Editing Down syndrome (section)

===Fertility===
Males with Down syndrome usually do not father children, while females have lower rates of [[fertility]] relative to those who are unaffected.<ref name=Prad2006/> Fertility is estimated to be present in 30–50% of females.<ref name=Nel2010/> [[Menopause]] usually occurs at an earlier age.<ref name=Malt2013/> The poor fertility in males is thought to be due to problems with [[spermatogenesis|sperm development]]; however, it may also be related to not being sexually active.<ref name=Prad2006>{{cite journal | vauthors = Pradhan M, Dalal A, Khan F, Agrawal S | title = Fertility in men with Down syndrome: a case report | journal = Fertility and Sterility | volume = 86 | issue = 6 | pages = 1765.e1–1765.e3 | date = December 2006 | pmid = 17094988 | doi = 10.1016/j.fertnstert.2006.03.071 | s2cid = 32384231 | doi-access = free }}</ref> Without [[preimplantation genetic diagnosis|assisted reproductive technologies]], around half of the children of someone with Down syndrome will also have the syndrome.<ref name=Prad2006/><ref name=Rubin2013/>