How do fibroids affect fertility?

Uterine fibroids are very rarely cancerous (a type of tumor called leiomyosarcoma happens in fewer than one out of every 1,000 fibroids), but that doesn't mean benign tumors can't cause problems [source: USDHHSOWH]. Only between 10 and 20 percent of women have symptoms, but those who do often experience painful periods, sometimes with heavy bleeding (known as menorrhagia) and clots, bleeding between periods, pain during intercourse, a feeling of fullness or pressure in the lower abdomen and lower back pain [source: GUH-DVIR].

While many uterine fibroids are so small they go unnoticed, some fibroids may grow as big as a grapefruit, or bigger -- those that grow into sizable tumors (several inches in diameter, compared to fibroids that never grow bigger than an apple seed) are rare, and may begin to put the squeeze on some internal organs because of the space they take up, sometimes causing pressure and more frequent and more urgent urination, as well as constipation for some women [source: USDHHSOWH].

The location of the fibroid -- or fibroids, as there could be more than one growing at a time -- may also have a negative impact on a woman's fertility. Some studies show that fibroids may increase complications during pregnancy, including increasing the risk of placental abruption (when the placenta prematurely detaches from the uterine wall) as well as increasing the risk of premature labor and delivery. Women with fibroids are also six times more likely to deliver via cesarean section (C-section) than women without [sources: USDHHSOWH, Puscheck].

Fibroids have also been implicated in conception problems such as implantation failure, as well as an increased risk of miscarriage -- in fact one study found women with fibroids may have as much as a 14 percent risk of miscarriage compared to a 7 percent risk in women without fibroids [source: Lee]. Let's talk more about how and why fibroids may affect a woman's fertility, next.

While no study has yet been able to pinpoint specific evidence as to why some women with fibroids seem to have a higher than normal risk of miscarriage or trouble conceiving, multiple studies have found there may be an association between fibroids and infertility -- researchers just haven't found what that is yet.

Some research indicates submucosal fibroids -- those are the type that grow in the uterus -- may twist or misshape the uterus, causing conception and pregnancy complications. Other theories suggest that the location of the fibroid(s) may play a role in early miscarriage, and that fibroids growing in the uterus or within the uterine wall may impact blood flow to the placenta and cause an irritable uterus.

Treatment options vary depending upon the age of the patient, the severity of the symptoms and the size of the tumor(s), as well as whether or not the woman wants to try to have children. For many women, over-the-counter pain relievers may be the only thing needed to minimize symptoms. For others, hormone therapy may be the right choice to stop fibroid growth.

Surgical interventions are typically needed for fibroids that cause moderate to severe symptoms. Women with severe symptoms and/or chronic fibroids who have already had children or who aren't interested in having children often undergo a hysterectomy, which removes the uterus and is 100 percent effective in treating fibroids and their symptoms. These women also may consider a procedure called endometrial ablation, which destroys the uterine lining via heat, laser, freezing or microwaves, or uterine fibroid embolization (UFE) or uterine artery embolization (UAE), which block blood flow to the fibroids, causing them to shrink.

Treating fibroids in women who hope to have children some day and wish to preserve their fertility is a little different, and the treatment methods used in such cases are minimally invasive and aimed at preserving the uterus as much as possible.

Currently, a procedure called myomectomy, a minimally invasive surgical removal of fibroids, is used to treat women who still wish to have children. Recent findings show that women who choose to have fibroids removed via a myomectomy risk having new fibroids develop (which happens to about one-third of women who undergo the procedure), but you can't argue with the success rate: It's estimated that as many as 40 to 60 percent of women who have undergone a myomectomy to remove fibroids have gone on to become pregnant post-treatment [source: WebMD, GUH-DVIR].