Reproductive span and rate of reproduction among Hutterite women.
As studies of procreative capacity in the human female are seriously limited by the fact that it is difficult to find sizable populations for which accurate data can be obtained and which do not practice contraception, it is fortunate that a substantial body of new data has become available concerning a contemporary American community--the Hutterites--who do not practice any form of birth control. A Protestant sect, the Hutterites live in the Dakotas, Montana, and the adjacent portions of Canada in small agricultural settlements they term colonies. The sect had its origin in Switzerland in 1528, but ancestors of the American Hutterites came to this continent in the 1870s. Not only is the practice of contraception condemned by Hutterite religion and folkways, but the communal structure of the settlements removes any economic incentive to family limitation. The birthrate of the Hutterites is one of the highest on record. The death rate corresponds to that of the general population of the US. This report is based on the histories of 209 Hutterite women who married prior to age 25, married only once, and who were living with their husbands at age 45. 3 out of 4 women in this group, 151, were observed in the married state up to or beyond the age of 50 years. The remaining 58 were observed to some point between 45-50 years. Of the 209 women in the study, 5 had no children. The remaining 204 women had experienced from 2-16 pregnancies excluding those terminating in fetal death. The total number of confinements was 2009. These 2009 pregnancies resulted in 1989 single births and 20 pairs of twins. About 1 woman in 10 had ceased to produce--and presumably had become unable to reproduce, by age 35, 1 in 3 by age 40, and 7 of 8 by age 45. The average age at 1st confinement for the 204 mothers was 22.2 years, and the average age at last confinement, as observed, was 40.9 years. The average time elapsed between the 1st and last confinement was 18.7 years, and the average number of intervals between confinements was 8.8, 1 less than the number of confinements per mother. From these data a mean interval of 25.5 months can be computed. With average ages of 20.7 years at marriage and 22.2 years at 1st confinement, the interval between these 2 events can be estimated to be about 18 months, and the interval between marriage and 1st conception about 7 months. The average interval between confinements varied only slightly among 4 groups of mothers, ranging from those who had their last confinement prior to age 35 to those who gave birth after age 45. This insignificant difference suggests that among the Hutterites early cessation of reproduction was generally not caused by constitutional factors but by adventitious factors so far not identified.