Much of what the Catholic Church teaches about respect for human life and the dignity of procreation is found in Donum Vitae ("The Gift of Life"), a 1987 statement from the Vatican Congregation for the Doctrine of the Faith that was approved by Pope John Paul II. The document should be read in its entirety, but here are two key paragraphs:
"In reality, the origin of a human person is the result of an act of giving. The one conceived must be the fruit of his parents' love. He cannot be desired or conceived as the product of an intervention of medical or biological techniques; that would be equivalent to reducing him to an object of scientific technology. No one may subject the coming of a child into the world to conditions of technical efficiency which are to be evaluated according to standards of control and dominion.
"The moral relevance of the link between the meanings of the conjugal act and between the goods of marriage, as well as the unity of the human being and the dignity of his origin, demand that the procreation of a human person be brought about as the fruit of the conjugal act specific to the love between spouses."
Thus, the Church does not approve of in-vitro fertilization or artificial insemination, even when the sperm and ova are those of the married couple.
However, the Church does approve of treatments that assist in achieving conception in normal intercourse. These would include:
Training in determining and taking advantage of high fertility days (natural family planning).
Moral medical testing of both spouses to determine their overall health and any abnormalities in their reproductive organs.
Medication to provide more normal functioning of the reproductive system, such as improving ovulation or the quality of sperm.
Surgery to enable normal functioning of the reproductive system, such as removing obstructions from the fallopian tubes or reversing a vasectomy.
Low tubal ovum transfer (LTOT). If a fallopian tube is blocked or damaged, the ovum may be transferred past the blockage and into the lower part of the tube.
Theologians disagree over the morality of some other treatments about which the Church has not yet spoken.
One of these disputed techniques is gamete intrafallopian transfer (GIFT), in which an ovum from the wife is separated by an air bubble in a tube from semen of the husband that has been gathered after intercourse, and both are placed in the woman's fallopian tube for conception to take place within her body.
Since there is theological disagreement over the morality of GIFT, some bishops do not permit GIFT in Catholic health institutions in their dioceses.
For further discussion about the morality of various infertility treatments, see the comments of the U.S. Conference of Catholic Bishops at www.osv.com/ morereading.