Multipartner Fertility in Nicaragua: Complex Family Formation in a Low-Income Setting.

Context: Multipartner fertility (having children with more than one partner) is an important topic in demographic research, but little is known about its incidence and correlates in low-income settings, where rates may be high because of poverty, union instability and early childbearing.

Methods: Data from the 2011-2012 Encuesta Nicaragüense de Demografía y Salud were used to calculate the prevalence of multipartner fertility among 8,320 mothers and 2,141 fathers with two or more children. Logistic and multinomial regression were used to identify individual and family characteristics associated with multipartner fertility.

Results: Among those with multiple children, 33% of mothers and 41% of fathers had had children with more than one partner. The prevalence of multipartner fertility was elevated among less-educated women, nonreligious men, and women and men who had grown up in urban areas (odds ratios, 1.3-1.6). Multipartner fertility was associated with lower current household wealth among mothers, and with increased risk of single parenthood and higher fertility among mothers and fathers. Fathers who had had multiple fertility partners were six times as likely as fathers with one fertility partner to report not providing financial support to, or sharing their surname with, at least one of their biological children.

Conclusion: Multipartner fertility is a critical demographic and social phenomenon that may contribute to and reflect important gender and family structure inequalities in Nicaragua. Mothers with multipartner fertility may be at especially high risk of raising children without the children's fathers and with low levels of economic support.