Humanae vitae raises up the question of planning births in a family. The Church has always taught that it is reasonable for husband and wife to space and even limit births in their marriage for just reasons (see HV, no. 10); however, they are called to support God’s design not to reject it. Use of contraception or sterilization rejects God’s gifts. That is because contraception and sterilization do harm to the nature of married love and the gift of life–they separate the unitive and procreative nature of conjugal relations (see HV, no. 14). Saying this another way, “husband and wife express their committed love not only with words, but with the language of their bodies ….the mutual gift of fertility is an integral part of the bonding power of marital intercourse.” (USCCB, Married Love and the Gift of Life, pp. 4, 5.) To reject one’s fertility by using contraception or being sterilized is to reject God’s gift to husband and wife (see HV, no. 12).