1.3 Contribution to total adolescent fertility by age at first birth

Estimating the contribution to total adolescent fertility by age at first birth further spotlights the trends and influence of the youngest adolescent mothers. The measure quantifies the proportional contribution of each age group’s childbearing to total adolescent fertility by allocating all adolescent births (no matter the age at which they occur) into three age categories based on the age of the mother at her first adolescent birth. In West Africa, adolescents with first births at ages 10-14 and 15-17 accounted for two thirds or more of total adolescent fertility (up to 83% in Niger), and more than half of total adolescent fertility was attributable to women with first births specifically at ages 15-17. This measure counters common assumptions about the oldest adolescents driving the bulk of adolescent fertility. The analysis will produce country-specific, regional and global trends.