confounding factors that are both a cause and consequence of early childbearing, it is not possible to assess the short-term and long-term effects of adolescent childbearing.

Although parenthood continues to occur largely within a socially recognized union (typically marriage) regardless of age, most literature about first parenthood focuses on premarital childbearing, with a particular focus on adolescents (a topic we will return to). However, given that marital childbearing remains the most typical pattern (Mensch, Bruce, and Greene, 1998), we start this discussion of sequencing of parenthood within marriage by considering the timing of first birth within marriage.

First to set the context, however, we explore trends in the proportion of births that occur after union formation or marriage (Table 8-5).⁵ For this analysis, we do not distinguish between premarital and postmarital conceptions, because we are interested in the social context in which the birth occurs, not the social context in which the conception occurs. Overall, among 20-24-year-olds, 91 percent of young women have their first birth after marriage. The decline has been very slight in the last 20 years. Patterns vary substantially by region, however, as do trends. For those countries in the Middle East and Asia, where data were collected only on married women, we have to assume that unmarried women have not given birth; thus any premarital births that are captured in the data are those reported by women who are currently married. The proportion of births that occur within marriage varies from a low of 70 percent in Eastern and Southern Africa and 74 percent in South America to highs of 97 percent in Southern Asia and close to 100 percent in the Middle East. There is also an inverse correlation between a country’s level of income and the proportion of births that occur within marriage.

Premarital births represent a rising proportion of births in Eastern and Southern Africa, South America, and in upper middle-income countries (Table 8-5). There was much greater homogeneity across regions 20 years ago than there is today in the proportion of births that occur within marriage. A discussion of trends in the percentage of young women having a birth premartially and the implications of out-of-wedlock motherhood fol-