ABNORMAL ANATOMY OF THE UTERUS
The uterus (womb) is a reproductive organ tucked away in your pelvis. It measures 7.5cm long, 5cm wide and 2.5cm deep. The uterus is hollow with thick and muscular walls. The lower portion of the uterus extends down into the vagina and is called the cervix. The upper portion is known as the fundus and it is where fertilised egg grows into a baby. Two fallopian tubes are connected to an egg-filled ovary on each side. The eggs make its way into your uterus on either side at the top.
WHERE IS THE UTERUS POSITIONED?
- Anteverted/anteflexed: The uterus leans forwards over the top of the bladder. This is the normal position of the uterus.
- Tilted uterusor retroverted uterus: The uterus leans away from the bladder. It’s not strictly speaking an abnormality as it affects the position.
WILL I BE ABLE TO GET PREGNANT IF I HAVE AN ABNORMAL UTERUS?
It largely depends on the abnormality. However, uterine abnormalities normally do not affect your ability to become pregnant. Some women do not even realise they have a tilted uterus.
A tilted uterus can be found in 1 out of 6 women. It does affect your chances of getting pregnant. The ability of the sperm getting to your fallopian tubes through your uterus has nothing to do with the position.
WHAT IS AN ABNORMAL UTERUS?
A small percentage of women have a uterus that is different in structure rather than position. This is considered an abnormality of the uterus. It’s thought that somewhere between 1 woman in 100 and one woman in 20 has a uterine abnormality in the general population.
It’s difficult to pin down numbers as only some women will have their abnormality identified. An estimated of 1 in 13 women with uterine abnormalities seek help for infertility. Meanwhile, the rates are as high as 1 in 3 women with a history of late miscarriage.
WHAT ARE THE DIFFERENT TYPES OF UTERINE ABNORMALITIES?
- Agenesis: Extremely rare. It is believed to affect only 1 woman in 4,000 and 1 woman in 10,000 respectively. It occurs when the vagina is very short or does not form properly. There may be a very small uterus or none at all. It is normally identified when a girl doesn’t start her periods.It can also make sex very uncomfortable. Surgery is used to treat this condition. If you have agenesis of the uterus, you should be offered counselling too. Surrogacy is the only way for a woman with agenesis to have a baby.
- Uterus didelphys: The uterus has two inner cavities which may lead to its own cervix and vagina. This means that there are two cervix and two vaginas. This is an uncommon abnormality that affects about 1 in 350 women. It is possible to conceive and have a straight forward pregnancy with this abnormality.
- Unicornuate uterus: The uterus is half the size of a normal uterus and there is only one fallopian tube connecting to it. It is described as a uterus with one horn due to the shape.
This is a rare abnormality that affects about 1 in 1,000 women in the general population. This abnormality develops in the earliest stages of life when the tissue that forms the uterus does not grow properly. You probably have two ovaries is you have this condition but only 1 will be connected to your uterus.
The good news is that as long as there is 1, healthy, developed fallopian tube, it‘s perfectly possible to conceive. With that said, it does increase your chances of having a miscarriage.
- Bicornuate uterus: The uterus is shaped like a heart with a deep indentation at the top instead of a pear shaped uterus. It is described as a uterus with two horns due to its shape. It’s believed that fewer than 1 in 200 women in the general population have this condition. This abnormality shouldn’t your fertility. However, you have a higher risk of miscarriage.
- Septate uterus: The inside of your uterus is divided by a muscular or fibrous wall (septum). In the general population, about 1 in 45 women have this abnormality. The septum may only extend part way into the uterus (partial septate uterus) or it may extend as far as the cervix (complete septate uterus). Partial septates are more common than complete septates. This abnormality may make it harder for you to conceive and may also increase your risk of miscarriage.
- Arcuate uterus: Looks more like a normal uterus but it has a dip or slight indentation at the top. This abnormality is common and affects about 1 in 25 women in the general population. It doesn’t normally affect the chances of conceiving.
Often, there are no medical or reproductive problems in many women with a congenital uterine anomaly. These anomalies may increase the risk of a miscarriage or a premature delivery. If a woman has a septate uterus and has had miscarriages, surgical treatment will be required to improve her chances for a successful pregnancy.
Most of the times, women with uterine abnormalities don’t experience symptoms and may not even discover that they have an abnormal uterus until they have a routine pelvic exam or an ultrasound.
When the symptoms occur, women may experience:
- Never having had a period
- Recurrent miscarriages
- Preterm labour
- Abnormal positioning of the baby during pregnancy or labor
- Pain when inserting a tampon
- Pain during sex
- Pain with menses
Additionally, a uterine abnormality can block menstrual blood from exiting the body due to incomplete development of the vagina or uterus. This normally causes monthly abdominal pain with or without external bleeding.
Currently, there are no non-surgical treatments for congenital uterine anomalies. Surgical treatment of congenital uterine anomalies depends on the particular anomaly and the woman’s reproductive history.
Many women with uterine anomalies do not require surgery. Only when pain, miscarriage, or infertility is an issue, you may be recommended surgically correcting the anomaly. Minimally invasive techniques such as laparoscopy or hysteroscopy are enough to correct uterine anomalies in most cases.
In the instance of a unicornuate uterus, if the other side of the uterus is intact and functional, the obstruction can be removed.
- History taking and physical examination: Suspicion that a congenital uterine anomaly is present may arise after your obstetrician or gynaecologist performs a complete medical history and physical examination.
- 3D ultrasound scan: This may reveal an abnormality.
- Magnetic resonance imaging (MRI): This is considered to be the best way of scanning for abnormalities. It uses strong magnetic fields and radio waves to create a detailed image of the inside of your body. This examination is only used when you and your doctor are sure that you are not pregnant.
- Special X-ray: Special X-ray with a dye known as hysterosalpingographywill be used. The dye enters your body through a fine tube (catheter) and flows into your uterus and fallopian tubes. This will give your doctor a clear picture of how well your uterus and fallopian tubes are working.
- Laparoscopy: This procedure enables your doctor to have a look at your uterus and fallopian tubes. A small cut will be made in your belly button where a tube with a camera (endoscope) will be inserted through the cut to examine you internally.