ABSTRACT
The statistical study of human fertility is particularly complex because of the large number of quantitative factors that can be included a priori to describe it and to analyze its variations. This chapter examines the fertility rates by age, essentially the age-specific fertility rates and the marital fertility rates. In the analysis of fertility, the general fertility rate is the first refinement in rates in measuring natality. An improvement in the description of the fertility of populations can be anticipated when the study of cumulative fertility is connected to the event that most often marks its beginning—marriage. The relationship between fertility and duration of marriage is particularly close among couples practicing contraception, since they seek to become infertile when the desired family size is attained. The study of protogenetic intervals yields proof of the lower fertility of the youngest women.
