"A Child does not come from outside as something added on to the mutual love of the spouses, but springs from the very heart of that mutual giving, as its fruit and fulfillment. So the Church, which is 'on the side of life' teaches that 'it is necessary that each and every marriage act remain ordered per se to the procreation of human life' " (Catechism of the Catholic Church, no. 2366, citing Familiaris Consortio, no. 30 and Humanae Vitae, no. 1, respectively).

Contemporary methods of natural family planning are making it possible for couples, in cases of legitimate need, to space the births of their children while remaining faithful to God's plan for marriage. These methods allow a couple to have a more precise knowledge of the time of ovulation to enable them to either avoid or achieve a pregnancy. "The regulation of births represents one of the aspects of responsible fatherhood and motherhood. Legitimate intentions on the part of the spouces do not justify recourse to morally unacceptable means (for example, direct sterilization or contraception)" (Catechism of the Catholic Church no. 2399).

Both of these paragraphs were cited from the United States Catholic Catechism for adults page 409