What is the ruling in Islamic law for tubal ligation? Please note that my wife cannot use any kind of contraceptive because she suffers from diabetes and a uterine tumor. Her attending physician says that it is necessary for her to have tubal ligation. Moreover, pregnancy is dangerous in her case.
Tubal ligation which terminates the potential to procreate is prohibited except when necessary. This is because it terminates procreation, undermining the need to protect lineage which is one of the five necessities that Islam has made among the objectives of its laws.
Tubal ligation is permissible when necessity, such as when a trustworthy specialist determines that a future pregnancy puts the mother's life at risk or if there is a genetic disorder that can be passed on to the fetus. A woman does not sin and is not blameworthy for undergoing permanent sterilization if her physician determines that this is the only solution to avoid imminent harm.
It is permissible for the inquirer's wife who suffers from the medical conditions mentioned in the question to undergo tubal ligation by a specialist.
Allah the Almighty knows best.