Relationship dynamics and pregnancy: seriousness, instability, and partner change

Jennifer S. Barber, University of Michigan
Yasamin Kusunoki, University of Michigan
Heather H. Gatny, University of Michigan
Jennifer Yarger, University of California, San Francisco

This paper uses data from the Relationship Dynamics and Social Life (RDSL) project. Using longitudinal data from a weekly survey of 1,000 young women spanning 2.5 years (130 weeks), we examine the types of relationships that lead to pregnancy. We focus on the dynamics of these relationships, specifically examining three dimensions (time spent together, commitment, and cohabitation) during four time periods (current week, past month, entire history with current partner, and history with prior partners). Time-intensive and/or committed weeks, months, and relationships are associated with a higher pregnancy rate than other weeks, months, and relationships. In addition, having a history of committed and/or cohabiting relationships with prior partners is associated with pregnancy, net of the current relationship's character. The first week with a new partner (but not getting back together with a prior partner) is associated with over three times higher odds of pregnancy. Further, changes in seriousness (i.e., instability) increase pregnancy risk. For example, the first week a respondent considers her relationship "committed" is associated with nearly four times higher odds of pregnancy than relationship weeks that remain "uncommitted." Finally, a history of instability in terms of cohabitation – moving in and out with prior partners – is associated with an increased risk of pregnancy. Overall, our analyses suggest that understanding both seriousness and instability, and particularly the ways they operate independently and in tandem, are important pieces of the puzzle of early pregnancy.