In 1954, Joseph W. Eaton and Albert J. Meyer published their landmark study on Hutterite fertility. They documented that from 1880 to 1950, the Hutterites grew from 443 to 8,542 persons. This represents an annual increase of 4.12 percent, which appears to be the world's fastest natural growth rate. Documenting an average family size of slightly over ten children, Eaton and Meyer established the Hutterites as the demographic standard and estimated that maximum fertility for humans is twelve to fourteen children.
Because Hutterites do not marry when a woman first becomes fertile and because there is virtually no premarital sex, the actual number of children is lower than the theoretical maximum. Birth control is considered to be murder, and Eaton and Meyer noted that it was often not used when medically recommended. Natural methods, such as coitus interruptus, are considered sinful. These sexual beliefs and practices have been substantiated in other research (Lee and Brattrud 1967).
Since that time a 33-percent drop in their birthrate has been confirmed. K. Peter (1966, 1980) attributed the decline to later age of marriage and speculated that the purpose was to delay colony divisions or to save money and avoid having idle workers. Although it is true (Laing 1980) that age of marriage is increasing and colony size decreasing, others (Boldt and Roberts 1980) believe that some forms of birth control must be practiced, which could represent a weakening of church authority and a change in core values.
In 1985 access was given to the medical records of all Hutterites treated at a clinic in a small southern Alberta town. Six colonies (three Lehrerleut and three Dariusleut) patronize that clinic for treatment. The clinic had medical records on forty-eight married Hutterite women. Of these 12.5 percent of the women had used oral contraceptives, IUDs, or both. An additional 25 percent had tubal ligations or hysterectomies, meaning that over one-third of the sample made use of some form of birth control. Other physicians and Hutterite leaders confirmed this (Ingoldsby and Stanton 1988).