Moral actions that produce two effects need to be evaluated under the Catholic understanding of the principle of double effect:
- The action must be either morally good or neutral.
- The bad effect must not be the means by which the good effect is achieved.
- The intention must be the achieving of only the good effect; the bad effect can in no way be intended and must be avoided if possible.
- The good effect must be at least equivalent in proportion to the bad effect.
An ectopic pregnancy occurs when the fertilized ovum implants in the fallopian tube or in some other location. A mother facing a tubal pregnancy risks imminent rupture of the fallopian tube, and thus, there exists a danger to the lives of both the mother and the child.
Removing the fallopian tube is considered in accordance with the principle of double effect:
- Removing a part of the body that is about to rupture and cause the death of the individual is a morally good action.
- The death of the child is not the direct intention of the procedure. It is the removal of the fallopian tube that saves the life of the mother, not causes the death of the child.
- The death of the child is not willed and would be avoided if at all possible—if, for example, re-implantation in the womb were reasonably possible.
- The life of the mother is, of course, equal to the life of the child.