger age of menarche is not correlated with a younger age of first sexual intercourse.<ref>{{cite journal | vauthors = Marino JL, Skinner SR, Doherty DA, Rosenthal SL, Cooper Robbins SC, Cannon J, Hickey M | title = Age at menarche and age at first sexual intercourse: a prospective cohort study | journal = Pediatrics | volume = 132 | issue = 6 | pages = 1028–36 | date = December 2013 | pmid = 24218473 | doi = 10.1542/peds.2012-3634 | hdl = 11343/219824 | s2cid = 1930969 | url = http://minerva-access.unimelb.edu.au/bitstream/11343/219824/4/AAM_and_sexual_debut_R2.pdf | hdl-access = free }}</ref>

===Onset===
When menarche occurs, it confirms that the girl has had a gradual [[estrogen]]-induced growth of the [[uterus]], especially the [[endometrium]], and that the "outflow tract" from the uterus, through the [[cervix]] to the [[vagina]], is open.

When experiencing menarche, the blood flow (colloquially described as having one's "period") can vary from a slow and spotty discharge to a consistent blood flow for 3–7 days. The color of the blood ranges from bright red to brown in color; this is normal. Periods may be light or heavy.<ref>{{Cite web |date=2021-01-27 |title=First period: Early signs, how long it lasts, and self-care tips |url=https://www.medicalnewstoday.com/articles/first-period |access-date=2022-03-21 |website=www.medicalnewstoday.com |language=en}}</ref>

In very rare instances, menarche may occur at an unusually early age, preceding [[thelarche]] and other signs of puberty. This is termed ''isolated premature menarche'', but other causes of [[vaginal bleeding]] must be investigated and excluded.<ref name=AMN>{{cite web |author1=R. Stanhope |author2=C. Traggiai |title=Isolated Menarche |work=Precocious Puberty (Complete, Partial) |url=http://www.health.am/gyneco/more/isolated-menarche/ |year=2006 |publisher=Armenian Health Network |access-date=2006-11-26}}</ref>

When menarche has failed to occur for more than three years after thelarche, or beyond 15 years of age, the delay is referred to as [[primary amenorrhea]].

===Timing===
====Chronic illness====
Certain systemic or chronic illness can delay menarche, such as [[diabetes mellitus type 1]], [[cystic fibrosis]], asthma, [[inflammation|inflammatory diseases]],<ref name=UmlawskaKrzyzanowska2009>{{cite journal | vauthors = Umławska W, Krzyzanowska M | title = [Puberty in certain chronic illness] | journal = Pediatric Endocrinology, Diabetes, and Metabolism | volume = 15 | issue = 3 | pages = 216–18 | date = 2009 | pmid = 20384185 | type = Review }}</ref> and untreated [[celiac disease]],<ref name=LefflerGreen2015>{{cite journal | vauthors = Leffler DA, Green PH, Fasano A | title = Extraintestinal manifestations of coeliac disease | journal = Nature Reviews. Gastroenterology & Hepatology | volume = 12 | issue = 10 | pages = 561–71 | date = October 2015 | pmid = 26260366 | doi = 10.1038/nrgastro.2015.131 | s2cid = 15561525 | type = Review }}</ref><ref name=TersigniCastellani>{{cite journal | vauthors = Tersigni C, Castellani R, de Waure C, Fattorossi A, De Spirito M, Gasbarrini A, Scambia G, Di Simone N | display-authors = 6 | title = Celiac disease and reproductive disorders: meta-analysis of epidemiologic associations and potential pathogenic mechanisms | journal = Human Reproduction Update | volume = 20 | issue = 4 | pages = 582–93 | date = 2014 | pmid = 24619876 | doi = 10.1093/humupd/dmu007 | type = Review | doi-access = free | hdl = 10807/56796 | hdl-access = free }}</ref> among others.<ref name=TraggiaiStanhope2003>{{cite journal | vauthors = Traggiai C, Stanhope R | title = Disorders of pubertal development | journal = Best Practice & Research. Clinical Obstetrics & Gynaecology | volume = 17 | issue = 1 | pages = 41–56 | date = February 2003 | pmid = 12758225 | doi = 10.1053/ybeog.2003.0360 | type = Review }}</ref>  Sometimes, lab tests do not return determinative results, so that underlying pathologies are not identified and the girl is diagnosed with [[constitutional growth delay]].<ref name=WeiCrowne2015>{{cite journal | vauthors = Wei C, Crowne EC | title = Recent advances in the understanding and management of delayed puberty | journal = Archives of Disease in Childhood | volume = 101 | issue = 5 | pages = 481–88 | date = May 2016 | pmid = 26353794 | doi = 10.1136/archdischild-2014-307963 | s2cid = 5372175 | type = Review }}</ref>

