Stepfamily childbearing in Sweden: quantum and tempo effects, 1950-99

Women's multi-partner behavior, multi-partner fertility, and pregnancy outcomes: findings from the 2004 Pelotas Birth Cohort

STUDY QUESTION

Do women with multi-partner fertility or multi-partner behavior conceive more often than women with a single partner?

SUMMARY ANSWER

Women with multi-partner behavior conceived more frequently and had more children than non-multi-partner women and multi-partner fertility women.

WHAT IS KNOWN ALREADY

Some women experience having biological children with more than one partner: those women are considered as multi-partner fertility. Women with multi-partner fertility have more children and are substantially less likely to have planned their first birth. Individuals with multi-partner fertility become parents at a younger age, largely with unintended first births, and often do so outside of marriage, compared to parents with two or more children from only one partner. Unmarried women, particularly, are at greater risk of having unintended births. Studies are still scarce and there is a need to assess the contribution of women's multi-partners fertility and multi-partner behavior to family composition, particularly in low- and middle-income countries.

STUDY DESIGN, SIZE, DURATION

This longitudinal birth cohort study evaluated 1215 mothers whose children belonging to the 2004 Pelotas Birth Cohort were their first pregnancy, and who attended the perinatal, 48-month, 6-year, and 11-year follow-ups. Information was obtained from responses to a questionnaire. The number of years at risk of having children was treated as the exposure, and woman's multi-partner behavior and multi-partner fertility, dichotomized as 'Yes' or 'No', were considered endogenous treatment variables.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Data from mothers with a first pregnancy, and with information available from the perinatal, 48-month, 6-year, and 11-year follow-ups, were evaluated. The exposures studied were women's multi-partner behavior and multi-partner fertility (i.e. conceiving/giving birth), and the outcomes evaluated were the number of pregnancies, the number of children currently alive, and experience of unintended pregnancies from the birth of the child belonging to the 2004 birth cohort until 11 years later. Crude and adjusted risk ratios (RRs) were estimated through Poisson regression with endogenous treatment effects, robust standard errors, and their respective 95% CI.

MAIN RESULTS AND THE ROLE OF CHANCE

Multi-partner behavior women had 16% (RR 1.16; 95% CI: 1.08-1.25) and 11% (RR 1.11; 95% CI 1.03-1.19) greater risk of having a new pregnancy and having more children alive, respectively, than those with non-multi-partner behavior. Women with multi-partner fertility had a 23% (RR 1.23; 95% CI: 1.11-1.37) and 20% (RR 1.20; 95% CI: 1.08-1.33) higher risk of having a new pregnancy and having more children alive, respectively, than single-partner fertility mothers. Women who had multiple partners (i.e. behavior), as well as those with multi-partner fertility, showed a lesser proportion of unintended pregnancies when compared to the non-multi-partner ones (34.08%; 95% CI: 28.12-40.60 vs 36.17%; 95% CI: 31.93-40.63), compared to their counterparts' single partners fertility (33.16%; 95% CI: 26.83-40.17 vs 36.26%; 95% CI: 31.85-40.92), although these findings were not statistically significant.

LIMITATIONS, REASONS FOR CAUTION

The mothers who were not included in the study owing to missing data for some of the follow-up had 5-11 years of education, a low socio-economic level, and were younger, thus the number of pregnancies may be underestimated because these groups presented a high number of pregnancies and children alive. We did not have information about the complete woman's conjugal history. Therefore, misclassification error of the exposure may be present and, consequently, the measures of association may be underestimated. Furthermore, this study was not truly representative of the Pelotas study female population.

WIDER IMPLICATIONS OF THE FINDINGS

In this study of multi-partner behavior and fertility, women who have multiple partners may be less likely to get married and have a stable partner. Compared to single-partner women, multi-partner fertility and multi-partner behavior women may predominantly become pregnant for the purpose of having children, rather than accidentally.

