Fibroids are benign tumours of the muscle of the uterus (womb). They are one of the most common tumours found in women during their reproductive years, although their place in causing infertility has been somewhat controversial. Fibroids are the single most common cause for hysterectomy, being responsible for somewhere between 20% and 77% of all hysterectomies performed. Fibroids can be found in up to half of all women undergoing a post mortem examination. They are more common in women who have not had children, women who are overweight and black women. Only about a quarter of women with fibroids will experience any symptoms. These may include heavy and painful periods, pain with sex, infertility or urinary or bowel symptoms caused by local pressure due to the fibroids. In women who do conceive, the fibroids may cause complications in pregnancy, including miscarriage, premature labour and pain due to infarction or red degeneration (caused by inadequate blood supply). Very rarely, a fibroid can undergo malignant change, particularly if the fibroid is very large or rapidly increases in size.
The diagnosis is usually made on the basis of a history of the symptoms described above or as an incidental finding at routine vaginal examination at the time of a cervical smear test. In women being investigated for infertility, fibroids are often found at a routine ultrasound scan. An ultrasound scan is an important investigation since it can also differentiate between an ovarian cyst or other pelvic tumour. An MRI scan, in which powerful magnets are used to look at the structure of tissues, is also very useful but rather expensive. It is particularly helpful in distinguishing between fibroids and adenomyosis (a condition related to endometriosis) which may be much more difficult to treat, and can cause similar problems.
The site of the fibroid will often influence the symptoms experienced and, to some extent, the treatment. Fibroids can be either submucous, intramural, subserous or pedunculated, as shown below.
Submucous and intramural fibroids are more likely to cause painful or heavy periods and problems with implantation or miscarriage. Subserosal and pedunculated fibroids are more likely to cause problems with local compression and pain, especially during pregnancy. An MRI scan of an intramural fibroid is shown above.
Fibroids should be treated if they are causing symptoms, as described above, or in certain cases if a woman is trying to conceive, although medical opinion is divided on whether or not fibroids should be treated to improve the chances of conceiving. Sometimes the periods can be so heavy that women develop quite severe anaemia. Most doctors would also agree that, in the absence of any symptoms, pedunculated fibroids are unlikely to cause major problems with conception, but submucous fibroids probably will cause delays in conceiving and miscarriages in those women who do conceive. Intramural and subserosal fibroids are rather more of a grey area. The decision about whether or not to treat them really depends on the woman's age, how large the fibroids are, whether she has had miscarriages before and whether the uterus is distorted by their presence. The age is important, since fibroids tend to continue to grow under the influence of oestrogen and it is true to say that in younger women they are easier to remove whilst they are small. Older women should beware of potential delays in waiting for surgery, particularly in the NHS. You should also be aware that you are likely to be advised not to conceive for up to three months after the operation. In these circumstances the balance of probabilities may influence your doctor not to recommend surgery, in favour of earlier fertility treatment.
A recently published study from Monash University in Australia compared the pregnancy rates following IVF treatment for women known to have fibroids at the time of treatment with those for women without fiboids. There was no difference in the pregnancy rates when the fibroids were pedunculated or subserosal, but when they were intramural or submucosal the pregnancy rates were up to 50% less than for normal women. This report is beginning to influence more doctors to treat fibroids prior to fertility treatments.
Treatment depends on the size and site of the fibroids. The options include:
Hormonal therapy can be useful for women who are close to the menopause and wish to avoid surgery, but hormonal treatment is unlikely to be of any benefit in women who wish to conceive and causes unnecessary delays.
Submucous fibroids can usually be treated by hysteroscopic resection provided they are less than 10 cm in diameter. Usually a gonadotrophin releasing hormone analogue GnRH-a (as used for pituitary suppression in IVF programmes) will be given by either nasal inhalation, or subcutaneous injection either daily or monthly for between two and eight weeks prior to surgery. This will cause low levels of oestrogen and may cause some shrinkage of the fibroid together with thinning of the endometrium, which will make the operation easier.