====Conditions and disease states====
Studies have been conducted to observe the association of the timing of menarche with various conditions and diseases. Some studies have shown that there may be an association between early or late-age menarche and [[cardiovascular disease]], although the mechanism of the association is not well understood.<ref>{{cite journal | vauthors = Luijken J, van der Schouw YT, Mensink D, Onland-Moret NC | title = Association between age at menarche and cardiovascular disease: A systematic review on risk and potential mechanisms | journal = Maturitas | volume = 104 | pages = 96–116 | date = October 2017 | pmid = 28923182 | doi = 10.1016/j.maturitas.2017.07.009 }}</ref> A systematic review has concluded that early onset of menarche is a risk factor for [[insulin resistance]]<ref>{{cite journal | vauthors = Zhang Z, Hu X, Yang C, Chen X | title = Early age at menarche is associated with insulin resistance: a systemic review and meta-analysis | journal = Postgraduate Medicine | volume = 131 | issue = 2 | pages = 144–50 | date = March 2019 | pmid = 30560708 | doi = 10.1080/00325481.2019.1559429 | s2cid = 56178701 }}</ref> and [[breast cancer]] risk.<ref>{{cite journal | vauthors = Kapil U, Bhadoria AS, Sareen N, Singh P, Dwivedi SN | title = Reproductive factors and risk of breast cancer: A Review | journal = Indian Journal of Cancer | volume = 51 | issue = 4 | pages = 571–76 | date = 2014 | pmid = 26842199 | doi = 10.4103/0019-509X.175345 | doi-access = free }}</ref>

There is conflicting evidence regarding the association between obesity and timing of menarche; a meta-analysis and systematic review has determined that more studies must be conducted to make any definitive conclusions about this association.<ref>{{cite journal | vauthors = Li W, Liu Q, Deng X, Chen Y, Liu S, Story M | title = Association between Obesity and Puberty Timing: A Systematic Review and Meta-Analysis | journal = International Journal of Environmental Research and Public Health | volume = 14 | issue = 10 | page = 1266 | date = October 2017 | pmid = 29064384 | pmc = 5664767 | doi = 10.3390/ijerph14101266 | doi-access = free }}</ref>

====Effects of stress and social environment====
Some of the aspects of family structure and function reported to be independently associated with earlier menarche [antenatal and early childhood]
* Being non-white (in the UK)<ref name="D.H. Morris, M.E. Jones 2010">{{cite journal | vauthors = Morris DH, Jones ME, Schoemaker MJ, Ashworth A, Swerdlow AJ | title = Determinants of age at menarche in the UK: analyses from the Breakthrough Generations Study | journal = British Journal of Cancer | volume = 103 | issue = 11 | pages = 1760–64 | date = November 2010 | pmid = 21045834 | pmc = 2994234 | doi = 10.1038/sj.bjc.6605978 }}</ref>
* Having experienced [[pre-eclampsia]] in the womb<ref name="D.H. Morris, M.E. Jones 2010"/>
* Being a singleton, i.e. not a twin or triplet<ref name="D.H. Morris, M.E. Jones 2010"/>
* Low birthweight<ref name="D.H. Morris, M.E. Jones 2010"/>
* Not having been breast-fed<ref name="D.H. Morris, M.E. Jones 2010"/>
* Exposure to smoking<ref name="D.H. Morris, M.E. Jones 2010"/>
* High-conflict family relationships<ref>{{cite journal | vauthors = Belsky J, Steinberg L, Houts RM, Halpern-Felsher BL | title = The development of reproductive strategy in females: early maternal harshness --> earlier menarche --> increased sexual risk taking | journal = Developmental Psychology | volume = 46 | issue = 1 | pages = 120–28 | date = January 2010 | pmid = 20053011 | doi = 10.1037/a0015549 }}</ref>
* Lack of exercise in childhood<ref name="D.H. Morris, M.E. Jones 2010"/>

