What is the recommended management approach for a pregnant woman with uterine fibroids?

Management of Uterine Fibroids in Pregnancy

Pregnant women with uterine fibroids should be managed expectantly with close surveillance and supportive care, as most fibroids remain stable or only minimally change in size during pregnancy, and the majority of pregnancies proceed successfully without intervention. 1, 2

Core Management Principles

Expectant Management is Standard of Care

• Conservative management with regular monitoring is the recommended approach for pregnant women with fibroids, as pregnancy has little to no effect on overall fibroid size despite occasional red degeneration in early pregnancy. 1

• Most fibroids in pregnancy are asymptomatic, but when complications occur, they typically include abdominal pain, threatened miscarriage, preterm labor, malpresentation, and difficult delivery. 1, 2

• The size, location, number of fibroids, and their relationship to the placenta are the critical factors determining pregnancy outcomes and complications. 1

Surveillance Protocol

• Ultrasound scanning is the central diagnostic and monitoring tool throughout pregnancy, used to track fibroid size, detect heterogeneous echo patterns associated with pain (suggesting degeneration), and determine the position of fibroids relative to the placenta. 1

• Color flow Doppler scanning should be used to differentiate true fibroids from myometrial thickening that may be mistaken for fibroids. 1

• Regular antenatal follow-up with careful screening is essential to detect adverse obstetric complications early and improve outcomes. 2

Common Complications and Their Management

Pain Management

• Abdominal pain is one of the most frequent complications, often related to red degeneration occurring in early pregnancy. 1, 2

• Conservative pain management with analgesics and supportive care is typically sufficient for pain episodes. 2

• In rare cases requiring hospitalization for severe pain, admission for observation and symptomatic treatment may be necessary (approximately 4% of cases required admission in recent studies). 2

Obstetric Complications

• Threatened miscarriage occurs in approximately 34% of pregnant women with fibroids, requiring close monitoring and standard threatened miscarriage protocols. 2

• Preterm labor affects approximately 21-28% of pregnancies with fibroids, necessitating standard preterm labor management including tocolytics when appropriate. 2

• Malpresentation and difficult delivery are common, with cesarean section rates reaching 85% in women with significant fibroids. 2

• Postpartum hemorrhage occurs in approximately 4% of cases and should be anticipated with appropriate preparation for active management of the third stage. 2

Contraindicated Interventions During Pregnancy

Medical Therapy is Not Appropriate

• All medical therapies used for non-pregnant fibroid management—including GnRH agonists, GnRH antagonists, selective progesterone receptor modulators, combined oral contraceptives, and levonorgestrel IUDs—are contraindicated during pregnancy. 3, 4, 5

• These medications suppress fertility during treatment and have unknown or potentially harmful effects on pregnancy outcomes. 6, 4

Surgical Intervention is Rarely Indicated

• Myomectomy during pregnancy is only performed in carefully selected patients with severe complications, as it carries significant risk of jeopardizing pregnancy outcome. 1

• The vast majority of pregnant women with fibroids should not undergo surgical intervention during pregnancy, even when fibroids are large or multiple. 1, 2

• Surgical management should be deferred until after delivery in nearly all cases. 1

Prognostic Factors

Reassuring Evidence

• The obstetric outcomes are not significantly affected by the number, size, or type of fibroids (intramural versus subserosal), with most pregnancies achieving acceptable outcomes. 2

• Neonatal outcomes are generally favorable with no significant increase in perinatal mortality when appropriate surveillance is maintained. 2

• Successful pregnancy and delivery is common with appropriate surveillance and supportive management. 1

Risk Stratification

• Women with fibroids >2 cm require closer monitoring throughout pregnancy for potential complications. 2

• The relationship of fibroids to the placental site is particularly important for predicting complications such as placenta previa (occurring in approximately 2% of cases). 2

Delivery Planning

• Cesarean delivery should be anticipated and planned for women with large fibroids, multiple fibroids, or fibroids in locations that may obstruct labor, with cesarean rates reaching 85% in affected pregnancies. 2

• The mode of delivery decision should be based on fibroid location relative to the cervix and lower uterine segment, fetal presentation, and standard obstetric indications. 2

• Only 15% of women with significant fibroids achieve vaginal delivery, so cesarean preparation is prudent. 2

Critical Pitfalls to Avoid

• Do not attempt medical management with hormonal therapies or GnRH modulators during pregnancy—these are contraindicated and potentially harmful. 6, 4

• Do not perform routine myomectomy during pregnancy; reserve surgical intervention only for rare, severe complications that cannot be managed conservatively. 1

• Do not assume rapid fibroid growth during pregnancy indicates malignant transformation—sarcomatous change is extremely rare and pregnancy-related growth is typically benign. 7

• Do not neglect iron supplementation if anemia develops from bleeding complications, as this is a manageable aspect of care. 3