The fibroid is resected using a wire loop passed down an operating hysteroscope, an instrument of up to 9mm in diameter which is introduced into the uterus via the cervix after it has been gently dilated (stretched) to allow the hysteroscope to pass. A new diathermy instrument called a Versapoint and some lasers can be used in a similar fashion, to either cut through the base of the fibroid or, at higher power settings, they can completely vaporise smaller fibroids.
Hysteroscopic procedures are quite straightforward provided the surgeon has had proper training, but there are some complications of which you should be aware. As with any other operation, there is a risk of infection and bleeding. There is also a risk that the instrument may perforate the uterus and damage the bowel or blood vessels of the pelvis with potentially catastrophic results. Thankfully these complications are now very rare, since thorough training programmes have been introduced. The other problem with hysteroscopic procedures is the absorption of the distension medium (fluid which is used to distend the cavity of the uterus to ensure a good view) through small blood vessels which are inevitably cut during the operative procedure. This absorption can cause disturbance of the sensitive salt and water balance of the body causing headaches, nausea and in some cases swelling of the brain. These effects are usually minor provided no more than 1 litre of fluid enters the circulation. In some cases, particularly with large fibroids the resection may have to be completed in two stages due to excessive fluid absorption.
The surgical removal of fibroids is called a myomectomy. Intramural and subserous fibroids up to 10 cm in diameter can be removed by laparoscopic myomectomy, through two small incisions 10 mm in length, one in the umbilicus (navel) and the other a little lower down in the midline of the abdomen. Two smaller incisions only 5mm in length are made, one on either side of the abdomen about three inches from the midline. Presently only a handful of surgeons in this country offer this procedure which takes much longer and is more challenging than conventional surgery. The picture below, on the left, is of an intramural fibroid of 5 cm in diameter prior to removal laparoscopically. The picture on the right shows the appearance after removal and laparoscopic repair.
The principal difficulty with laparoscopic myomectomy is the repair of the uterus after the fibroid has been removed. This is done using laparoscopically applied sutures which requires considerable experience, training and a great deal of patience. After removal of the fibroid, it has to cut into thin strips of 10mm in diameter so that it can be removed, piecemeal through one of the laparoscopic ports. This is done with an instrument called a morcellator, seen in the foreground of the picture below. It consists of two concentric cylinders, the inner one has a sharp blade at the end and is driven to rotate by an electric motor.
Results for laparoscopic surgery performed in the best centres are comparable with conventional surgery. The advantages as far as the woman is concerned are a shorter spell in hospital, less post-operative pain and a faster return to work. However, not all fibroids are suitable for laparoscopic management and some may require conventional surgery, especially if there are three or more discreet fibroids present, or the fibroid is positioned such that access is restricted.
A conventional myomectomy is performed through a low, horizontal or transverse skin incision along the bikini line (some fibroids are too large for this approach and may need a longitudinal or vertical incision) . The muscle of the uterus is incised and the fibroid shelled out. The muscle must then be repaired with sutures taking care to handle the tissue as little as possible to avoid the risk of adhesion formation. Apart from adhesions there is a risk of haemorrhage and infection in the short term, and rupture of the uterus in the longer term during pregnancy and labour. Many obstetricians will recommend a caesarean section after myomectomy for this reason. Some fibroids can be very vascular, and particularly in larger cases, and where the fibroid is close to the main artery supplying the uterus, women should be aware that there is a risk of such heavy bleeding that their surgeon may be required to perform a hysterectomy. This is only done as a last resort, as a life saving procedure in cases of catastrophic haemorrhage. In such cases the fibroids are usually so large and the uterus so distorted that pregnancy would have been impossible anyway, however myomectomy is not a procedure to be undertaken lightly and should only be performed by experienced surgeons.
Fibroids are a common condition, causing symptoms in about 25% of cases. Their effect on fertility is debatable. A range of conservative treatments now exists for the management of these symptoms, some of which may improve the chances of conceiving, either following fertility treatment or natural conception. Careful investigation and evaluation is recommended, together with a full and frank discussion with your fertility specialist in order that an appropriate management plan can be developed, taking into account your age, symptoms, desire for further pregnancies and social factors such as the demands of a busy career and/or family.
Parts of this page have been reproduced from an article originally published in the magazine Pathways to Pregnancy