The wedding cake is actually a fertility cake, as large, sweet cakes have long been associated with fertility in the Christian tradition.
St. Rita of Cascia is the patron saint to pray to if you desire children. She was a 15th-century Italian woman whose husband (via an arranged marriage) was physically abusive and unfaithful. However, she bore him two sons, and after 20 years of her praying for her husband to reform, he did--just before he died from a knife wound he received in a fight.
Talk to your priest about receiving the new Catholic blessing for pregnant women. Some churches perform the blessing individually, others with a group of expectant mothers at Mass.
Begin thinking about choosing godparents for your baby. For baptism, your child will need to have at least one sponsor who is an active Catholic. The church will allow a baptized Christian who is not Catholic to serve as a second godparent.
Pregnant women have several patron saints in the Catholic tradition, including St. Elizabeth and St. Gerard Majella. He was falsely accused by a pregnant woman of being the father of her child. She later recanted and cleared him, and St. Gerard became associated with all aspects of pregnancy. Devotions to Mary, the mother of Jesus, are also common during pregnancy.
Pray to St. Anne, grandmother of Jesus and mother of Mary, the patron saint of women in labor. St. Raymond Nonnatus, born in 1204 and delivered by Cesarean section, also became a patron saint of childbirth.
Baptism is the rite of welcome, celebration, and initiation for Catholic infants. Catholics believe that in baptism, babies are reborn through water and the Holy Spirit, and are cleansed of original sin. In passing through the water, Catholics believe, the baptized person shares in Jesus' death and resurrection. The sacrament is usually performed at Sunday Mass in the local parish church where the parents are members.