The uterus is composed of a thick layer of smooth muscle (myometrium) that surrounds the lining (the endometrium) into which the embryo implants. Approximately 10-20% of all reproductive age women will develop benign growths of the myometrium, referred to as fibroid tumors (myomas). Estrogen stimulates their growth and these tumors are rarely malignant (cancerous). They can be located in the wall of the uterus (intramural), on the outside of the uterus (subserosal), within the uterine cavity (submucosal), on a thin stalk (pedunculated) or a combination of the above.
Presentation, Symptoms and Signs Associated with Uterine Fibroids
Fibroids, even large ones, can be present without any symptoms at all. However, they can also cause a variety of symptoms depending on their size, location and the absence or presence of complications such as torsion (twisting) or degeneration (fibroid grows to an extent that it starts running out of its blood supply). The most common symptoms are heavy cyclical menstrual bleeding (menorrhagia) accompanied by menstrual pain (dysmenorrhea). Sometimes, especially when a fibroid protrudes into the uterine cavity, it can cause erosion of the endometrial lining and produce irregular or continuous bleeding (meno-metrorrhagia). Other possible symptoms include pain with deep penetration during intercourse (dyspareunia), bladder irritability, rectal pressure, constipation and painful bowel movements (dyschezia).
Effect of Fibroids on Reproduction
For the most part, only those fibroids that impinge upon the endometrial cavity (submucosal) or multiple fibroids in the muscle layer without a direct impact may adversely affect fertility. Exceptions include large intramural fibroids that block the openings of the fallopian tubes into the uterus, and where multiple fibroids cause abnormal uterine contraction patterns. Surgery to treat fibroids can also affect fertility in several ways. If the endometrial cavity is entered during the surgery, there is a possibility of post operative adhesion formation within the uterine cavity. This should always be checked by a hysteroscopy or fluid ultrasound (hydrosonography) prior to beginning fertility treatment. Because myomectomy can be bloody, there is a high likelihood of abdominal adhesion formation, which could encase the ovaries, preventing the release of the eggs or blocking the ends of the fallopian tubes. For this reason it is important that experienced surgeons or reproductive endocrinologists, who are familiar with surgical techniques to limit blood loss and prevent adhesion formation, perform myomectomy.
In some cases multiple uterine fibroids may also deprive the endometrium of blood flow, that the delivery of estrogen to the uterine lining (endometrium) is curtailed to the point that it cannot thicken enough to support a pregnancy. This can result in early 1st trimester miscarriages (prior to the 13th week of pregnancy). Large or multiple fibroids, by curtailing the ability of the uterus to stretch in order to accommodate the spatial needs of a rapidly growing pregnancy, may precipitate recurrent 2nd trimester miscarriages (beyond the 13th week) and/or trigger the onset of premature labor.
Sizable fibroids are usually easily identified by simple vaginal–pelvic bimanual examination. However, even the smallest fibroid can be identified by transvaginal ultrasound. Sometimes it is difficult to tell if a fibroid is impinging on the endometrial cavity. In such cases, a hysteroscopy (where a telescope-like instrument, inserted via the vagina into the uterine cavity) or a hydrosonogram (where salt water distends the uterine cavity, allowing for examination of its contour and inner configuration) can help distinguish between intramural and submucosal fibroids. Magnetic Resonance Imaging (MRI) can be used to distinguish between fibroid tumors and a related condition called adenomyosis, in which diffuse or localized foci of endometrium is found within the myometrium. Given the often-diffuse nature of adenomyosis, it is difficult to remove surgically. This contrasts with fibroid tumors, which are well defined and are usually easily removed.
Surgical Treatment of Fibroid Tumors
The treatment of fibroid tumors in infertility patients is surgical removal (myomectomy). Small, asymptomatic fibroids that do not impinge upon the endometrial cavity will usua