Other research has focused on the effect of childhood stress on timing of puberty, especially female. Stress is a vague term and studies have examined conditions ranging from family tensions or conflict to wartime refugee status with threat to physical survival. The more dire social conditions have been found to be associated with delay of maturation, an effect that is compounded by inadequate diet and nutrition. There is mixed evidence if milder degrees of stress can accelerate puberty in girls as would be predicted by [[life history theory]] and demonstrated in non-human mammals.<ref>{{cite journal | vauthors = Mishra GD, Cooper R, Tom SE, Kuh D | title = Early life circumstances and their impact on menarche and menopause | journal = Women's Health | volume = 5 | issue = 2 | pages = 175–190 | date = March 2009 | pmid = 19245355 | pmc = 3287288 | doi = 10.2217/17455057.5.2.175 }}</ref>

The understanding of these environmental effects is incomplete and the following cautions are relevant:
* Most of these "effects" are statistical associations revealed by [[epidemiology|epidemiologic]] surveys. Statistical associations are not necessarily causal, and secondary variables and alternative explanations can be possible instead. Effects of small size studies can never be confirmed or refuted for any individual child.
* Despite the small magnitude of effect, interpretations of the studies are politically controversial because this type of research is often be used for political advocacy. Accusations of bias based on political agenda sometimes accompany scientific criticism.
* [[Correlation does not imply causation]]. While correlation can be objectively measured, causation is statistically inferred. For example, some suggest that childhood stress is caused by precocious puberty recognized later, rather than being the cause of it.<ref>[[The Australian]], 3 April 2013. [http://www.theaustralian.com.au/news/health-science/early-onset-puberty-causes-emotional-issues-at-preschool-age/story-e6frg8y6-1226611493370 Early onset puberty causes emotional issues at preschool age] {{webarchive |url=https://web.archive.org/web/20130416032021/http://www.theaustralian.com.au/news/health-science/early-onset-puberty-causes-emotional-issues-at-preschool-age/story-e6frg8y6-1226611493370 |date=April 16, 2013 }}</ref>

====Changes in time of average age====
[[File:Acceleration1.jpg|thumb|upright=1.8|Secular trend in decrease in age of menarche in Western European and North American girls; Boaz (1999)<ref>Boaz, N.T. (1999). ''Essentials of biological anthropology.'' Prentice Hall, New Jersey, {{ISBN|0-13-080793-1}}.</ref>]]

There were few systematic studies of timing of menarche before the second half of the 20th century. Most older estimates of average onset of menarche were based on observation of a small, homogeneous, non-representative sample of the larger population, or based on recall by adult women, which is susceptible to error. Most sources agree that the average age of menarche in girls in modern societies has declined, though the reasons and the degree remain subjects of study. 

