Age and infertility in a micronesian atoll population

The relationship between female age and infertility is examined using a single-island Micronesian population case. Demographic data, derived primarily from reproductive history interviews, show that a significant age-associated decline in marital reproductive performance is absent before women reach their late thirties in this population but a substantial decline is present once women reach their forties. Ethnographic data support the demographic inference that couples are maintaining relatively high levels of conjugal coital activity with both advancing female age and increasing marital duration. Thus coital activity levels appear to be an important factor in the maintenance of fertility in this group before the mid-thirties but decreases in fecundability after this age are due primarily to reductions in fecundity, not to declines in coital activity. The description of the Butaritari case lends support to Underwood's (1990) suggestion that a "Micronesian pattern" of reproductive performance may exist for the region's atoll-based populations and underscores the promise of further investigations of these special cases in the fields of demography and reproductive ecology.