Editing Woman (section)

=== Hormonal characteristics, menstruation and menopause ===
{{Main|Menstrual cycle|Menstruation}}
[[Female puberty]] triggers bodily changes that enable [[sexual reproduction]] via [[human fertilization|fertilization]]. In response to chemical signals from the [[pituitary gland]], the [[ovaries]] secrete hormones that stimulate maturation of the body, including increased height and weight, body hair growth, breast development and [[menarche]] (the onset of menstruation).<ref name="UK menarche">{{cite book | last=Hamilton-Fairley | first=Diana | title=Lecture notes. Obstetrics and gynaecology | publisher=Wiley-Blackwell | publication-place=Chichester, UK | date=2009 | isbn=978-1-4051-7801-3 | oclc=230193908}}</ref>

[[File:Pregnancy 26 weeks 1.jpg|thumb|upright|A pregnant woman|alt=nude woman in the middle of pregnancy]]

Most girls go through [[menarche]] between ages 12–13,<ref name="Canadian menarche">{{cite journal|title=Age at menarche in Canada: results from the National Longitudinal Survey of Children & Youth |year= 2010 |pmid=21110899 |doi=10.1186/1471-2458-10-736 |pmc=3001737 |volume=10 |vauthors=Al-Sahab B, Ardern CI, Hamadeh MJ, Tamim H |journal=BMC Public Health |page=736 |doi-access= free }}</ref><ref name="U.S. menarche">{{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=844–850 |date=April 2003 |pmid=12671122 |doi=10.1542/peds.111.4.844}}</ref> and are then capable of becoming [[pregnant]] and [[childbirth|bearing children]]. Pregnancy generally requires [[Insemination|internal fertilization]] of the eggs with [[Spermatozoon|sperm]], via either [[sexual intercourse]] or [[artificial insemination]], though [[in vitro fertilization]] allows fertilization to occur outside the human body.<ref>{{cite web|date=November 14, 2014|title=What is Assisted Reproductive Technology? {{!}} Reproductive Health |url=https://www.cdc.gov/art/whatis.html|url-status=live|archive-url=https://web.archive.org/web/20171101183209/https://www.cdc.gov/art/whatis.html|archive-date=November 1, 2017|publisher=CDC}}</ref> Humans are similar to other large mammals in that they usually give birth to a single offspring per pregnancy, but are unusual in being [[Precociality and altriciality|altricial]] compared to most other large mammals, meaning young are [[Child development|undeveloped]] at time of birth and require the aid of their parents or guardians to fully mature.<ref>{{cite web |title=Overview of Multiple Pregnancy |url=https://www.stanfordchildrens.org/en/topic/default?id=overview-of-multiple-pregnancy-85-P08019 |website=Stanford Medicine Children’s Health }}</ref> Sometimes humans have [[multiple birth]]s, most commonly [[twin]]s.<ref>{{Cite web |title=Twins, Triplets, Multiple Births |url=https://medlineplus.gov/twinstripletsmultiplebirths.html |access-date=2022-07-25 |website=medlineplus.gov}}</ref>

Usually between ages 49–52, a woman reaches [[menopause]], the time when menstrual periods stop permanently, and they are no longer able to bear children.<ref name="NIH2013Def">{{cite web|date=2013-06-28|title=Menopause: Overview|url=http://www.nichd.nih.gov/health/topics/menopause/Pages/default.aspx|url-status=dead|archive-url=https://web.archive.org/web/20150402111845/http://www.nichd.nih.gov/health/topics/menopause/Pages/default.aspx|archive-date=2 April 2015|access-date=8 March 2015|publisher=Eunice Kennedy Shriver National Institute of Child Health and Human Development|df=dmy-all}}</ref><ref name="PubMed2013">{{cite web|date=29 August 2013|title=Menopause: Overview|url=https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072495/|url-status=live|archive-url=https://web.archive.org/web/20170910181404/https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0072495/|archive-date=10 September 2017|access-date=8 March 2015|publisher=PubMedHealth|df=dmy-all}}</ref><ref name="Tak2015">{{cite journal|vauthors=Takahashi TA, Johnson KM|date=May 2015|title=Menopause|journal=The Medical Clinics of North America|volume=99|issue=3|pages=521–34|doi=10.1016/j.mcna.2015.01.006|pmid=25841598|doi-access=free}}</ref> Unlike most other mammals, the human lifespan usually extends many years after menopause.<ref>{{Cite journal |last1=Hawkes |first1=K. |last2=O’Connell |first2=J. F. |last3=Jones |first3=N. G. Blurton |last4=Alvarez |first4=H. |last5=Charnov |first5=E. L. |date=1998-02-03 |title=Grandmothering, menopause, and the evolution of human life histories |journal=Proceedings of the National Academy of Sciences |volume=95 |issue=3 |pages=1336–1339 |doi=10.1073/pnas.95.3.1336 |pmc=18762 |pmid=9448332|bibcode=1998PNAS...95.1336H |doi-access=free }}</ref> Many women become [[Grandparent|grandmothers]] and contribute to the care of grandchildren and other family members.<ref>{{Cite web |title=Increasingly Indispensable Grandparents {{!}} YaleGlobal Online |url=https://archive-yaleglobal.yale.edu/content/increasingly-indispensable-grandparents |access-date=2022-07-28 |website=archive-yaleglobal.yale.edu |language=en}}</ref> Many biologists believe that the extended human lifespan is evolutionarily driven by [[kin selection]], though other theories have also been proposed.<ref>{{Cite journal |last1=Kaptijn |first1=Ralf |last2=Thomese |first2=Fleur |last3=van Tilburg |first3=Theo G. |last4=Liefbroer |first4=Aart C. |date=December 2010 |title=How Grandparents Matter: Support for the Cooperative Breeding Hypothesis in a Contemporary Dutch Population |journal=Human Nature |language=en |volume=21 |issue=4 |pages=393–405 |doi=10.1007/s12110-010-9098-9 |pmid=21212819 |pmc=2995872 }}</ref><ref>{{Cite journal |last=Peccei |first=Jocelyn Scott |title=Menopause: Adaptation or epiphenomenon? |journal=Evolutionary Anthropology: Issues, News, and Reviews |date=2001 |volume=10 |issue=2 |pages=43–57 |doi=10.1002/evan.1013 }}</ref><ref>{{Cite journal |last=Kyriazis |first=Marios |title=Ageing Throughout History: The Evolution of Human Lifespan |journal=Journal of Molecular Evolution |date=2020 |language=en |volume=88 |issue=1 |pages=57–65 |doi=10.1007/s00239-019-09896-2 |pmid=31197416 |bibcode=2020JMolE..88...57K }}</ref><ref>{{cite book |doi=10.1002/9781118924396.wbiea2162 |chapter=Grandmother Hypothesis, Grandmother Effect, and Residence Patterns |title=The International Encyclopedia of Anthropology |date=2018 |last1=Blell |first1=Mwenza |pages=1–5 |isbn=978-0-470-65722-5 }}</ref>