Uterine fibroids are very common non-cancerous (benign) growths that develop in the muscular wall of the uterus. They can range in size from very tiny (a quarter of an inch) to larger than a cantaloupe. Occasionally, they can cause the uterus to grow to the size of a five-month pregnancy.
Most women have no symptoms while others may have painful or heavy periods. If they push on the bladder a frequent need to urinate may occur. They may also cause pain during sex or lower back pain. A woman can have one uterine fibroid or many of them. Occasionally fibroids may make it difficult to get pregnant although this is uncommon.
The exact cause is unclear. However, fibroids run in families and appear to be partly determined by hormone levels. Risk factors include obesity and eating a lot of red meat. Diagnosis may occur by pelvic examination or medical imaging.
Treatment is typically not needed if there are no symptoms. In those with mild symptoms, ibuprofen or paracetamol (acetaminophen) may help. Iron supplements may be needed in those with heavy periods. Medications of the gonadotropin releasing hormone agonist class may decrease the size of the fibroids but are expensive and associated with side effects. If greater symptoms are present, surgery to remove the fibroid or uterus may help. Uterine artery embolization may also help. Cancerous versions of fibroids are very rare and are known as leiomyosarcomas. They do not appear to develop from benign fibroids.
About 20% to 80% of women develop fibroids by the age of 50. In 2013 it was estimated that 171 million women were affected. They are typically found during the middle and later reproductive years. After menopause they usually decrease in size. In the United States, uterine fibroids are a common reason for surgical removal of the uterus.
Schematic drawing of various types of uterine fibroids: a=subserosal fibroids, b=intramural fibroids, c=submucosal fibroid, d=pedunculated submucosal fibroid, e=fibroid in statu nascendi, f=fibroid of the broad ligament
Fibroids, particularly when small, may be entirely asymptomatic. Symptoms depend on the location and size of the fibroid. Important symptoms include abnormal uterine bleeding, heavy or painful periods, abdominal discomfort or bloating, painful defecation, back ache, urinary frequency or retention, and in some cases, infertility. There may also be pain during intercourse, depending on the location of the fibroid. During pregnancy they may also be the cause of miscarriage, bleeding, premature labor, or interference with the position of the fetus.
While fibroids are common, they are not a typical cause for infertility, accounting for about 3% of reasons why a woman may not be able to have a child.The majority of women with uterine fibroids will have normal pregnancy outcomes. In cases of intercurrent uterine fibroids in infertility, a fibroid is typically located in a submucosal position and it is thought that this location may interfere with the function of the lining and the ability of the embryo to implant. Also la
Treatment
Most fibroids do not require treatment unless they are causing symptoms. After menopause fibroids shrink and it is unusual for them to cause problems.Symptomatic uterine fibroids can be treated by:
- medication to control symptoms
- medication aimed at shrinking tumors
- ultrasound fibroid destruction
- myomectomy or radio frequency ablation
- hysterectomy
- uterine artery embolization
Medication
A number of medications may be used to control symptoms. NSAIDs can be used to reduce painful menstrual periods. Oral contraceptive pills may be prescribed to reduce uterine bleeding and cramps.[6] Anemia may be treated with iron supplementation.Levonorgestrel intrauterine devices are effective in limiting menstrual blood flow and improving other symptoms. Side effects are typically few as the levonorgestrel (a progestin) is released in low concentration locally. While most levongestrel-IUD studies concentrated on treatment of women without fibroids a few reported good results specifically for women with fibroids including a substantial regression of fibroids.
Cabergoline in a moderate and well tolerated doses has been shown in two studies to shrink fibroids effectively. Mechanism of action is unclear.
Ulipristal acetate is a synthetic selective progesterone receptor modulator (SPRM) that has tentative evidence to support its use for presurgical treatment of fibroids with low side-effects. Long-term UPA-treated fibroids have shown volume reduction of about 70%.
Danazol is an effective treatment to shrink fibroids and control symptoms. Its use is limited by unpleasant side effects. Mechanism of action is thought to be antiestrogenic effects. Recent experience indicates that safety and side effect profile can be improved by more cautious dosing.
