XII. 3. Among the problems which need a religious and moral assessment is that of contraception. Some contraceptives have an abortive effect, interrupting artificially the life of the embryo on the very first stages of his life. Therefore, the same judgements are applicable to the use of them as to abortion. But other means, which do not involve interrupting an already conceived life, cannot be equated with abortion in the least. In defining their attitude to the non-abortive contraceptives, Christian spouses should remember that human reproduction is one of the principal purposes of the divinely established marital union (see, X. 4). The deliberate refusal of childbirth on egoistic grounds devalues marriage and is a definite sin.