Fibroids, which may affect fertility, are the most commonly seen tumours of the female reproductive system of women of reproductive age. They are non-cancerous smooth muscle cell tumours found in about 30 percent of women but only about 20 percent of women display symptoms.
Fibroids are hormonally responsive, growing in the presence of the female hormone oestrogen. They are rarely found in girls who haven’t reached puberty and tend to regress after menopause.
While many women with fibroids do not face fertility issues and have successful pregnancies, certain fibroids are often found in women who do face fertility issues.
The location of fibroid usually determines its impact on fertility. In particular, submucosal fibroids, a form of uterine fibroids where the Fibroids are in the space where the pregnancy stays, are known to negatively affect fertility.
There are many explanations for how fibroids cause infertility in women. Fibroids cause inflammation of the uterine lining and change the local hormonal environment, affecting the implantation of the embryo. Furthermore, large fibroids may interfere with sperm and egg interaction or embryo migration by altering uterine contraction.
It is important to evaluate fibroids to determine their type and the degree to which they may cause infertility.
As stated above, uterine fibroids are benign (noncancerous) tumours of muscle tissue in the uterus. They are also called myomas or leiomyomas. They occur when a single muscle cell in the wall of the uterus multiplies and grows to form a noncancerous tumour.
Fibroids are found in 40 -50% percent of women of reproductive age but are more common in Africans. The exact cause of uterine fibroids is unclear, but there is evidence that it may be a combination of genetic, hormonal, and environmental factors.
Approximately 5 –10 percent of infertile women have fibroids. Their size and location determine whether the fibroids affect fertility. Fibroids that are inside the uterine cavity (submucosal) or very large (>6 cm in diameter) within the wall of the uterus (intramural) may affect fertility.
Most women with fibroids will not be infertile but they and their partners should be thoroughly evaluated to find other problems with fertility before fibroids are treated.
A fertility specialist can help assess if fibroids might be hampering conception. There are several ways uterine fibroids can reduce fertility. If there are changes in the shape of the cervix, it can affect the number of sperm cells that can enter the uterus.
Fibroids can change the shape or size of the uterus and sometimes the cervix (lower part of the uterus). Women may have more than one fibroid tumour but single fibroids are possible. Whether fibroids cause symptoms or require treatment depends on their location, size, and number.
There are three main types of fibroids based on where they are found. Subserosal fibroids are in the outer wall of the uterus (in about 55 percent of cases) while the intramural fibroids are found in the muscular layers of the uterine wall (40 percent). The submucosal fibroids protrude into the uterine cavity (5 percent).
Fibroids can also be connected to the uterus by a stalk (pedunculated), or attached to nearby ligaments or organs, such as the bladder and bowel. Fibroids are rarely found outside the pelvic cavity.
Complications with fibroids are common. They include changes in the shape of the uterus which can interfere with the movement of the sperm or embryo. The Fallopian tubes can also be blocked by fibroids, and they can impact the size of the lining of the uterine cavity. Also, blood flow to the uterine cavity can be affected. This can decrease the ability of an embryo to stick (implant) to the uterine wall or develop.
Generally, fibroids are found in 2 – 12 percent of pregnant women, but not all fibroids get larger or cause problems in pregnancy. If a fibroid grows, it usually does so in the first 12 weeks of pregnancy.
The biggest concern in pregnancy is whether the fibroid will increase the chance of miscarriage or preterm. In some cases, fibroids can outgrow their blood supply and cause severe pain. Hospitalization might be needed.
Also, fibroids can change the baby’s position in the uterus. This can increase the risk for miscarriage, preterm delivery, and cesarean section. How fibroids are managed depends on a woman’s unique situation and her doctor’s recommendations. Surgery is rarely necessary or performed for fibroids during pregnancy. If a woman conceives after having a fibroid removed, she should discuss this with the obstetrician.
The bottom line is that uterine fibroids are common and can affect fertility. They can affect whether sperm and egg meet, they can affect whether an embryo can implant, they can affect whether a pregnancy can continue, and they can affect the growth and positioning of the baby.
Treatment is decided on a case-by-case basis. It is based on the symptoms of fibroids and may improve overall fertility. How and whether you treat your fibroids depends on the severity of your symptoms and your doctor’s recommendations.
