Transitions between childlessness and first birth: three generations of U.S. women.

Objective: This report analyzes the patterns of childlessness, and conversely, the first-birth patterns of three birth cohorts of American women. For this report, a cohort refers to women born in the same year. The cohorts compared were women born in 1910, 1935, and 1960-who, consequently, turned 25 during the Great Depression, the Baby Boom, and lastly, the post-Baby Boom period. The purpose of the report is to explore the differences in fertility characteristics of these three generations of women and to consider those differences in light of the social and economic conditions at the time.

Methods: Life table methodology, including the probability of having a first birth, the number of women remaining childless, and the expected number of years to remain childless, was applied to each of the three birth cohorts for comparison. Techniques extended from life table functions were also used and included measures of first-birth concentration as well as comparisons between childlessness and the total fertility rate (TFR). Data were based on the Centers for Disease Control and Prevention's National Center for Health Statistics tables on cohort fertility.

Results: Of the three birth cohorts studied, the women born in 1910 had the highest proportion childless and a low TFR. In contrast, the women born in 1935 had both the lowest proportion childless and the highest TFR. The fertility of women who were born in 1960 is characterized as intermediate to the other cohorts in terms of childlessness, but is distinct with both lowest levels of childbearing and oldest ages of first births. First-time childbearing is more concentrated (that is, least spread out) by age of mother for the 1910 and 1935 cohorts than the 1960 cohort. Finally, data for all U.S. birth cohorts 1910-1960 suggest that the greater the proportion childless in a cohort; the lower the TFR.