Editing Turner syndrome (section)

====Fertility====
Women with Turner syndrome are at extremely high risk for primary ovarian insufficiency (POI) and infertility. Although about 70–80% have no spontaneous pubertal development and 90% experience primary amenorrhea, the remainder may possess a small residual of ovarian follicles at birth or early childhood.<ref>{{cite journal | vauthors = ((Journal of Pediatric and Adolescent Gynecology)) | title = Fertility Preservation in Women with Turner Syndrome: A Comprehensive Review and Practical Guidelines | journal = Journal of Pediatric and Adolescent Gynecology | volume = 29 | issue = 5 | pages = 409–416 | date = October 2016 | doi = 10.1016/j.jpag.2015.10.011 | pmid = 26485320 | pmc = 5015771 }}</ref>

Early in gestation, fetuses with Turner syndrome have a normal number of [[gamete]]s in their developing ovaries, but this starts decreasing rapidly as early as 18 weeks of pregnancy; by birth, girls with the condition have markedly reduced follicular counts.<ref name="Finlayson Lia Reema Fertility Preservation for Turner Syndrome">{{cite book |doi=10.1007/978-3-030-34150-3_4 |chapter=Fertility Preservation for Turner Syndrome |title=Turner Syndrome |date=2020 |last1=Finlayson |first1=Courtney |last2=Bernardi |first2=Lia |last3=Habiby |first3=Reema |pages=79–91 |isbn=978-3-030-34148-0 }}</ref> Women with Turner syndrome who wish to raise families but are incapable of conception with their own [[oocyte]]s have the options of adoption or of pregnancy with [[Egg donation|donor eggs]]; the latter has a comparable success rate to donor pregnancy in women with 46,XX karyotypes.<ref name="ajmga1" />

Pregnancy in Turner syndrome is inherently [[High-risk pregnancy|high-risk]]; the [[maternal death]] rate is 2%.<ref>{{cite journal | vauthors = ((Practice Committee of the American Society for Reproductive Medicine)) | title = Increased maternal cardiovascular mortality associated with pregnancy in women with Turner syndrome | journal = Fertility and Sterility | volume = 97 | issue = 2 | pages = 282–284 | date = February 2012 | pmid = 22192347 | doi = 10.1016/j.fertnstert.2011.11.049 | doi-broken-date = 1 November 2024 }}</ref>

Usually, estrogen replacement therapy is used to spur the growth of secondary sexual characteristics at the time when puberty should onset. While very few women with Turner syndrome menstruate spontaneously, estrogen therapy requires a regular shedding of the uterine lining ("withdrawal bleeding") to prevent its overgrowth. Withdrawal bleeding can be induced monthly, like menstruation, or less often, usually every three months, if the patient desires. Estrogen therapy does not make a woman with nonfunctional ovaries fertile, but it plays an important role in assisted reproduction; the health of the uterus must be maintained with estrogen if an eligible woman with Turner Syndrome wishes to use IVF (using donated [[oocyte]]s).{{citation needed|date=September 2021}}

Especially in mosaic cases of Turner syndrome that contains Y-chromosome (e.g., 45,X/46,XY) due to the risk of development of ovarian malignancy (most common is [[gonadoblastoma]]) gonadectomy is recommended.<ref name=Elsheikh>{{cite journal | vauthors = Elsheikh M, Dunger DB, Conway GS, Wass JA | title = Turner's syndrome in adulthood | journal = Endocrine Reviews | volume = 23 | issue = 1 | pages = 120–140 | date = February 2002 | pmid = 11844747 | doi = 10.1210/edrv.23.1.0457 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Gravholt CH, Fedder J, Naeraa RW, Müller J | title = Occurrence of gonadoblastoma in females with Turner syndrome and Y chromosome material: a population study | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 85 | issue = 9 | pages = 3199–3202 | date = September 2000 | pmid = 10999808 | doi = 10.1210/jcem.85.9.6800 | doi-access = free }}</ref> Turner syndrome is characterized by primary [[amenorrhoea]], premature ovarian failure (hypergonadotropic hypogonadism), [[Gonadal dysgenesis|streak gonads]] and infertility (however, technology (especially oocyte donation) provides the opportunity of pregnancy in these patients). Failure to develop secondary sex characteristics (sexual infantilism) is typical.{{fact|date=July 2024}}