Age and infertility: An ethnodemographic study from Butaritari Atoll, Kiribati.

Abstract

This biocultural study examines patterns of infertility, or failure to produce live births, by female age cohorts in the Micronesian population of Butaritari Atoll, Kiribati. Anthropological and demographic methods employed included analysis of census survey, reproductive history collection, structured and semi-structured interviews, participant observation, ethnohistorical research, vital registrations, and clinic records. Primary infertility levels are found to be extremely low in this population. This is argued to be a consequence of low risk of exposure to fertility-inhibiting disease, typically extended exposures to coital activity, and a culturally-influenced resistance to birth-limiting behavior before at least one child is born. There is little reduction in fertility, and therefore in biological capacity for conception, before women reach the end of their thirties. This pattern of high fertility is maintained because of socio-culturally defined patterns of sexual behavior within marriage which tend to maintain coital activity despite increasing marriage durations, and therefore with increasing age. In the study's conclusion infertility patterns by age for this population are discussed in relation to issues of the role of physiological aging and infertility increases in human populations. It is concluded that studies of infertility by age need to be considered as culturally-grounded and population-specific, particularly in reference to patterns observed at the population level in female age groups under forty.