Gonadotropin-releasing hormone analogs cause temporary regression of fibroids by decreasing estrogen levels. Because of the limitations and side effects of this medication it is rarely recommended other than for preoperative use to shrink the size of the fibroids and uterus before surgery. It is typically used for a maximum of 6 months or less because after longer use they could cause osteoporosis and other typically postmenopausal complications. The main side effects are transient postmenopausal symptoms. In many cases the fibroids will regrow after cessation of treatment, however significant benefits may persist for much longer in some cases. Several variations are possible, such as GnRH agonists with add-back regimens intended to decrease the adverse effects of estrogen deficiency. Several add-back regimes are possible, tibolone, raloxifene, progestogens alone, estrogen alone, and combined estrogens and progestogens.
Progesterone antagonists such as mifepristone have been tested, there is evidence that it relieves some symptoms and improves quality of life but because of adverse histological changes that have been observed in several trials it can not be currently recommended outside of research setting. Fibroid growth has recurred after antiprogestin treatment was stopped.
Aromatase inhibitors have been used experimentally to reduce fibroids. The effect is believed to be due partially by lowering systemic estrogen levels and partially by inhibiting locally overexpressed aromatase in fibroids. However, fibroid growth has recurred after treatment was stopped. Experience from experimental aromatase inhibitor treatment of endometriosis indicates that aromatase inhibitors might be particularly useful in combination with a progestogenic ovulation inhibitor.
Uterine artery
Uterine artery embolization (UAE) is a noninvasive procedure that blocks of blood flow to fibroids and thus can treat them.
Long term outcomes with respect to how happy people are with the procedure are similar to that of surgery. There is tentative evidence that traditional surgery may result in better fertility. One review found that UAE doubles the future risk of miscarriage.also appears to require more repeat procedures than if surgery was done initial A person will usually recover from the procedure within a few days.
Uterine artery ligation, sometimes also laparoscopic occlusion of uterine arteries are minimally invasive methods to limit blood supply of the uterus by a small surgery that can be performed transvaginally or laparoscopically. The principal mechanism of action may be similar like in UAE but is easier to perform and fewer side effects are expected.
Myomectomy
Submucosal fibroid in hysteroscopy
Treatment of an intramural fibroid by laparoscopic surgery
After treatment of an intramural fibroid by laparoscopic surgery
There are three types of myomectomy:
- In a hysteroscopic myomectomy (also called transcervical resection), the fibroid can be removed by either the use of a resectoscope, an endoscopic instrument inserted through the vagina and cervix that can use high-frequency electrical energy to cut tissue, or a similar device.
- A laparoscopic myomectomy is done through a small incision near the navel. The physician uses a laparoscope and surgical instruments to remove the fibroids. Studies have suggested that laparoscopic myomectomy leads to lower morbidity rates and faster recovery than does laparotomic myomectomy.
- A laparotomic myomectomy (also known as an open or abdominal myomectomy) is the most invasive surgical procedure to remove fibroids. The physician makes an incision in the abdominal wall and removes the fibroids from the uterus.
Hysterectomy
Hysterectomy was the classical method of treating fibroids. Although it is now recommended only as last option, fibroids are still the leading cause of hysterectomies in the US.Endometrial ablation
Endometrial ablation can be used if the fibroids are only within the uterus and not intramural and relatively small. High failure and recurrence rates are expected in the presence of larger or intramural fibroids.Other procedures
Radiofrequency ablation is a minimally invasive treatments for fibroids. In this technique the fibroid is shrunk by inserting a needle-like device into the fibroid through the abdomen and heating it with radio-frequency (RF) electrical energy to cause necrosis of cells. The treatment is a potential option for women who have fibroids, have completed child-bearing and want to avoid a hysterectomy.Magnetic resonance guided focused ultrasound, is a non-invasive intervention (requiring no incision) that uses high intensity focused ultrasound waves to destroy tissue in combination with magnetic resonance imaging (MRI), which guides and monitors the treatment. During the procedure, delivery of focused ultrasound energy is guided and controlled using MR thermal imaging. Patients who have symptomatic fibroids, who desire a non-invasive tr
eatment option and who do not have contraindictions for MRI are candidates for MRgFUS. About 60% of patients qualify. It is an outpatient procedure and takes one to three hours depending on the size of the fibroids. It is safe and about 75% effective.Symptomatic improvement is sustained for two plus years. Need for additional treatment varies from 16-20% and is largely dependent on the amount of fibroid that can be safely ablated; the higher the ablated volume, the lower the re-treatment rate. There are currently no randomized trial between MRgFUS and UAE. A multi-center trial is underway to investigate the efficacy of MRgFUS vs. UAE.
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