Handling Statements on Contraception
One of the toughest issues to address with engaged couples (if not the toughest) is contraception. Not only is it a topic which includes decisions on intimacy in a couple's life, but is the least understood teaching of the Church.
While contraception seems like it is only a single issue, it spills out into so much more. When couple's make the decision to contracept prior to marriage, it sets up other important choices on premarital sex, the gift of new life, whether or not to cohabitate and how they view the teachings of the Church. If they can side-step this one area, doesn't that make it easier to turn their back on more?
Our role is vital in this discussion, so we need to be knowledgeable so we can address the engaged couples questions in a straight-forward, compelling, and engaging way. Listed below are some good resources you may wish to give the couple as homework prior to your discussion.
Couple's Workbook

Page 18 in the Intimacy Section:  
“CONTRACEPTION: A crucial aspect of a married couple’s sexual relationship is their openness to new life, the procreative dimension of intercourse. If we agree that sexual intercourse is the complete and total sharing of two people, then this implies that they share their bodies, minds, souls, and futures. The Church teaches, then, that every act of sexual intercourse should remain open to the transmission of new life, with the use of contraception in serious error. (Humanae vitae, no. 12)”
Church's documents:
“When married couples deliberately act to suppress fertility, however, sexual intercourse is no longer fully marital intercourse. It is something less powerful and intimate, something more ‘casual.’ Suppressing fertility by using contraception denies part of the inherent meaning of married sexuality and does harm to the couple’s unity. The total giving of oneself, body and soul, to one’s beloved is no time to say: ‘I give you everything I am—except …’ The Church’s teaching is not only about observing a rule, but about preserving that total, mutual gift of two persons in its integrity.
 
“This may seem a hard saying. Certainly it is a teaching that many couples today, through no fault of their own, have not heard (or not heard in a way they could appreciate and understand). But as many couples who have turned away from contraception tell us, living this teaching can contribute to the honesty, openness, and intimacy of marriage and help make couples truly fulfilled.” (Married Love and the Gift of Life issued by the USCCB November 14, 2006.)

Click here for full brochure"Married Love and the Gift of Life" USCCB 2006