From the sixth to the 15th centuries in Europe, most women reached menarche at about 14, between the ages of 12 and 15.<ref>{{cite journal |author1=Amundsen Darrel |author2=Dreis Carol Jean | year = 1973 | title = The Age of Menarche in Medieval Europe | journal = Human Biology | volume = 45 | issue = 3| pages = 363–68 |pmid=4584336 }}</ref> The average age of menarche dropped from 14–15 years in the early 20th century to 12–13 years in the present, but girls in the 19th century had a later age of menarche (16 to 18 years) compared to girls in earlier centuries.<ref>{{cite journal |title=Average age of Menarche in History |journal=British Medical Journal |date=2001 |pmid=11337438 |url=https://www.bmj.com/content/322/7294/1095.full |last1=Whincup |first1=P. H. |last2=Gilg |first2=J. A. |last3=Odoki |first3=K. |last4=Taylor |first4=S. J. |last5=Cook |first5=D. G. |volume=322 |issue=7294 |pages=1095–1096 |doi=10.1136/bmj.322.7294.1095 |pmc=31261 }}</ref> A large North American survey reported a 2–3 month decline from the mid-1970s to the mid-1990s.<ref name=AndersonEtAl2003>{{cite journal |vauthors = Anderson SE, Dallal GE, Must A |title = Relative weight and race influence average age at menarche: results from two nationally representative surveys of US girls studied 25 years apart |journal = Pediatrics | volume = 111 |issue = 4 Pt 1 | pages = 844–50 | date = April 2003 | pmid = 12671122 | doi = 10.1542/peds.111.4.844 }}</ref> A 2011 study found that each 1&nbsp;kg/m<sup>2</sup> increase in childhood [[body-mass index]] (BMI) can be expected to result in a 6.5% higher absolute risk of early menarche (before age 12 years).<ref>{{cite journal | vauthors = Mumby HS, Elks CE, Li S, Sharp SJ, Khaw KT, Luben RN, Wareham NJ, Loos RJ, Ong KK | display-authors = 6 | title = Mendelian Randomisation Study of Childhood BMI and Early Menarche | journal = Journal of Obesity | volume = 2011 | article-number = 180729 | year = 2011 | pmid = 21773002 | pmc = 3136158 | doi = 10.1155/2011/180729 | doi-access = free }}</ref> This is called the '''secular trend'''.<ref name="Strickland2001">{{cite book|editor-first1=Bonnie B.|editor-last1=Strickland|title=The Gale Encyclopedia of Psychology|url=https://books.google.com/books?id=kSoZAQAAIAAJ&pg=PA528 |year=2001 |chapter=Puberty |chapter-url=<!-- not a Google Books -->|publisher=Gale Group|isbn=978-0-7876-4786-5|page=528 |edition=Second |quote=The sequence and age range of the developmental changes associated with puberty can vary widely. Although most children begin puberty between the ages of 10 and 12, it can start at any age from 8 to 16. The most obvious determining factor is gender; on average, puberty arrives earlier for girls than boys. Heredity also appears to play an important role. Compared to an overall age range of nine to 18 for menarche, the age difference for sisters averages only 13 months and for identical twins, less than three months. Body weight is a factor as well: puberty often begins earlier in heavier children of both sexes and later in thinner ones. The onset of menstruation, in particular, appears to be related to amounts of body fat. Girls with little body fat, especially athletes, often start menstruating at a later than-average age. Over the past 100 years, puberty has tended to begin increasingly early in both sexes (a phenomenon called the ''secular trend'').}}</ref><ref>{{cite book |first=Laurence |last=Steinberg|editor-first1=Bonnie B.|editor-last1=Strickland  |title=The Gale Encyclopedia of Psychology |year=2000 |chapter=Adolescence |chapter-url=|publisher=Gale Group|isbn=0-7876-4786-1 |page=11 |edition=Second |quote=The timing of physical maturation varies widely. In the United States today, menarche, the first menstrual period, typically occurs around age 12, although some youngsters start puberty when they are only eight or nine, others when they are well into their teens. The duration of puberty also varies greatly: eighteen months to six years in girls and two to five years in boys.}}</ref>

In 2002, fewer than 10% of US girls started to menstruate before 11 years of age, and 90% of all US girls were menstruating by 13.75 years of age, with a median age of 12.43 years. This age at menarche is not much different (0.3 years earlier) than that reported for US girls in 1973. Age at menarche for non-Hispanic black girls was significantly earlier than that of white girls, whereas non-white Mexican-American girls were only slightly earlier than white girls.<ref name=Chumlea>{{cite journal | vauthors = Chumlea WC, Schubert CM, Roche AF, Kulin HE, Lee PA, Himes JH, Sun SS |title = Age at menarche and racial comparisons in US girls | journal = Pediatrics | volume = 111 | issue = 1 | pages = 110–13 | date = January 2003 | pmid = 12509562 | doi = 10.1542/peds.111.1.110 }}</ref>

== Society and culture ==
{{Main|Culture and menstruation}}
{{See also|Seclusion of girls at puberty}}

Menstruation is a cultural as well as scientific phenomenon as many societies have rituals, social norms, and religious laws associated with it. These typically begin at menarche and may be enacted during each menstruation cycle. The menarches are important in determining a status change for the girls. Upon menarche and completion of the ritual, they have become a woman as defined by their culture.

