It may pleasantly surprise you that the Catholic Church has a long-standing tradition in support of breastfeeding. The Church, first of all, follows natural law. What could be more natural and in tune with God’s plan for humans than feeding your baby the milk your own body produces? Ecological breastfeeding, too, follows natural law. You follow your baby’s needs for milk and comfort using the body God gave you as a gift. You are then a gift to your child. The infertility that results is nature’s design and another gift to you.
As I write this, there is a heated debate taking place on a popular Catholic internet site. They are discussing whether or not breastfeeding can be done in a selfish manner due to its natural benefit of infertility. My personal opinion is “no.” You can’t force your baby to nurse if he doesn’t want to. Even if you wake him in the middle of the night to nurse in the hopes of extending your own natural infertility, he will only nurse if he needs it. On a personal note, I have bedshared with all my children, and they woke naturally one to several times per night until around age two without any help from me. Also, in the over ten years I have been involved with supporting nursing mothers, no one has mentioned that they wake their baby to nurse during the night (except for maybe a sleepy newborn baby in the first week of life)! On the contrary, moms usually accept this phase of life and all it entails or try different techniques to get their babies to sleep through the night. Then there is also the situation of many women who would love to have another baby but are unable to conceive because they are breastfeeding.
In terms of support from popes and bishops, Pope Gregory the Great, Pope Benedict XIV, Pope Pius XII, and (Saint) Pope John Paul II all showed support of breastfeeding. The two latter popes publicly spoke to mothers about its importance (Breastfeeding and Catholic Motherhood, p. 32-34). The current pope, Pope Francis, has been especially supportive of breastfeeding moms. On Holy Thursday, he washed the feet of twelve pregnant and nursing moms - one mom was actively nursing her baby during the actual washing of feet! On another occasion, he encouraged mothers to nurse their hungry babies during a baptism ceremony in the Sistine Chapel. At least two bishops also advocated for breastfeeding - Bishop James T. McHugh and Alfonso Cardinal Lopez Trujillo. (Breastfeeding and Catholic Motherhood, p.36-37). As you can see, the Magisterium wholeheartedly supports nursing moms and babies.
Several priests actively promote breastfeeding in their own unique ways. Father Virtue wrote a chapter on breastfeeding in his doctoral dissertation, Mother and Infant. Father Timothy Sauppe created a Madonna chapel and developed a rosary of five mysteries in honor of Mary’s breastfeeding relationship with Jesus which was granted an imprimatur (Breastfeeding and Catholic Motherhood, p. 38-40). I am sure there are countless other Church leaders who are doing a wonderful job supporting nursing mothers.
Christian artwork often portrays Mary breastfeeding Jesus, sometimes with her breast exposed. Scripture mentions breastfeeding no less than 12 times, and weaning is often mentioned as taking place at the end of the second or third year of life.
The Catholic Church honors two souls in heaven as patron saints of breastfeeding. St. Giles is one of the official patron saints of breastfeeding mothers. He was a hermit in Southern France in the late 600s - early 700s who reportedly sustained himself for several years only on the milk of a hind. His feast day is September 1. In addition, the diocese of St. Augustine, FL celebrates the feast of Our Lady of La Leche on Oct. 11. Our Lady of La Leche is the patron saint of nursing mothers and women who want to become pregnant. There is a shrine in the city of St. Augustine dedicated to Mary in this role. Breastfeeding is so important, it has two patron saints, including the Blessed Mother!
(excerpt from book, Getting Started with Breastfeeding: For Catholic Mothers by Gina Peterson)
NFP International has some great links to what different popes have said about breastfeeding.
Also, here is a link to a story about Pope Francis encouraging mothers to nurse their babies in the Sistine Chapel.