Fertility and the Stability of Cohabiting Unions: Variation by Intendedness.

An extensive body of research demonstrates that children increase the stability of marriage. However, it is not clear whether the theories explaining greater marital stability among parents can be applied to the increasing number of cohabiting couples who have children, as cohabitation plays more varied roles in the family system than marriage. Furthermore, theories about children and marital stability often assume that births are intended, which is less likely to be the case for cohabiting than for marital births. Using data from the 2002 cycle of the National Survey of Family Growth, we find that intended and disagreed-upon pregnancies (but not unintended pregnancies) reduce the risk of dissolution relative to women who have no pregnancy or birth. Relative to non-fertile couples, all pregnancies increase the risk of marriage over staying cohabiting, but couples with a birth show little difference in the odds of stability or transitions once the child is born. However, relative to an intended birth, having an unintended or disagreed-upon birth increases the risk of dissolution. These findings suggest that normative pressures influence the union behaviors of cohabitors during pregnancy, while selection processes and rational choice considerations play a greater role after a birth.