How are ectopic pregnancies supposed to be dealt with according to the Catholic Church? The Catholic Church is against abortion in all cases, except, I've heard, where the life of the mother is at serious risk and the child has no chance of survival.  A good example of this would seem to be the case of an ectopic pregnancy, where the human embryo implants in the mothers fallopian tube.  

But some actual forms of abortion would seem to violate respect for the human person, forming in the wrong place by no fault of his or her own.  So, in the end what means are licit for dealing with ectopic pregnancies?
Ectopic pregnancies are a classic application of the principle of double effect:


  The principle that says it is morally allowable to perform an act that has at least two effects, one good and one bad. It may be used under the following conditions:
  
  
  the act to be done must be good in itself or at least morally indifferent; by the act to be done is meant the deed itself taken independently of its consequences;
  the good effect must not be obtained by means of the evil effect; the evil must be only an incidental by-product and not an actual factor in the accomplishment of the good;
  the evil effect must not be intended for itself but only permitted; all bad will must be excluded form the act;
  there must be a proportionately grave reason for permitting the evil effect. At least the good and evil effects should be nearly equivalent.
  All four conditions must be fulfilled. If any one of them is not satisfied, the act is morally wrong.
  
  
  An example of the lawful use of the double effect would be the commander of a submarine in wartime who torpedoes an armed merchant vessel of the enemy, although he foresees that several innocent children on board will be killed. All four required conditions are fulfilled:
  
  
  he intends merely to lessen the power of the enemy by destroying an armed merchant ship. He does not wish to kill the innocent children;
  his action of torpedoing the ship is not evil in itself;
  the evil effect (the death of the children) is not the cause of the good
  effect (the lessening of the enemy's strength);
  there is sufficient
  reason for permitting the evil effect to follow, and this reason is
  administering a damaging blow to those who are unjustly attacking his
  country.
  


See Summa Theologica II-II q. 64 a. 7 or §2.5 "Moral Norms Especially Relevant to Health Care" of Health Care Ethics: A Theological Analysis.

In the case of ectopic pregnancy, neither the death of the child nor of the mother is intended. Curing the ailment may have the unintended side-effect of the death of the child, though, but this does not make curing her morally forbidden.

See:


Fr. T. Lincoln Bouscaren, Ethics of Ectopic Operations, (Milwaukee, Wis.: The Bruce Publishing Company, 1944).
Gerald Kelly, Medico-Moral Problems, 1958.ch. 14 The Morality of Ectopic Operations, p. 105