Stepfamily fertility in contemporary Sweden: The impact of childbearing before the current union.

We focus on the fertility of Swedish men and women who lived in a consensual or marital union in the 1970s and 1980s, and where at least one of the partners had children before they entered that union. Couples without any children before the current union were included for contrast. We find clear evidence that couples wanted a shared biological child, essentially regardless of how many children (if any) they had before their current union. The shared child seems to have served to demonstrate commitment to the union, as did its conversion into a formal marriage. We have not found much support for the hypothesis that our respondents sought to enter parenthood to attain adult status. A second birth might have been valued because it provided a sibling for the first child -- a half-sibling acting as a substitute for a full sibling -- but our evidence for such effects is contradictory. Our analysis makes it very clear that parity progression depends on whose parity we consider. [ABSTRACT FROM AUTHOR]