The woman who is having pregnancy is called pregnant i.e. gravid. One who is first time pregnant is known as ‘primigravida’ or ‘gravida 1’ and later it is increased in no. like mother with second time pregnancy will termed as ‘gravida 2’ and so on.
The other name for it is Gestation. It is period of development of fetus in uterus of female. There are chances of having more than one gestation or multiple gestation i.e. two (twins) or three (triplets) fetus in uterus.