STUDY FUNDING/COMPETING INTEREST(S)

This article is based on data from the study 'Pelotas Birth Cohort, 2004' conducted by the Postgraduate Program in Epidemiology at the Universidade Federal de Pelotas, with the collaboration of the Brazilian Public Health Association (ABRASCO). From 2009 to 2013, the Wellcome Trust supported the 2004 birth cohort study. The World Health Organization, National Support Program for Centers of Excellence (PRONEX), Brazilian National Research Council (CNPq), Brazilian Ministry of Health, and Children's Pastorate supported previous phases of the study, and also was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior-Brasil (CAPES)-Finance Code 001. The authors declare that the supported agencies have no role in any step of performing this study. No conflicts of interest exist.

TRIAL REGISTRATION NUMBER

N/A.

Union Instability and Fertility: An International Perspective

In this article, we analyse the relationship between union instability and cumulated fertility among ever-partnered women in several regions across Europe and the Americas with different patterns of demographic behaviour in terms of fertility levels, union instability and fertility across partnerships. We hypothesise that the relationship between union dissolution and fertility might be less negative in contexts where repartnering is more prevalent. The analysis is performed on a large dataset of 25 countries, combining information from the Harmonised Histories of the Generation and Gender Programme with our own harmonisation of survey data from three Latin American countries. This allows for the inclusion of countries with differing prevalence of union instability as measured by (a) the proportion of women who separated by age 40, and (b) the proportion who repartnered by age 40. We first examine the prevalence of separation and repartnering during reproductive ages across regions, and we estimate the proportion of cumulated fertility attributable to unions of different ranks using a decomposition method. We then analyse the links between union instability and the number of children born by age 40 among ever-partnered and ever-repartnered women, using Poisson regression. Despite observing a high degree of heterogeneity in the proportions of births occurring in the context of repartnering both within and between regions, we find a pattern where a greater prevalence of repartnering by age 40 is accompanied by higher cumulated fertility in second or subsequent unions. Our multivariate findings reveal a negative statistical relationship between separation and cumulated fertility that is partially offset by repartnering in some contexts, and that the time spent in a union during the reproductive lifespan is a key determinant of cumulated fertility, regardless of national context and independently from age at union formation and union rank.

Lifetime parenthood in the context of single- and multiple-partner fertility

The proportion of life spent caring for dependent children is a defining feature of life courses. This study uses Swedish register data to analyze the period of life spent as parents to children no older than 18 as a salient difference between single- and multiple-partner fertility trajectories. Individuals who have children with more than one partner spend a much longer time as parents to dependent children than those who have children with one partner, on average 8.2 more years among men and 6.2 more years among women. Cross-partner birth spacing is a more powerful proximate cause of this gap than completed fertility. We argue that an extended time parenthood is part and parcel to multi-partner fertility and discuss implications of this.

Pathways to Parenthood in Social and Family Context: Decade in Review, 2020

OBJECTIVE

This article reviews research from the past decade on patterns, trends, and differentials in the pathway to parenthood.

BACKGROUND

Whether, and under what circumstances, people become parents has implications for individual identity, family relationships, the well-being of adults and children, and population growth and age structure. Understanding the factors that influence pathways to parenthood is central to the study of families and can inform policies aimed at changing childbearing behaviors.

METHOD

This review summarizes recent trends in fertility as well as research on the predictors and correlates of childbearing, with a focus on the United States and on research most relevant to family scholars. We document fertility differentials and prevailing explanations for variation across sub-groups and discuss alternative pathways to parenthood, such as adoption. The article suggests avenues for future research, outlines emerging theoretical developments, and concludes with a discussion of fertility policy.

RESULTS

U.S. fertility has declined in recent years; whether fertility rates will increase is unclear. Elements of the broader social context such as the Great Recession and increasing economic inequality have impacted pathways to parenthood, and there is growing divergence in behaviors across social class. Scholars of childbearing have developed theories to better understand how childbearing is shaped by life course processes and social context.

CONCLUSION

Future research on the pathways to parenthood should continue to study group differentials, refine measurement and theories, and better integrate men and couples. Childbearing research is relevant for social policy, but ideological factors impact the application of research to policy.

