Thanks for explaining,

but I know that heavy periods are not the only medical reason to use the pill.
I am wondering what medical reasons (approved by the church) there could be for direct
sterilization (tubal ligation or vasectomy), situations where not being sterilized would directly bring someone in life danger. (Possible death from pregnancy doesn't count, for the church that is, as abstinence prevents pregnancy too.)
If a woman uses the pill for medical reasons only and she's not sexually active then it's not technically a contraceptive, it functions as medicine. (According to the church it's not a sin to use condoms either, only to use them as contraceptive. It's not a sin to wear them outside a sexual situation.)