We exploit a "natural experiment" associated with human reproduction to identify the causal effect of teen childbearing on the socioeconomic attainment of teen mothers. We exploit the fact that some women who become pregnant experience a miscarriage and do not have a live birth. Using miscarriages an instrumental variable, we estimate the effect of teen mothers not delaying their childbearing on their subsequent attainment. We find that many of the negative consequences of teenage childbearing are much smaller than those found in previous studies. For most outcomes, the adverse consequences of early childbearing are short-lived. Finally, for annual hours of work and earnings, we find that a teen mother would have lower levels of each at older ages if they had delayed their childbearing. © 2005 by the Board of Regents of the University of Wisconsin System.