Intergenerational Transmission of Multipartner Fertility

Using data from administrative registers for the period 1970–2007 in Norway and Sweden, we investigate the intergenerational transmission of multipartner fertility. We find that men and women with half-siblings are more likely to have children with more than one partner. The differences are greater for those with younger versus older half-siblings, consistent with the additional influence of parental separation that may not arise when one has only older half-siblings. The additional risk for those with both older and younger half-siblings suggests that complexity in childhood family relationships also contributes to multipartner fertility. Only a small part of the intergenerational association is accounted for by education in the first and second generations. The association is to some extent gendered. Half-siblings are associated with a greater risk of women having children with a new partner in comparison with men. In particular, maternal half-siblings are more strongly associated with multipartner fertility than paternal half-siblings only for women.

Is Stepfamily Status Associated With Cohabiting and Married Women's Fertility Behaviors?

Children from prior relationships potentially complicate fertility decision-making in new cohabitations and marriages. On the one hand, the "value of children" perspective suggests that unions with and without stepchildren have similar-and deliberate-reasons for shared childbearing. On the other hand, multipartnered fertility (MPF) research suggests that childbearing across partnerships is often unintended. Using the 2006-2010 National Survey of Family Growth and event-history models, I examine the role of stepfamily status on cohabiting and married women's fertility and birth intendedness, with attention to union type and stepfamily configuration. Adjusting for covariates, women in stepfamily unions are more likely to have a first shared birth in a union than women in unions in which neither partner has children from past relationships, but stepfamily births are less likely to be intended than unintended. Further, this association varies by union type: married women have similar birth risks across stepfamily status, but births are less likely to be intended in marital stepfamilies. For cohabitors, women in a stepfamily are more likely to have a birth than women in nonstepfamily unions, with no differences in intendedness. Configuration (whose children and how many) also matters; for instance, women with one child from a past relationship are more likely to have a birth and to have an intended than unintended birth than women with other stepfamily configurations. It appears that children from either partner's prior relationships influences subsequent fertility decision-making, undermining the utility of the "value of children" perspective for explaining childbearing behaviors in complex families.

Is Stepfamily Status Associated With Cohabiting and Married Women's Fertility Behaviors?

Children from prior relationships potentially complicate fertility decision-making in new cohabitations and marriages. On the one hand, the "value of children" perspective suggests that unions with and without stepchildren have similar-and deliberate-reasons for shared childbearing. On the other hand, multipartnered fertility (MPF) research suggests that childbearing across partnerships is often unintended. Using the 2006-2010 National Survey of Family Growth and event-history models, I examine the role of stepfamily status on cohabiting and married women's fertility and birth intendedness, with attention to union type and stepfamily configuration. Adjusting for covariates, women in stepfamily unions are more likely to have a first shared birth in a union than women in unions in which neither partner has children from past relationships, but stepfamily births are less likely to be intended than unintended. Further, this association varies by union type: married women have similar birth risks across stepfamily status, but births are less likely to be intended in marital stepfamilies. For cohabitors, women in a stepfamily are more likely to have a birth than women in nonstepfamily unions, with no differences in intendedness. Configuration (whose children and how many) also matters; for instance, women with one child from a past relationship are more likely to have a birth and to have an intended than unintended birth than women with other stepfamily configurations. It appears that children from either partner's prior relationships influences subsequent fertility decision-making, undermining the utility of the "value of children" perspective for explaining childbearing behaviors in complex families.

MARRIAGE AND DISSOLUTION AMONG WOMEN'S COHABITATIONS: VARIATIONS BY STEPFAMILY STATUS AND SHARED CHILDBEARING

Cohabiting unions increasingly involve children, either born during the union and/or from prior relationships (i.e., stepchildren). Drawing from arguments about the institutionalization of cohabitation and stepfamilies as well as the family systems perspective, this paper examines dissolution and marriage risks among women's cohabiting unions by stepfamily status, configuration (which partner has children) and shared intended and unintended fertility using the 2006-2013 National Survey of Family Growth. A minority (32%) of 1st cohabitations, but the majority of 2nd (65%) and 3rd (75%) cohabitations, are stepfamilies. Stepfamily cohabitations are less likely to transition to marriage compared to non-stepfamily unions, especially among complex stepfamilies (both partners have children), but neither stepfamily status nor configuration affect dissolution. Shared intended and unintended births are associated with dissolution and marriage risks but largely only for non-stepfamily cohabitations, suggesting that shared childbearing is only indicative of the institutionalization for cohabitations that are not stepfamilies.

