<P> Gestation is the carrying of an embryo or fetus inside viviparous animals . It is typical for mammals, but also occurs for some non-mammals . Mammals during pregnancy can have one or more gestations at the same time (multiple gestations). </P> <P> The time interval of a gestation is called the gestation period . In human obstetrics, gestational age refers to the embryonic or fetal age plus two weeks . This is approximately the duration since the woman's last menstrual period (LMP) began . </P>

Where does the gestation of the fetus occur