The uterine fibroid or fibroids are non – cancerous, benign pelvic tumors that grow around the uterus and occasionally in the cervix. These abnormal masses of muscle tissue originate in the cells of the myometrium or wall of the uterus. Due to its location, it can be thought that the ability to become pregnant is affected, but as we will see, this fact will depend on several factors.

The exact cause of uterine fibroids is not known, although it is believed that they are caused by hormonal changes such as those that occur during pregnancy, where estrogen levels are altered. It is also thought that the genetic factor can influence its appearance.

Fibroids can be very small, only visible through a microscope, although they can reach a large size and even occupy the entire uterus. In most cases, several uterine fibroids develop.

The Fibroids are classified according to their location as:

• Subserosal fibroids: They are located just under the outer covering of the uterus and generally grow towards the outside of the uterine cavity, giving the uterus a bulging appearance, but they do not prevent pregnancy or childbirth. They represent approximately 55% of fibroids. From a subserous myoma, a pedunculated myoma can grow in the form of a long stalk that is suspended in the pelvic cavity.
• Intramural fibroids: They grow in the muscular wall of the uterus, and can cause a deformation of the normal architecture of the uterus. Approximately 40% of uterine fibroids are of this type and it is not usually directly related to problems conceiving.
• Submucosal fibroids: They are located under the surface of the uterine lining, growing into the uterus, causing atrophy or destructuring of the lining of the uterine endometrium. They are 5% of the cases of uterine fibroids and they are the ones that can present more infertility problems. From a submucosal myoma, a pedunculated myoma can grow in the form of a long stalk through the cervix into the vagina.

Fibroids are relatively common in women. A 20% of women may have fibroids in the uterus during her fertile years, and up to 50% of the women may have around 50 years. These fibroids are very rare in those under 20 years of age. In the vast majority of cases, these fibroids are benign tumors. Only 1 in 10,000 cases has a malignant tumor, called a leiomyosarcoma.

Many fibroids do not present any symptoms, although the most frequent symptoms associated with uterine fibroids are:

• Bleeding between periods.
• Heavy menstrual bleeding, sometimes with blood clots.
• Menstrual periods that may last longer than normal.
• Need to urinate more often.
• Cramping or pain during periods.
• A feeling of fullness or pressure in the lower abdomen.
• Pain during sexual intercourse.

To detect and find these fibroids, the gynecologists’ will perform a simple pelvic exam looking for changes in the shape of the uterus. Other methods that can be used to diagnose and find fibroids in the uterus include a pelvic ultrasound, MRI, hysteroscopy, or endometrial biopsy.

Fibroids in the uterus can contribute to an infertility problem, and have also been associated with a possible cause of repeat miscarriages. When fibroids are of the subserous type, the most common where they develop outside the uterus, they do not prevent pregnancy. Intramural fibroids, although they can be large (which may involve a caesarean section as it blocks the birth canal), they are not linked to infertility problems either.

The submucosal type fibroid are directly related to the difficulty of getting pregnant. Being located in the endometrium, they can block the entrance of the ovum to the fallopian tubes or make it difficult for the embryo to implant. In cases where pregnancy occurs, a spontaneous abortion can occur, usually during the first trimester.

Treatment for these submucosal fibroids in the uterus consists of an intervention called operative hysteroscopy. This procedure is performed by introducing an optical guide through the vagina into the uterus. This tool sends images of the inside of the uterus to examine the inside. Using the same guide, these uterine fibroids are detected and removed. Hysteroscopy is performed under sedation and usually lasts between 15 minutes and 1 hour, depending on the degree of tissue to be removed. Once free of these fibroids, the woman should be ready to become pregnant.