Intrauterine

Intrauterine refers to anything located within the uterus, the muscular organ in the female pelvis that houses and nourishes the developing embryo and fetus during pregnancy. The uterus consists of the body, fundus, and cervix, and contains the uterine cavity lined by the endometrium, with a muscular wall called the myometrium surrounding it.

In obstetrics, intrauterine most often describes a pregnancy developing inside the uterus, as opposed to an ectopic pregnancy, which occurs outside the uterus. The placenta forms within the uterine lining and supports fetal development by exchanging nutrients and waste through the placental circulation and the umbilical cord. Intrauterine growth restriction refers to a condition in which a fetus does not grow to expected size within the uterus and may be associated with various maternal, placental, or fetal factors.

The term also appears in the names of medical devices and procedures. An intrauterine device (IUD) is a long-acting reversible contraceptive placed inside the uterine cavity. Intrauterine insemination (IUI) is a fertility treatment in which semen is inserted directly into the uterus to enhance the chances of fertilization.

Other uses describe conditions or events within the uterus, such as intrauterine infection or intrauterine fetal death, where complications arise in the uterine environment during pregnancy. Overall, intrauterine denotes location inside the uterus and is used across obstetrics and reproductive medicine.