Editing Sexual intercourse (section)

===Reproduction===
{{Main|Sexual reproduction|Human reproduction}}
[[File:Pregnancy chance by day near ovulation.jpg|thumb|Chance of [[human fertilization|fertilization]] by [[menstrual cycle]] day relative to ovulation<ref name="DunsonBaird1999">{{cite journal|last1=Dunson|first1=D.B.|author1-link=David Dunson|last2=Baird|first2=D.D.|author2-link=Donna Baird|last3=Wilcox|first3=A.J.|last4=Weinberg|first4=C.R.|author4-link=Clarice Weinberg|title=Day-specific probabilities of clinical pregnancy based on two studies with imperfect measures of ovulation|journal=Human Reproduction|volume=14|issue=7|year=1999|pages=1835–1839|issn=1460-2350|doi=10.1093/humrep/14.7.1835|pmid=10402400|doi-access=free}}</ref>]]
[[File:Coition of a Hemisected Man and Woman.jpg|thumb|upright=0.8|right|"Coition of a Hemisected Man and Woman" (c. 1492), an interpretation of what happens inside the body during coitus, by [[Leonardo da Vinci]]]]
Natural human reproduction involves penile–vaginal penetration,<ref name="Evan Jones">{{cite book |title=Human Reproductive Biology |isbn =978-0-12-088465-0 |publisher=[[Academic Press]] |year=2006 |pages=[https://archive.org/details/humanreproductiv0000jone_l0u3/page/205 205-206] |access-date=June 5, 2022 <!-- Coitus (sexual intercourse) --> |url=https://archive.org/details/humanreproductiv0000jone_l0u3|url-access=registration|author1=Richard Evan Jones |author2=Kristin H. López }}</ref> during which [[semen]], containing male gametes known as [[Spermatozoon|sperm]] cells or spermatozoa, is [[ejaculated]] through the penis into the vagina. The sperm passes through the [[vaginal vault]], [[cervix]] and into the [[uterus]], and then into the [[fallopian tube]]s. Millions of sperm are ejaculated to increase the chances of [[Human fertilization|fertilization]] (see [[Human sperm competition|sperm competition]]), but only one is sufficient to fertilize an egg or [[ovum]]. When a fertile ovum from the female is present in the fallopian tubes, the male gamete fertilizes the ovum, forming a new [[embryo]]. [[Pregnancy]] begins after the fertilized ovum is implanted in the lining of the uterus (the [[endometrium]]).<ref name="Evan Jones"/><ref name="Starr3">{{cite book| author = Cecie Starr|author2= Beverly McMillan|title = Human Biology| publisher = [[Cengage Learning]] | year = 2015 | page = 339| access-date = December 27, 2017 |isbn = 978-1-305-44594-9| url =https://books.google.com/books?id=lS5-BAAAQBAJ&pg=PT339}}</ref>

[[Pregnancy rate#Pregnancy rate for sexual intercourse|Pregnancy rates for sexual intercourse]] are highest during the [[menstrual cycle]] time from some five days before until approximately one day after ovulation (this is sometimes called the [[fertile window]]).<ref name=":1">{{Cite journal |last1=Gibbons |first1=Tatjana |last2=Reavey |first2=Jane |last3=Georgiou |first3=Ektoras X |last4=Becker |first4=Christian M |date=September 15, 2023 |editor-last=Cochrane Gynaecology and Fertility Group |title=Timed intercourse for couples trying to conceive |journal=Cochrane Database of Systematic Reviews |language=en |volume=2023 |issue=9 |pages=CD011345 |doi=10.1002/14651858.CD011345.pub3|pmid=37709293 |pmc=10501857 }}</ref> For optimal pregnancy chance, there are recommendations of [[vaginal intercourse]] every one or two days,<ref>{{cite web|url=https://www.mayoclinic.org/healthy-lifestyle/getting-pregnant/in-depth/how-to-get-pregnant/art-20047611|title=How to get pregnant|website=[[Mayo Clinic]]|date=November 2, 2016|access-date=February 16, 2018}}</ref> or every two or three days.<ref>{{cite web|url=https://www.nice.org.uk/guidance/cg156/ifp/chapter/trying-for-a-baby|title=Fertility problems: assessment and treatment, Clinical guideline [CG156]|website=[[National Institute for Health and Care Excellence]]|date=February 20, 2013 |access-date=February 16, 2018}} Published date: February 2013. Last updated: September 2017</ref> Some people who are trying to conceive may choose to time vaginal intercourse with the fertile window, a practice that is sometimes called 'timed intercourse'.<ref name=":1" /> Timed intercourse using urine tests that predict ovulation may help improve the rate of pregnancy and live births for some couples trying to conceive such as those who have been trying for less than 12 months and who are under 40 years old; however, it is not clear from medical evidence if timed intercourse improves the rate of ultrasound-confirmed pregnancies and it is also not clear if timed intercourse has an effect on a person's level of stress or their quality of life.<ref name=":1" /> Studies have shown no significant difference between different [[sex positions]] and pregnancy rate, as long as it results in [[ejaculation]] into the vagina.<ref name=americanpregnancy>{{cite web|url=http://americanpregnancy.org/getting-pregnant-ebook/p7M7O0q1c71703C/gettingpregnant.pdf|title=The Essential Guide to Getting Pregnant|website=American Pregnancy Association|author=Philip B. Imler & David Wilbanks|date=November 2019|access-date=February 16, 2018|archive-date=June 1, 2018|archive-url=https://web.archive.org/web/20180601033115/http://americanpregnancy.org/getting-pregnant-ebook/p7M7O0q1c71703C/gettingpregnant.pdf|url-status=dead}}</ref>