Canadian psychological researcher Niva Piran claims that menarche or the perceived average age of puberty is used in many cultures to separate girls from activity with boys, and to begin transition into womanhood.<ref>{{cite book |last1=Bobel |first1=C. |title=The Palgrave Handbook of Critical Menstruation Studies |last2=Winkler |first2=I. T. |last3=Fahs |first3=B. |last4=Hasson |first4=K. A. |last5=Kissling |first5=E. A. |last6=Roberts |first6=T. A. |last7=Piran |first7=N. |year=2020 |isbn=978-981-15-0613-0 |pages=201–214 |chapter=The Menarche Journey: Embodied Connections and Disconnections |doi=10.1007/978-981-15-0614-7_18 |pmid=33347201 |chapter-url=https://pubmed.ncbi.nlm.nih.gov/33347201/ |s2cid=226484326}}</ref> For example, post-menarche, young women compete in field hockey while young men play ice hockey.

=== Celebratory ceremonies ===
[[File:140111_Azuki_Museum_Himeji_Hyogo_pref_Japan11bs.jpg|thumb|upright|[[Sekihan]], a traditional Japanese dish of sticky rice steamed with azuki beans, was sometimes served after menarche.]]

Some cultures have observed rites of passage such as a party or other celebration, for a girl experiencing menarche, in the past and the present.<ref>Hartman, Holly. ''Girlwonder: Every Girl's Guide to the Fantastic Feats, Cool Qualities, and Remarkable Abilities of Women and Girls.'' Boston: Houghton Mifflin, 2003.</ref>

==== Past ====
In ancient Japan, when a Japanese girl had her first period, the family sometimes celebrated by eating red-colored rice and beans (''[[sekihan]]''). Although both blood and sekihan rice are red, this was not of symbolic significance. All rice in ancient Japan was red; it was also rare and precious. (At most other times, [[millet]] was eaten instead.) The celebration was kept a secret from extended family until the rice was served.<ref name="Girls almanac">{{cite book |vauthors=Siegel A |title=Information Please Girls' Almanac |year=1995 |publisher=Houghton Mifflin Harcourt |isbn=978-0-395-69458-9 |url=https://books.google.com/books?id=jjdI-5tfGOIC&q=Ulithi+tribe+kufar&pg=PA13 |access-date=2013-11-09}}</ref>

==== Present ====
In [[Hinduism in South India|South Indian Hindu]] communities, young women are given a special menarche ceremony called [[Ruthu Sadangu]]; at that time, they begin to wear two-piece [[saris]].<ref>{{cite book |vauthors = Chockalingam K |title=Census of India, 1971: A. General report |year=1973 |url=https://books.google.com/books?id=OMsXAAAAMAAJ&q=Ruthu+Sadangu+menarche+india |access-date=2013-11-09}}</ref>

In Morocco, the girl is thrown a celebration. All of her family members are invited and the girl is showered with money and gifts. [[Quinceañera]] in Latin America, is similar, except that the specific age of 15 marks the transition rather than menarche.

The [[Mescalero]] Apaches place high importance on their menarche ceremony and it is regarded as the most important ritual in their tribe. Each year, there is an eight-day event celebrating all of the girls who have menstruated in the past year. The days are split between feasting and private ceremonies reflecting on their new womanly status.<ref>{{cite book |vauthors=Crawford O'Brien SJ |title=American Indian religious traditions: an Encyclopedia, Volume 2 |year=2005 |publisher=ABC-CLIO |url=https://books.google.com/books?id=SEopBoB8ch0C&pg=PA279 |isbn=978-1-57607-517-3 |access-date=2013-11-09}}</ref>

