Determinants of protogenetic interval in a west Mediterranean rural population: La Alpujarra (southeast Spain).

This paper analyzes the protogenetic interval determinants and the influence on family size. The data came from La Alpujarra (Southeast Spain), consisting on a sample of 847 families marrying through-out the first half of the present century. The marital fertility includes 85% deliveries, 5% premarital births and the remaining 10% premarital conceptions. The protogenetic interval was clearly associated with the reproductive success since family size was nearly one child greater for short intervals (= < 16 months). The protogenetic interval largely depends on the occurrence of miscarriages preceding the first liveborn delivery as well as on maternal age. Consanguineous couples show slightly shorter intervals. A temporal decrease of protogenetic intervals was observed.