Endometrial ablation is a procedure that destroys the uterine lining in order to reduce excessive menstrual bloodflow. It is used in cases where hormonal therapy is contraindicated or has not met with success.
Ablation can be performed as surgery under general anesthesia, but is more typically done as a very brief (under ten minutes) outpatient procedure under sedation. The cervix is dilated and instrument(s) inserted to destroy the lining either with cold or heat (e.g., high-frequency radio waves, microwave, heated balloon or heated fluid).
The dilation and instruments used are generally less than 19mm in diameter, and thus do not make a woman niddah simply by opening the uterus. After the procedure, a woman should confirm with her doctor the extent of dilation and the diameter of the instruments that were used.
Bleeding following the procedure, from burning or scarring or trauma from the instruments used, may last for weeks. Halachic authorities debate whether this bleeding may be halachically considered dam makkah, bleeding from trauma. This site follows the position that bleeding from an ablation is in fact considered dam makkah and thus does not make a woman niddah.
Endometrial ablation significantly reduces the chance that a woman will conceive. Any pregnancy following ablation would be high-risk and unlikely to result in a live birth. For this reason, an ablation often effectively sterilizes a woman. (Ablation does not completely prevent pregnancy. Therefore, a woman should discuss her contraceptive needs and options with her physician before the procedure.)
Ablation is generally halachically permissible when medically indicated, especially when a woman is already infertile. Even so, since sterilization of women is generally rabbinically prohibited, a woman should ask a halachic question before undergoing the procedure.
In the long term, a woman who has had an ablation may continue to experience light uterine bleeding from time to time. In these cases, careful adherence to the precautions regarding stains (see our articles on Stains and Toilet Paper), may help her avoid becoming niddah unnecessarily.