In the United States, public schools have a [[sex education]] program that teaches girls about menstruation and what to expect at the onset of menarche; this takes place between the fifth and eight grades. Like most of the modern industrialized world, menstruation is a private matter and a girl's menarche is not a community phenomenon.<ref>{{cite book | vauthors = Freidenfelds L |title=The Modern Period: Menstruation in Twentieth Century America |year=2009 |publisher=JHU Press |isbn=978-0-8018-9245-5 |url=https://books.google.com/books?id=n58U9B9BqhQC |access-date=2013-11-09}}</ref>

=== Rituals of purification ===
The [[Ulithi]] tribe of [[Micronesia]] call a girl's menarche ''kufar''. She goes to a [[menstrual house]], where the women bathe her and recite spells. She will have to return to the menstruation hut every time she menstruates. Her parents build her a private hut that she will live in until she is married.<ref name="Girls almanac" />

In Sri Lanka, an astrologer is contacted to study the alignment of stars when the girl experiences menarche because it is believed that her future can be predicted. The women of the family then gather in her home and scrub her in a [[ritual bathing]] ceremony. Her family then throws a familial party at which the girl wears white and may receive gifts.<ref name="Girls almanac" />

In Ethiopia, [[Ethiopian Jewish|Beta Israel Jewish]] women were separated from male society and sent to menstruation huts during menarche and every menstruation following as the blood associated with menstruation in the Beta Israel Jewish culture was [[ritual purity|believed to be impure]]. The Beta Israel Jews built their villages surrounding and near bodies of water specifically for their women to have a place to clean themselves. The menstruation huts were built close to these bodies of water.<ref>{{cite book|vauthors = Tal I |title=Exploring the Meaning of Becoming a Woman in Non-Western Culture: A narrative Analysis of First Menstruation Stories of Ethiopian Jewish Women|year=2004|page=64}}</ref>

In India, [[purdah]] is practiced by some Hindu and Muslim communities. Women, starting at menarche and continuing with each subsequent period, are separated from men, and also wear different garments to conceal their skin during menstruation. 

In Australia, the [[Indigenous Australians|Aboriginals]]{{which|date=June 2014}} treat a girl to "love magic". She is taught the ways of womanhood by the other women in her tribe. Her mother builds her a [[menstruation hut]] to which she confines herself for the remainder of her menses. The hut is burned and she is bathed in the river at the end of menstruation. When she returns to the village,{{clarify|date=June 2014}} she is paired with a man who will be her husband.<ref name="Girls almanac" />

In Nigeria, the [[Tiv people|Tiv]] ethnic group [[scarification|cut four lines]] into the abdomen of their girls during menarche. The lines are supposed to represent fertility.<ref name="Girls almanac" />

=== Rituals of strength ===
The [[Navajo people|Navajo]] have a celebration called [[Blessing Way|''kinaalda'']]. Girls are expected to demonstrate their strength through footraces. The girls make a cornmeal pudding for the tribe to taste. Girls who undergo menarche wear special clothes and style their hair like the Navajo goddess [[Asdzą́ą́ Nádleehé|Changing Woman]].<ref name="Girls almanac" />

The [[Nuu-chah-nulth people|Nuu-chah-nulth]] (also known as the Nootka) believe that physical endurance is the most important quality in young women. At menarche the girl is taken out to sea and left there to swim back.<ref name="Girls almanac" />

== Movies, TV, and novels ==
Girls experiencing their first periods are part of many movies, particularly ones that include [[Coming of age|coming-of-age]] plot lines, such as ''[[The Blue Lagoon (1980 film)|The Blue Lagoon]]'' (1980), ''[[The Company of Wolves]]'' (1984), ''[[An Angel at My Table]]'' (1990), ''[[Only Yesterday (1991 film)|Only Yesterday]]'' (1991), ''[[My Girl (film)|My Girl]]'' (1991), ''[[Return to the Blue Lagoon]]'' (1991), ''[[Eve's Bayou|Eve's Bayou]]'' (1997), and ''[[A Walk on the Moon]]'' (1999). 

Menarche is also discussed in an episode of the [[Disney Channel]] animated series ''[[Baymax!]]'' (2022) in which the eponymous healthcare robot helps a girl deal with her first period.

