Uterine fibroids are non-cancerous growths that develop in the muscular wall of the uterus. They affect a large percentage of women during their reproductive years, though many experience no symptoms. Fibroids do not automatically lead to difficulty conceiving. The likelihood of interference depends heavily on the fibroid’s size, number, and, most importantly, its location within the uterine structure. Understanding this relationship is the first step toward a successful outcome.
How Fibroids Affect Fertility
Fibroids can impair the reproductive process. Submucosal fibroids, which grow directly into the uterine cavity, are the most problematic type for conception because they physically interfere with embryo implantation. These growths distort the inner lining of the uterus, making it difficult for an embryo to attach and establish a pregnancy, and may increase the risk of early pregnancy loss.
Intramural fibroids, situated within the muscular wall, can also impact fertility if they are large or numerous. These masses may alter blood flow to the endometrium, potentially depriving the developing embryo of necessary oxygen and nutrients. Large intramural growths can also disrupt the subtle muscular contractions of the uterus necessary for the transport of sperm, the egg, and the early embryo. Fibroids located near the uterine horns can physically block the opening of the fallopian tubes, preventing the sperm and egg from meeting.
Diagnosing the Role of Fibroids in Infertility
Determining if a fibroid is causing infertility requires assessment. Diagnostic imaging begins with a transvaginal ultrasound, which maps the size and location of any fibroids present. Because the impact on fertility depends on how much the fibroid protrudes into the cavity, specialized imaging is often necessary for a definitive assessment.
Saline infusion sonography (SIS) is frequently used to provide a clearer view of the uterine cavity’s contour and its relationship to the fibroid. This procedure involves injecting sterile saline into the uterus, allowing the cavity to expand slightly for better visualization. Hysteroscopy, where a thin scope is inserted through the cervix, allows direct visual inspection of the uterine interior to confirm if a fibroid is distorting the implantation space. Physicians typically consider fibroids that significantly distort the uterine cavity or large intramural fibroids—those greater than six centimeters in diameter—as the most likely culprits.
Surgical and Medical Interventions for Conception
If a fibroid is identified as the likely cause of infertility, surgical removal, known as myomectomy, is the primary intervention. The surgical approach is tailored to the fibroid’s location and size. Submucosal fibroids projecting into the uterine cavity are typically removed through hysteroscopic myomectomy, a minimally invasive procedure performed through the cervix without abdominal incisions.
Fibroids located in the uterine wall or on the outer surface may require laparoscopic, robotic, or traditional open abdominal myomectomy. Laparoscopic and robotic methods use small incisions, leading to a faster recovery and less scarring than the open abdominal approach, which is reserved for very large or numerous growths. Following any surgery that cuts through the uterine muscle, a healing period—often three to six months—is required before attempting conception to minimize the risk of uterine rupture during pregnancy.
A short course of Gonadotropin-releasing hormone (GnRH) agonist may be administered for three to four months before myomectomy. This pretreatment temporarily shrinks the fibroids and reduces blood flow, making the surgical procedure technically easier and decreasing blood loss. GnRH agonists are not a long-term solution for conception because the fibroids regrow once the medication is stopped; their use is to facilitate safer surgery. Non-surgical procedures like Uterine Artery Embolization (UAE) are not recommended for women seeking pregnancy due to potential risks to the uterine blood supply and subsequent complications.
Maximizing Pregnancy Chances Without Surgical Intervention
When fibroids are present but do not distort the uterine cavity, or when surgery is not desired, assisted reproductive technology (ART) can be used. Small intramural or subserosal fibroids, particularly those under five centimeters, have little measurable impact on conception rates and do not warrant surgical removal before attempting in vitro fertilization (IVF). Treatment focuses on maximizing the chances of embryo implantation despite the presence of the growths.
During an IVF cycle, careful consideration is given to the placement of the embryo during transfer to avoid areas near a fibroid that may have compromised blood flow or altered receptivity. If a fibroid is large or awkwardly positioned, it may complicate the egg retrieval process by making the ovaries difficult to access. Beyond advanced medical options, optimizing general reproductive health by tracking ovulation and timing intercourse remains important, particularly for those with small, non-interfering fibroids attempting natural conception.