Uterine fibroids, or leiomyomas, are common noncancerous growths of the uterus that can significantly impact fertility and the outcomes of in vitro fertilization (IVF). According to the American Society for Reproductive Medicine (ASRM), fibroids that distort the uterine cavity, known as submucosal fibroids, are most likely to impair embryo implantation and increase the risk of miscarriage. Patients undergoing IVF should undergo a thorough uterine evaluation to determine if surgical intervention is necessary to improve success rates.
Impact of Fibroid Location on IVF Success
Not all fibroids affect pregnancy outcomes equally. The primary factor determining clinical significance is the location of the fibroid relative to the uterine wall.
- Submucosal Fibroids: These project into the uterine cavity. Clinical data indicates these growths can interfere with embryo implantation and are associated with lower pregnancy rates, according to the American College of Obstetricians and Gynecologists (ACOG).
- Intramural Fibroids: These are located within the muscular wall of the uterus. While their impact is debated, large intramural fibroids that distort the cavity or significantly increase uterine volume may reduce IVF success, as noted in guidelines from the European Society of Human Reproduction and Embryology (ESHRE).
- Subserosal Fibroids: These grow on the outer surface of the uterus. These typically do not affect the uterine cavity and generally do not interfere with IVF implantation or pregnancy outcomes.
Diagnostic Evaluation Before IVF
Before beginning an IVF cycle, fertility specialists typically recommend imaging to map the size and location of any existing fibroids. A transvaginal ultrasound is often the first-line diagnostic tool. If the ultrasound suggests cavity involvement, physicians may order a saline infusion sonohysterography (SIS) or a hysteroscopy to provide a clearer view of the uterine lining. These procedures allow the medical team to determine if a fibroid is physically blocking the area where an embryo needs to attach.
Treatment Considerations and Surgical Timing
If a patient has fibroids that are likely to impede pregnancy, doctors may recommend a myomectomy—the surgical removal of the fibroids—prior to starting IVF.
The decision to operate depends on the patient’s specific anatomy and reproductive history. According to the Society for Reproductive Endocrinology and Infertility (SREI), the goal of surgery is to restore normal uterine architecture. However, surgery carries risks, including the formation of intrauterine adhesions or the need for a cesarean section in future pregnancies due to uterine wall scarring. Consequently, patients should discuss the potential benefits and risks with a reproductive endocrinologist to weigh the necessity of surgery against the risks of leaving the fibroids in place.
Clinical Summary
Understanding the relationship between fibroids and IVF is essential for optimizing reproductive outcomes. While many women with fibroids achieve successful pregnancies without intervention, those with cavity-distorting growths may require specialized care.
Frequently Asked Questions
Do all fibroids require surgery before IVF?
No. Most experts only recommend surgical removal for submucosal fibroids that distort the uterine cavity, as these have the strongest evidence for negatively impacting implantation.
Can fibroids grow during pregnancy?
Yes. Because fibroids are sensitive to estrogen, many will increase in size during pregnancy, which can sometimes lead to discomfort or complications.
Does having fibroids automatically mean I need a C-section?
Not necessarily. While large fibroids can sometimes obstruct the birth canal or interfere with labor, many women with fibroids deliver vaginally. Your obstetrician will monitor the size and position of the fibroids throughout your prenatal care.
Related reading