Early fertility and lifetime fertility

Abstract

Teenage mothers are likely to have more children than those who postpone childbearing, but these differences are not as great as they used to be. There is also a pattern of convergence between black women and white women.

PIP: Although women who begin childbearing early bear more children on average than other women, evidence from Cycle II of the 1976 U.S. National Survey of Family Growth shows a tendency for women who began childbearing early to have fewer children in their latter childbearing years than other women, leading to a decline in their excess cumulative fertility. Among recent cohorts of women the turning point age seems to come earlier and the excess in expected completed fertility has declined. This study investigates changes over time in the relationship between ages at first birth and lifetime fertility by studying the average number of children born during 5-year age intervals and calculating expected completed fertility by race and age at 1st birth for 4 5-year birth cohorts of U.S. women born between 1931 and 1950, who had married or had a 1st birth prior to age 25. For white women the turning point has remained constant at age 25 across 4 birth cohorts, while for blacks the difference stabilized at age 30 for the oldest cohort, at 25 for the next, and decreased thereafter. Previous studies may have overstated the excess fertility of teenage mothers by failing to consider their lower fertility in later childbearing years and by not controlling for cohort differences.