The impact of the timing, spacing, and number of children on a married woman's wage growth over her life cycle was examined. The data used for the analysis were information pertaining to the labor market experience of women and the birth dates of their children, taken from the 1976 survey of the Michigan Panel Study of Income Dynamics (IDP). There were four principal findings. First, the number of children a woman rears has an important deterrent effect on her accumulated work experience. A woman who has one child will average about 2.5 years less work experience over her lifetime than a woman with no children. A second child results in an additional two years withdrawn from the labor market. Second, larger birth intervals (holding constant the number and timing of children) are associated with larger reductions in lifetime work effort. The magnitude of this effect appears to increase with the number of children. Third, the timing of the first birth (the age at which a woman has her first child) does not appreciably affect lifetime labor market experience. Fourth, child rearing, through its effect on accumulated work experience, has a substantial effect on wage rates. (EM)