When a [[sperm donor]] has sexual intercourse with a woman who is not his partner and for the sole purpose of impregnating the woman, this may be known as natural [[insemination]], as opposed to [[artificial insemination]]. Artificial insemination is a form of [[assisted reproductive technology]], which are methods used to achieve pregnancy by artificial or partially artificial means.<ref name="Bobick and Balaban">{{cite book|author1=James Bobick |author2=Naomi Balaban |title=The Handy Anatomy Answer Book|isbn=978-1-57859-328-6|publisher=[[Visible Ink Press]]|year=2008|pages=306–307|access-date=August 21, 2013|url=https://books.google.com/books?id=LBI2Sg2yYMoC&pg=PA305}}</ref> For artificial insemination, [[sperm donors]] may donate their sperm through a [[sperm bank]], and the insemination is performed with the express intention of attempting to impregnate the female; to this extent, its purpose is the medical equivalent of sexual intercourse.<ref name="Sharma">{{cite book|author=R.K. Sharma|title=Concise Textbook Of Forensic Medicine & Toxicology|isbn=978-81-312-1145-8|publisher=[[Elsevier|Elsevier India]]|year=2007|pages=113–116|access-date=October 13, 2013|url=https://books.google.com/books?id=_zAwlKX_zNwC&pg=PA113}}</ref><ref name="O'Toole">{{cite book|author=Mosby, Marie T. O'Toole|title=Mosby's Medical Dictionary|isbn=978-0-323-11258-1|publisher=[[Elsevier Health Sciences]]|year=2013|page=138|access-date=October 13, 2013|url=https://books.google.com/books?id=aW0zkZl0JgQC&pg=PA138}}</ref> [[Intracervical insemination|Intracervical insemination (ICI)]], which involves the deposit of (usually) raw semen in the vagina of a woman, is in effect a substitute for intercourse and is often contrasted with 'normal intercourse' in this context. Reproductive methods also extend to gay and lesbian couples. For gay male pairings, there is the option of [[Surrogacy|surrogate]] pregnancy; for lesbian couples, there is donor insemination in addition to choosing surrogate pregnancy.<ref name="Berkowitz">{{cite journal |vauthors=Berkowitz D, Marsiglio W | s2cid = 38458107 | year = 2007 | title = Gay Men: Negotiating Procreative, Father, and Family Identities | journal = Journal of Marriage and Family | volume = 69 | issue = 2| pages = 366–381 | doi = 10.1111/j.1741-3737.2007.00371.x }}</ref><ref name="Burda">{{Cite book| author = Joan M. Burda| title = Gay, lesbian, and transgender clients: a lawyer's guide | publisher = [[American Bar Association]]| year = 2008 |pages =69–74| isbn = 978-1-59031-944-4|access-date=July 28, 2011|url=https://books.google.com/books?id=QdzB1f8Y8Q8C&pg=PA69}}</ref> Some women use artificial insemination to become [[single mothers by choice]].<ref>{{cite journal |last1=Fiese |first1=Barbara |title=Single Mothers by Choice: Mother–Child Relationships and Children's Psychological Adjustment |journal=J Fam Psychol |date=2016 |volume=30 |issue=4 |pages=409–418 |doi=10.1037/fam0000188 |pmid=26866836 |pmc=4886836 }}</ref>