A number of readers have written asking me to write about fibroids and in particular about the advisability of undergoing a treatment called uterine artery embolisation.
What are fibroids? They are benign growths of the smooth muscle of the womb. Studies suggest up to 75 per cent of women have fibroids but only one in four women experiences problems with them.
Most fibroids cause no problem, but when they do symptoms can be classified into three categories: abnormal bleeding, pain and problems with reproduction.
Fibroids are a leading cause of heavy or overly frequent periods. Excessive bleeding can lead to iron-deficiency anaemia and is a source of social embarrassment for the woman. It has also been shown to affect productivity. Fibroids which grow into the cavity of the womb - called submucosal - are most likely to cause excessive bleeding.
Benign uterine growths can grow to a substantial size. It is not uncommon for them to cause the womb to reach a size equivalent to a 20-week pregnancy. Not surprisingly, fibroids of this size cause pressure on other parts of the pelvis. Those that grow forward will put pressure on the bladder giving rise to urinary symptoms. Posterior growth - pressurising the colon - can cause constipation.
How do fibroids affect a woman's ability to have children? If they protrude into the womb's cavity, they can cause infertility. Those growing into the uterine wall have recently been implicated in fertility problems. Having a fibroid growing under the site where the placenta attaches may cause a miscarriage. Fibroids can also cause premature labour.
The growth of fibroids is directly linked to the sex hormones oestrogen and progesterone. Most women are in their 30s or 40s before fibroids cause symptoms, which tend to settle again with the onset of the menopause. Having one or more pregnancies seems to decrease the risk of developing fibroids. The pill appears to be protective also.
Smoking has also been shown to decrease the risk of fibroids - one of the few positive associations reported for what is otherwise a life-threatening habit.
Can fibroids turn cancerous? Very rarely; figures suggest a risk of two to three per 1,000.
Treatment options are quite varied and, not surprisingly, depend on where exactly the growth is. Hysterectomy may be the straightforward choice for women who have completed their families. For those who may want to become pregnant again, individual fibroids can be removed while conserving the womb - a process called myomectomy.
It may be possible to remove fibroids which have grown outwards from the womb wall using a laparoscope - a telescope which is put in place through the belly button.
Growths into the cavity of the womb may be removed using a hysteroscope - a similar instrument but one which is introduced via the neck of the womb.
Drugs have a role in preparing the patient for surgery by shrinking the fibroids preoperatively. Unfortunately, when a woman stops taking the hormonal agent there is immediate regrowth. They are not suitable for long term use because of their side effects.
FINALLY, what about the latest treatment option? Uterine artery embolisation (UAE) is a minimally invasive technique in which a catheter is placed in both uterine arteries - a procedure similar to having an angiogram for heart disease. Performed under local anaesthetic as a day case, small particles (emboli) are injected into the vessels which supply the fibroids. Deprived of their blood supply, they shrink in size.
One in 10 women currently opts for UAE in the United States. Gynaecologists here and in Britain are more cautious about its use. A Dublin gynaecologist pointed out that the UK regulatory body for new medical technology has recommended that UAE be carried out only in research centres. There has been a death in Britain from the procedure, which is similar to causing a clot to travel down a blood vessel. Reports of significant post-procedure pain have also dampened enthusiasm on this side of the Atlantic.
It seems likely that UAE will have a place for the treatment of a small percentage of patients whose future fertility is a critical factor, although one study reported a one in 20 risk of permanent loss of periods.
So to those readers who asked about UAE, my advice for the present is "Caveat Emptor". Let's wait for more research and the results of long-term studies into the treatment.
•E-mail Dr Muiris Houston at mhouston@irish-times.ie or leave a message at 01-6707711 ext 8511. He regrets he cannot reply to individual medical problems