Fibroids also called as leiomyomas are benign tumours of the uterus. Fibroids affect approximately 35-77% of reproductive age-women ,although the real prevalence is much higher since many fibroids may be asymptomatic. Fibroids are present in 5-10% of infertile patients, and may be the sole cause of infertility in 1-2.4% .They cause both primary and secondary infertility.
There are three different types of fibroids. Submucous fibroids growing into the cavity of the uterus. Intramural fibroids seen in the wall of the uterus and Subserous fibroids which are outward extensions from the surface of the uterus.
Impact on fibroids on infertility is complex and depends on their size, location, and number.
Mechanism by which fibroids may affect fertility
- Impaired Implantation:
Fibroids, particularly submucosal ones (growing under the uterine lining), can distort the uterine cavity, making it harder for a fertilized egg to implant and for the embryo to develop.
- Distorted Uterine Shape:
Fibroids can change the shape of the uterus, potentially interfering with sperm transport or egg movement.
- Reduced Blood Flow:
Fibroids can decrease blood flow to the uterine lining, which is essential for a successful pregnancy.
- Increased Miscarriage Risk:
Some studies suggest that certain types of fibroids, like intramural fibroids (growing within the uterine wall), might increase the risk of miscarriage.
- Fallopian Tube Obstruction:
In rare cases, fibroids can obstruct the fallopian tubes, preventing eggs from reaching the uterus or sperm from reaching the egg.
Fibroid location is of critical importance in ART (assisted reproductive techniques) outcomes . Submucosal fibroids, in particular, significantly reduce implantation and pregnancy rates of IVF (In Vitro Fertilization). when compared to infertile women without fibroids. Intramural fibroids usually affect implantion and preganacy when the size is large (usually more than 3-4cm).Subserosal fibroids have negligible impact on fertility with ART.
Fibroids and Pregnancy
Fibroids during pregnancy are more likely to be encountered in patients who are 35 years of age and older, nulliparous, or African American . Although most pregnancies with fibroids are uneventful, fibroids increase the risk of pregnancy complications.
During pregnancy, fibroids may grow quickly, causing intense pain. However, fibroid regression after live birth has been demonstrated in 72% of women, with over a 50% reduction in fibroid volume between early gestation and 3-6 months postpartum . A patient with fibroids who is considering pregnancy should be evaluated with a pelvic exam, as well as an ultrasound to delineate the location and size of any fibroid.
Complications occur in approximately 10-40% of pregnancies in the presence of fibroids . Fibroids may contribute to miscarriage, cesarean section, premature labor, abnormal position of the fetus, and postpartum hemorrhage (bleeding post delivery) .Other uncommon complications include pelvic pain due to degeneration of the fibroid, problem to the baby during delivery. The risk of developing complications during pregnancy increases if the fibroids are over 3 cm in size. However, even women with fibroids larger than 10 cm can achieve vaginal delivery approximately 70% of the time.
Treatment : Medical Therapy
Current medical treatment of fibroids includes progestins, oral contraceptives (OCPs), nonsteroidal anti-inflammatory drugs (NSAIDs), tranexamic acid, and gonadotropin-releasing hormone agonists (GnRHa). Some of these medical therapies are limited by undesirable side effects. Progestins, NSAIDs, and OCPs have been used off-label for temporary management of bleeding; however they are unlikely to affect fibroid volume. Most of these treatment modalities are not of proven benefit in a woman trying to conceive.
Surgical Management: Myomectomy- Removal of fibroids
There are different approaches to myomectomy, as it can be done laparoscopically ,abdominally (laparotomy), robotically, or hysteroscopically. However, myomectomies have traditionally been performed by laparotomy. Today, minimally invasive myomectomy approaches have become the preferred approach by patients and providers alike. Myomectomy is most often used for women who desire future fertility. Pregnancy rates have reached 50-60% after both Laparoscopic and abdominal myomectomy, with good obstetrical outcomes.
In summary, fibroids do affect fertility and there treatment especially surgically helps in improving pregnancy rates during treatment of infertility.
