Background: Since they are a healthy and well-nourished isolate with strong religious proscriptions against birth control, the fertility patterns of the Old Order Amish have long been studied by demographers, particularly those with an interest in natural fertility.
Aim: The present report describes population growth, population structure, and fertility patterns in a little-studied Amish settlement located in northeastern Ohio, USA (Geauga Settlement).
Subjects and methods: A directory prepared by the Geauga Settlement provides data on the dates of birth of the mother, father, and all children for 1337 families for the period up to 1 January 1993. This information was used to assess population size, population structure, fertility rates, age at marriage, age of mothers at first and last birth, and birth intervals. Estimates of total settlement size were also derived from an older directory covering the period up to 1 January 1988 and a recently published directory which covers the period up to 1 January 1998.
Results: The settlement consisted of 7546 individuals in 1988, 8345 individuals in 1993, and 9572 individuals in 1998. The completed marital fertility rate was 7.7 (SD 3.6) births per woman. Total fertility rate decreased by about one birth between 1909 and 1967, in association with a change in fertility patterns, with women born in more recent cohorts tending to have more of their offspring at an earlier age, both of which suggest the existence of behaviours to control fertility. On the other hand, the age at the birth of the last child remained fairly constant over this time period.
Conclusions: There is some suggestion of fertility control by Amish families. However, this control appears to be independent of parity, suggesting that there is no intention to limit family size. It is therefore reasonable to conclude that the Amish in the Geauga Settlement are a natural fertility population.