FEMALE ANATOMY: THE UTERUS

This is a muscular organ, which has a cavity. Its usual (non-pregnant) size in an adult woman is about as big as a large apricot, or a little peach. It may become bigger because of benign (non-cancerous) tumours of the muscle wall, called fibroids or polyps, or because it is housing a baby or, less commonly, because of cancerous growths.

The uterus has a lining, called the endometrium (endo = inside, metrium is to do with the uterus). This lining becomes thicker when the right hormones, mainly oestrogen and progesterone, are in the right levels in the blood stream, and is shed when the hormonal levels change. This shedding is called menstruation.

When you are pregnant the uterus grows to accommodate a foetus and a placenta. After delivery of the baby it returns to its pre-pregnancy size. This is called “involution” of the uterus. Involution may take about six weeks.

Other fascinating facts about the uterus include the fact that usually it is tilted forward (called “anteverted”), and in about 20 per cent of women it is tilted backward (called “retroverted”). If it is pointing upward it is called “axial”. All of these positions are normal variations. Usually the uterus is “mobile”, which means that it can be moved from one position to another; that it is not

tethered down to surrounding structures. An immobile uterus may result from scarring, or other structures blocking the way, like cysts. Whether or not your uterus is mobile or anteverted, etc., is usually of no significance in the day-to-day workings of the apparatus.

Some women have a uterus which is a different shape, not the typical peat shape. Some of them have two compartments (sometimes with a double cervix and even two vaginas). Some uteri are heart shaped. They have just developed this way, and usually function normally.