In utero refers to the time when a fetus is in the uterus of a pregnant female. It is a Latin term that means "in the womb" or "in the uterus". The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. The main function of the uterus is to nourish the developing fetus prior to birth. The term "in utero" can be used to describe a variety of things related to the fetus and pregnancy, such as diseases acquired in utero, in utero diagnosis, and exposure to endocrine-disrupting chemicals in utero.