Uterine Fibroids

Uterine fibroids (also known as myomas) are non-cancerous (benign) growths that develop in the uterine muscular wall of some women. They are classified by their location:

  • Intramural: these are found in the uterine muscular wall and can affect fertility if they are over 4cm long
  • Submucosal: they form on the surface of the uterine lining and may affect embryo implantation
  • Subserosal: they are located in the uterine outer lining and do not generally affect fertility

Uterine fibroids are the most common benign pelvic tumor. Approximately 20 percent of women suffer from uterine fibroids during their childbearing years (from their first menstruation to menopause), in particular women over 30.

Fibroids may be microscopic or slowly grow to fill the entire uterine cavity. They may present different shapes and sizes and although they may be single, they are mostly multiple.

These tumors are present in both fertile and infertile women. However, 80 percent of infertility cases related to a uterine factor are due to uterine fibroids that affect the uterine cavity (as is the case of some intramural and submucosal fibroids).

The location of uterine fibroids is highly relevant, as it determines whether or not they can cause infertility by altering sperm transport and/or the embryo implantation process.

In addition, uterine fibroids can cause complications during a woman’s pregnancy, such as:

  • Increased risk of spontaneous miscarriage
  • Fetal growth hindrance
  • Preterm delivery due to an insufficient uterine space
  • Cervical canal obstruction
  • Labor obstruction
  • Postpartum hemorrhage

Uterine fibroids main symptoms

Approximately 25 percent of uterine fibroids are asymptomatic; however, they can also manifest themselves through:

  • Tightness in the lower abdomen
  • Overly abundant menstrual period bleeding
  • Exceedingly long menstrual periods
  • Pelvic cramps or painful menstrual periods
  • Bleeding unrelated to menstrual periods
  • Difficult or painful urination
  • Infertility
  • Recurrent miscarriages

It is important to point out that symptoms associated to uterine fibroids depend on their size, location and number.

What Causes Uterine Fibroids?

Although the specific cause of uterine fibroids is not known, it is believed that their appearance is related to a genetic predisposition. Their growth is also associated with ovarian hormonal activity, particularly with estrogen and progesterone production.

Uterine fibroids appear during a woman’s childbearing years, grow during pregnancy (when there is a higher hormonal level), and disappear after menopause, when hormone levels are lower.

How are uterine fibroids diagnosed?

Ultrasound is the most reliable test for uterine fibroids diagnosis, as it has an accuracy of 95 percent when performed abdominally and 100 percent when performed intravaginally.

It is important that the ultrasound is interpreted by an expert, who will obtain the maximum information from the procedure.

Treatments to achieve pregnancy in patients suffering from uterine fibroids

When trying to achieve pregnancy, treatment of uterine fibroids depends on the woman’s age and, above all, on the size and location of the fibroids.

While subserosal fibroids rarely affect fertility, it is recommended that patients with submucosal or intramural fibroids larger than 5 centimeters consider treatments like In-Vitro fertilization, especially if they are over 35.

In-Vitro Fertilization (IVF) is a particularly effective treatment to achieve pregnancy when the fibroids do not affect the endometrial cavity. While uterine fibroids usually alter sperm transport and embryo implantation, IVF allows our specialists to obtain the eggs directly from the patient’s ovaries. These eggs are fertilized under controlled laboratory conditions to generate embryos with a higher implantation potential which are then transferred back into the patient’s uterus.

Generally, smaller than 7 centimeter subserosal or intramural fibroids do not affect In-Vitro Fertilization results. However, submucosal fibroids larger than 5 centimeter can decrease success rates by affecting the uterine cavity and hindering implantation probabilities.

Therefore, when the fibroids are affecting the endometrial cavity, it is recommended for the patient to undergo a minor surgery known as myomectomy before continuing with an In-Vitro Fertilization treatment.

During this surgery uterine fibroids are removed, causing an increase in pregnancy probabilities and a significant decrease in miscarriage rates. It is highly important to perform a new IVF cycle immediately after the myomectomy, as the likelihood of pregnancy decreases again after the first cycle due to the recurrence of uterine fibroids.