Editing Gestation (section)

{{Short description|Period during the carrying of an embryo}}
{{See also|Pregnancy}}
[[File:Feminology; a guide for womankind, giving in detail instructions as to motherhood, maidenhood, and the nursery (1902) (14761381441).jpg|alt=Drawing of a sagittal cross-section of a fetus in the pregnant parent's amniotic cavity.|thumb|upright|Drawing of a fetus in utero.]]
'''Gestation''' is the period of [[prenatal development|development]] during the carrying of an [[embryo]], and later [[fetus]], inside [[Viviparity|viviparous]] [[animals]] (the embryo develops within the parent).<ref>{{cite journal | vauthors = Mckay RJ, Lucey JF | title = NEONATOLOGY | journal = The New England Journal of Medicine | volume = 270 | issue = 23 | pages = 1231–6 CONTD | date = June 1964 | pmid = 14132827 | doi = 10.1056/NEJM196406042702306 }}</ref> It is typical for [[mammal]]s, but also occurs for some non-mammals. [[Pregnancy (mammals)|Mammals during pregnancy]] can have one or more gestations at the same time, for example in a [[multiple birth]].<ref>{{cite journal | vauthors = Keith L, Oleszczuk JJ | title = Iatrogenic multiple birth, multiple pregnancy and assisted reproductive technologies | journal = International Journal of Gynaecology and Obstetrics | volume = 64 | issue = 1 | pages = 11–25 | date = January 1999 | pmid = 10190665 | doi = 10.1016/S0020-7292(98)00230-6 | s2cid = 31814692 }}</ref>

The time interval of a gestation is called the ''[[gestation period]]''. In [[obstetrics and gynecology|obstetrics]], ''[[gestational age]]'' refers to the time since the onset of the last [[Menstruation#Onset and frequency)|menses]], which on average is [[Human fertilization#Fertilization age|fertilization age]] plus two weeks.<ref>{{cite journal | vauthors = Liao JB, Buhimschi CS, Norwitz ER | title = Normal labor: mechanism and duration | journal = Obstetrics and Gynecology Clinics of North America | volume = 32 | issue = 2 | pages = 145–64, vii | date = June 2005 | pmid = 15899352 | doi = 10.1016/j.ogc.2005.01.001 }}</ref>