Management of Uterine Fibroids During Pregnancy
Expectant management with close monitoring is the recommended approach for fibroids in pregnancy, as routine myomectomy during pregnancy or at cesarean delivery should be avoided due to the risks outweighing benefits in most cases. 1, 2
General Principles
Most pregnancies with fibroids are uncomplicated, and intervention is rarely needed. 1 However, complications occur in 10-30% of pregnant women with fibroids, particularly when:
- Multiple fibroids are present 1
- Fibroids exceed 5 cm in size 1
- Fibroids are located in the lower uterine segment 1
Surveillance Strategy
Women with fibroids detected in pregnancy require additional maternal and fetal surveillance. 3 Key monitoring points include:
- Red degeneration: The most common complication, occurring in approximately 8% of pregnant women with fibroids 1
- Preterm birth risk: Increased odds ratio of 1.5 (95% CI, 1.3-1.7) 1
- Malpresentation: Increased odds ratio of 2.65 (95% CI, 1.60-3.70) 1
- Placental complications: Including abruption (OR 2.63) and previa (OR 2.21) 1
Surgical Intervention
Cesarean myomectomy should be avoided when possible due to increased risks of hemorrhage and complications. 1 The evidence is clear:
- Current data does not support routine myomectomy during pregnancy or at cesarean birth, as fibroid-related complications are rare and may be outweighed by surgical risks 2
- Cesarean delivery should be performed only for standard obstetric indications, not solely due to fibroid presence 1
- Most women with uterine fibroids can deliver vaginally without complications 1
Exceptions for Surgical Consideration
In highly selected cases, myomectomy during pregnancy may be feasible and safe with good outcomes. 2 The only clear indication for preconception myomectomy is:
- Women who had a previous pregnancy with documented complications specifically related to fibroids 3
Delivery Planning
Vaginal delivery remains the goal for most women with fibroids. 1 Cesarean delivery carries increased risks in this population:
- Cesarean birth odds ratio: 2.60 (95% CI, 2.02-3.18) 1
- Postpartum hemorrhage odds ratio: 2.95 (95% CI, 1.86-4.66) 1
Natural History During Pregnancy
Understanding fibroid behavior during pregnancy helps guide expectations:
- Fibroids significantly increase in size during early pregnancy 2
- Size typically decreases in the third trimester 2
- This natural fluctuation supports conservative management 2
Key Clinical Pitfall
The primary error is performing unnecessary cesarean myomectomy due to fibroid presence alone. The increased vascularity of the gravid uterus substantially elevates bleeding risk during myomectomy, making this intervention dangerous except in rare, carefully selected circumstances. 2