In a 2022 episode of ''[[The Ghost and Molly McGee]]'' called "A Period Piece", Molly's friend Libby experiences her first period during a sleepover. Molly, not having experienced menarche yet, feels insecure about her maturity and tries to prove her friends that she can be as mature as them.

A third Disney Channel cartoon, ''[[Moon Girl and Devil Dinosaur]]'', touched on the subject in the 2025 episode "Full Moon", in which the titular superhero experiences her first period, which helps fix her strained relationship with her mother.

In the horror movie ''[[Carrie (1976 film)|Carrie]]'' (1976), an adaptation of the [[Stephen King]] [[Carrie (novel)|novel of the same name]], protagonist [[Carrie White]] experiences menarche as she showers after the school gym class. Unaware of what is happening to her, she panics and pleads for help, but the other girls respond by bullying her. Menarche unleashes Carrie's telekinetic powers which are key to her wild transformation that causes death and destruction.<ref>{{Cite web |last=Charisma |first=Tina |date=April 1, 2021 |title=A Brief History of Onscreen Periods |url=https://www.vulture.com/article/periods-in-movies-and-tv.html |url-status=live |archive-url=https://web.archive.org/web/20210401145350/https://www.vulture.com/article/periods-in-movies-and-tv.html |archive-date=April 1, 2021 |access-date=August 31, 2022 |website=[[Vulture (website)|Vulture]]}}</ref>  This theme is common to horror movies, another example being the Canadian horror movie ''[[Ginger Snaps (film)|Ginger Snaps]]'' (2000), where the protagonist's first period is central to her gradual transformation into a [[werewolf]]. The theme of transformation around menarche is similarly present in ''[[Turning Red]]'' (2022), although the film also explores other aspects of puberty and the protagonist does not yet have her first period.

One of the better-known middle reader (8 to 12 year old) novels in the US and Canada about the year leading up to menarche in the 1970s to 1990s is ''[[Are You There God? It's Me, Margaret]]'' (1970) by [[Judy Blume]].

==See also==
* [[Puberty]]
* [[Gonadarche]]
* [[Thelarche]]
* [[Menopause]], the equivalent opposite change at the end of the child-bearing years
* [[Delayed puberty]]

==References==
{{Reflist|30em}}

==Further reading==
{{refbegin}}
* {{cite journal | vauthors = Gluckman PD, Hanson MA | title = Evolution, development and timing of puberty | journal = [[Trends in Endocrinology and Metabolism]] | volume = 17 | issue = 1 | pages = 7–12 | date = January 2006 | pmid = 16311040 | doi = 10.1016/j.tem.2005.11.006 | s2cid = 26141301 }}
* {{cite journal | vauthors = Quinlan R |doi=10.1016/S1090-5138(03)00039-4 |url=http://public.wsu.edu/~rquinlan/Quinlan%20E&HB%2024(6).pdf |title=Father absence, parental care, and female reproductive development |year=2003 |journal=[[Evolution and Human Behavior]] |volume=24 |pages=376–90 |issue=6 |bibcode=2003EHumB..24..376Q |access-date=2022-02-21 |archive-date=2017-08-09 |archive-url=https://web.archive.org/web/20170809153517/https://public.wsu.edu/~rquinlan/Quinlan%20E%26HB%2024%286%29.pdf }}
* {{cite journal |last1=Papadimitriou |first1=Anastasios |title=The Evolution of the Age at Menarche from Prehistorical to Modern Times |journal=[[Journal of Pediatric and Adolescent Gynecology]] |date=2016 |volume=29 |issue=6 |pages=527–530 |doi=10.1016/j.jpag.2015.12.002|pmid=26703478 }}
{{refend}}

==External links==
* [http://www.livescience.com/4143-girl-period-depends-lives.html Discusses some of the social influences]

{{Menstrual cycle}}
{{Reproductive physiology}}
{{Authority control}}

[[Category:Developmental biology]]
[[Category:Developmental stages]]
[[Category:Menstrual cycle]]
[[Category:Pediatrics]]
[[Category:Puberty]]
[[Category:Sexuality and age]]
[[Category:Human female endocrine system]]

[[ja:月経#初潮]]