Endometrial ablation (EA) is a gynecological procedure designed to manage excessive menstrual blood loss. It involves permanently destroying the endometrium, the tissue that lines the inside of the uterus. EA is typically recommended for women who have completed childbearing and have not found relief from heavy bleeding through medication. While highly effective at reducing or stopping menstrual flow, EA is fundamentally a treatment for bleeding and is not considered a form of birth control. The procedure significantly alters the uterine environment but does not prevent ovulation, meaning pregnancy remains a serious medical concern.
Understanding Conception Rates After Endometrial Ablation
The odds of becoming pregnant after endometrial ablation are significantly lower than for the general population, yet conception remains physically possible. Ablation only affects the uterine lining; the ovaries continue to function normally, releasing an egg each month. Studies suggest the rate of pregnancy following the procedure is low, often falling in the range of 0.24% to 5.2% of women who have the procedure.
This low rate is due to the uterine environment becoming hostile to implantation following the ablation. The destruction of the endometrium and subsequent scar tissue formation mean there is little healthy lining for a fertilized egg to embed into. However, the procedure does not always destroy every endometrial cell, and viable patches of tissue can occasionally remain or regrow. If an embryo manages to find one of these areas, it can successfully implant.
Severe Risks of Pregnancy Following Ablation
If conception occurs after endometrial ablation, the pregnancy carries a substantially increased risk of severe and life-threatening complications. The lack of a healthy, intact endometrium means the fertilized egg may implant in an abnormal location or struggle to establish itself. This hostile environment contributes to high rates of early pregnancy loss, with some reviews indicating that as many as 85% of post-ablation pregnancies end in miscarriage or ectopic pregnancy.
The most significant danger is the risk of abnormal placentation, known as morbidly adherent placenta (MAP), which includes conditions like placenta accreta, increta, and percreta. In a healthy uterus, the placenta attaches to the endometrium, but after ablation, the placenta can invade the scarred uterine muscle wall too deeply due to the absent lining. This complication is extremely dangerous, increasing the risk for severe hemorrhage, hysterectomy at the time of delivery, and maternal death. Women who have had an ablation have been found to be at an approximately 20-fold greater risk for MAP compared to women without the procedure.
Post-ablation pregnancies that continue past the first trimester face higher rates of complications such as preterm delivery, intrauterine growth restriction, and uterine rupture. The overall risk profile for a post-ablation pregnancy is so severe that any pregnancy should be managed as high-risk by medical professionals.
Necessary Contraception Post-Procedure
Given the severe, potentially life-threatening complications associated with pregnancy after endometrial ablation, reliable contraception is necessary. EA is not a sterilization procedure, and relying on the damaged uterine lining alone is insufficient for pregnancy prevention. Patients should be counseled on the need for a highly effective, long-term contraceptive method immediately following the ablation.
The recommended options often include permanent methods that eliminate the risk of user error. Surgical sterilization, such as tubal ligation or tubal occlusion, is one of the most effective ways to prevent future pregnancy. Long-acting reversible contraceptives (LARCs) like hormonal or copper intrauterine devices (IUDs) are also highly effective options.