Fathers' Imprisonment and Mothers' Multiple-Partner Fertility

We consider the intersection between two striking U.S. trends: dramatic increases in the imprisonment of fathers and increases in the proportion of mothers who have children with more than one partner (multiple-partner fertility, or MPF). Using matched longitudinal administrative data that provide unusually comprehensive and accurate information about the occurrence and timing of imprisonment, fertility, and MPF for the population of the state of Wisconsin, we consider the relationship between paternal imprisonment and MPF among unwed mothers. Employing discrete-time event history analysis with multinomial logistic regression, we model the occurrence and timing of the mother's second birth, distinguishing between a birth with the same father and a birth with a different father, and distinguishing between current imprisonment and a history of imprisonment. We find that current imprisonment is associated with an increased likelihood of MPF and a decreased likelihood of fertility with the same father (compared with no additional birth) and that a history of imprisonment is associated with increased MPF in some models but not in our preferred model. To control for unobserved heterogeneity among mothers and assess the evidence of a causal effect of fathers' imprisonment, we also employ the case-time-control method, a fixed-effects method for the analysis of nonrepeated events. Results suggest that fathers' current imprisonment may increase mothers' MPF. Policy implications are discussed.

Fertility after repartnering in the Netherlands: Parenthood or commitment?

In this paper, we focus on childbearing after the dissolution of the first marital union. The discussion of what drives fertility decisions after dissolution has been largely dominated by the arguments that: (a) people want to have a child as a way to achieve the adult status of parenthood (the "parenthood hypothesis"), and that (b) a shared child can signal the partners' commitment to each other (the "commitment hypothesis"). Earlier studies have reported mixed findings for these hypotheses. We used couple data from several Dutch surveys (N = 8094 couples of which 10.2% included a repartnering partner) and utilized a new analytical approach to test the commitment proposition in particular. Our main findings lend support to the parenthood hypothesis when it comes to men's transition to a union-specific birth and to the commitment hypothesis when considering women's transition. Whereas for men, children from a prior union decrease the likelihood of transitioning to a union-specific birth, for women children from a prior union do not matter. That is, women would find it important to confirm the union as a family despite the presence of children. Additional support for the commitment hypothesis for women is that being in a second union rather than first union increases chances of parity progression.

New Partners, More Kids: Multiple-Partner Fertility in the United States

Declining rates of marriage and overall increases in union instability, combined with high levels of unintended and nonmarital fertility, create the possibility for parents to have children with more than one partner, called multiple-partner fertility, or MPF. The unique characteristics of families with MPF present data and other logistical challenges to researchers studying the phenomenon. Drawing from recent studies and updated data, I present new estimates of MPF that show that about 13 percent of men aged 40 to 44 and 19 percent of women aged 41 to 49 have children with more than one partner, with a higher prevalence among the disadvantaged. Compared to parents with two or more children by only one partner, people with MPF become parents at younger ages, largely with unintended first births, and often do so outside of marriage. This article touches on the implications of MPF for families and concludes by discussing the theoretical difficulties in studying MPF and the challenges it presents to public policy.

Childbearing across partnerships in Australia, the United States, Norway, and Sweden

This article compares mothers' experience of having children with more than one partner in two liberal welfare regimes (the United States and Australia) and two social democratic regimes (Sweden and Norway). We use survey-based union and birth histories in Australia and the United States and data from national population registers in Norway and Sweden to estimate the likelihood of experiencing childbearing across partnerships at any point in the childbearing career. We find that births with new partners constitute a substantial proportion of all births in each country we study. Despite quite different arrangements for social welfare, the determinants of childbearing across partnerships are very similar. Women who had their first birth at a very young age or who are less well-educated are most likely to have children with different partners. The educational gradient in childbearing across partnerships is also consistently negative across countries, particularly in contrast to educational gradients in childbearing with the same partner. The risk of childbearing across partnerships increased dramatically in all countries from the 1980s to the 2000s, and educational differences also increased, again, in both liberal and social democratic welfare regimes.