Letter from the First Presidency, April 14, 1969: ((Realities of the Population Explosion, May 1971 Ensign – https://www.lds.org/ensign/1971/05/realities-of-the-population-explosion?lang=eng)

“Presidents of Stakes, Bishops of Wards, and Presidents of Missions
Dear Brethren:

The First Presidency is being asked from time to time as to what the attitude of the Church is regarding birth control. In order that you may be informed on this subject and that you may be prepared to convey the proper information to the members of the Church under your jurisdiction, we have decided to give you the following statement:

We seriously should regret that there should exist a sentiment or feeling among any members of the Church to curtail the birth of their children. We have been commanded to multiply and replenish the earth that we may have joy and rejoicing in our posterity.

Where husband and wife enjoy health and vigor and are free from impurities that would be entailed upon their posterity, it is contrary to the teachings of the Church artificially to curtail or prevent the birth of children. We believe that those who practice birth control will reap disappointment by and by.

However, we feel that men must be considerate of their wives who bear the greater responsibility not only of bearing children, but of caring for them through childhood. To this end the mother’s health and strength should be conserved and the husband’s consideration for his wife is his first duty, and self control a dominant factor in all their relationships.
It is our further feeling that married couples should seek inspiration and wisdom from the Lord that they may exercise discretion in solving their marital problems, and that they may be permitted to rear their children in accordance with the teachings of the gospel.”

David O. McKay, Hugh B. Brown, N. Eldon Tanner