The various liturgies abound in prayers of blessing and epiclesis asking God's grace and blessing on the new couple, especially the bride. In the epiclesis of this sacrament the spouses receive the Holy Spirit as the communion of love of Christ and the Church. The Holy Spirit is the seal of their covenant, the ever available source of their love and the strength to renew their fidelity.
Source: Catechism of the Catholic Church (Vatican.va)