description): The transformation in family life in recent decades has included changes in the timing and in the occurrence of key family building events. These shifts include substantial delays in the timing of first births after marriage, and increasing intervals between births. Because most research examining the timing of family building events has focused on the transition to a first family building event (e.g., marriage, cohabitation, or a nonmarital birth), the shift toward longer birth intervals is not well understood. A handful of studies has linked birth intervals to women's labor force participation, but two competing hypotheses have been put forward: the desire to work shortens birth intervals to hasten the end of childbearing and the desire to work lengthen birth intervals to reduce the severity of work interruptions. The research proposed here is designed to sharpen our understanding of the processes that affect the timing of births compared with other events in the life course by focusing on the intersection of work-family roles and demands. Using data from the multiple waves of the National Longitudinal Survey of Youth in event historical models of interval duration, the applicant proposes to: 1) determine how time-varying employment circumstances and histories of wives and their husbands relate to the transition to a first birth after marriage and the timing of a second birth after a first birth; 2) determine how employment relations surrounding the first birth--including the timing of prenatal job exits and postnatal employment returns, and the availability and nature of maternal/paternal leave--relate to the transition to second birth; and 3) determine how pre- and perinatal experiences surrounding the first birth--including the desire of the birth, traumatic birth experiences, and breast feeding--affect the timing of a second birth, with a particular focus on how these factors may interact with employment.