Pope Pius XII
Mystici Corporis Christi §99
Mystici Corporis Christi: On the Mystical Body of Christ
99 In this connection We cannot pass over in silence the fathers and mothers of families to whom our Savior has entrusted the youngest members of His Mystical Body. We plead with them most earnestly, for the love of Christ and the Church, to take the greatest possible care of the children confided to them, and to protect them from the snares of every kind into which they can be lured so easily today.
Source: Mystici Corporis Christi (Vatican.va)