Does partner change between pregnancies moderate the association between preferred and actual IBI?

Abstract

Several previous studies have showed that, compared to staying with one partner, changing partner increases IBIs. In the current study we investigated whether — partner change moderates the association between preferred and actual IBI. More specifically, we investigated: 1) whether the preferred length of IBI before having children is associated with the actual length of IBI and; 2) whether this association is weaker in women who change partner (i.e., a new father for their second child). We recruited 703 mothers between the ages of 18 and 60 with at least two biological children (excluding twins). The average length for preferred IBI was 32.71 months and 39.99 months for the actual IBI. The association between the preferred and actual IBI due to partner change was weaker for those females who change the partners and the actual IBI was also longer in these individuals. The actual IBI tended to increase by 4.36 months on average for each new year of the preferred IBI if a female did not change partners. However, if the partner changed, the actual IBI was increased by 9.76 months for each additional year of the preferred IBI. Keeping a steady partner, females are more likely to have less time between birth of second child and to better match actual IBI to the preferred IBI.