Parenthood and health: a cross-national and longitudinal investigation of fertility trajectories and health in later life

The Office for National Statistics of the United Kingdom has released in November 2014 the latest statistical analysis on life expectancy in England and Wales (ONS, 2014). The bulletin reveals that life expectancy for newborn babies has increased by at least 5 years for boys and 3.4 years for girls over the last 20 years.

However, while life expectancy in developed countries has increased, so too has health inequality among older people. Within countries, there can be a 20-year gap in life expectancy across different social strata of the population, and this is mainly due to diverse health conditions among advantaged and disadvantaged elderly (Marmot, 2005). As a consequence, heightened morbidity and longer periods spent with a lower quality of life have become serious threats for larger segments of the population. It is critical to identify the risk factors that lead to health disparities at older ages.

Concurrently, a majority of advanced countries have experienced a decline in fertility levels for decades. Among these countries, however, there is astounding heterogeneity in the total fertility rate. During the 1990s, 14 European countries reported a total fertility rate below 1.3, especially in Southern, Central and Eastern Europe (Billari et al., 2004). Other countries, like Denmark and the Netherlands, reported relatively high fertility in the same period. In the last decade we observed a reversal in fertility rates (Myrskylä et al., 2009), with a positive HDI-fertility relationship at very high development stages. Additionally, the context in which childbearing takes place has changed substantially since World War II with a decrease in marriage rates, an increase in the age at first marriage and first birth, and in cohabitation and divorce rates. Consequently, fertility trajectories have become much more diverse compared to the past.

Aging populations with greater health inequalities and changes in union and fertility trajectories have been two of the most significant demographic trends of the last decades in industrialized countries. It is therefore crucial to study these two topics jointly, which has rarely been done so far, especially through a comparative lens. This project funded by British Academy (Reference pf150105), situated at the intersection of these two research areas, will fill this major gap in the literature, and investigate how fertility decisions are linked to health at old ages. I will do that by analyzing individuals’ union and fertility trajectory as a possible social determinant of health among the elderly in several developed countries.

Crucially, the study will shed light on the key mechanisms through which health inequalities develop over the life course. In particular, I will investigate the role of union and (in)fertility trajectories in shaping mental and physical health later in life. The main health outcomes to be investigated are chronic diseases (e.g. cancer, diabetes, obesity), depression, and disability, i.e. conditions that are driven by life style, environment, aging, and often associated with older age groups.

Fertility trajectories can be defined as the combination of the number of children, their timing, and the life course circumstances during childbearing. Childbirth can take place in very different conditions: parents can be married, cohabiting, dating, or single. They can be full or part-time workers or unemployed. Parents, when older, can become grandparents. Childbearing can also not take place at all in the life course of an individual.

It is necessary to consider all of these aspects that occur together with the childbearing experience. Past research shows that fertility can influence health and wellbeing later in life through manifold mechanisms (Grundy & Tomassini, 2005; Goisis & Sigle-Rushton, 2014). The most evident and direct mechanism is the physical impact of a pregnancy on women’s body. The effects of the pregnancy can bring along short-term disadvantages due to the physiological stress. However, giving birth to a child increases mothers’ stress resilience, their medical care, and their social integration. These effects can be mitigated or accentuated by the mother’s age, her partnership and employment status, the number of children already born etc. Breastfeeding is also known to have short and long-term effects on maternal health (Heinig & Dewey, 1997), such as preventing development of diabetes and heart diseases.

Other more indirect mechanisms, holding for both men and women, are related to the social status of being a parent, to the concurrent union trajectory, and to intergenerational transfers and social support implied by parenthood. Having children has been found to have both positive and negative effects on mental wellbeing and life satisfaction, depending on the number of children, partnership status, and timing of childbearing (Aassve et al., 2012; Kohler et al., 2005; Murphy, 1984; Demey et al., 2014). Yet, the long-term effects on health of union and fertility trajectories when considered as a whole are still unknown.

My research will consider the union and fertility trajectory from a holistic point of view, implementing the approach known as sequence analysis. Prior research has either focused on the link between the number of children or the age at first birth and later health (Grundy & Kravdal, 2014), or the association between life course events and health outcomes in the short run (Barban, 2013), and has not considered whole fertility trajectories or the interrelation of fertility with other life course trajectories, such as partnership history. Moreover, I will adopt a cross-national comparative perspective and consider the possible differential effects across societies. I will look at several European countries (using the Survey of Health, Ageing and Retirement in Europe), at the United Kingdom (using the English Longitudinal Study of Aging), and at the United States (using the Health and Retirement Survey for the United States). Health outcomes are affected by factors like environment and life style. Therefore different welfare regimes and cultural attitudes on childbearing and work support will influence health conditions among the elderly in different ways.

Maria Sironi will be a British Academy Postdoctoral Fellow at UCL-Institute of Education in London from September 2015. Her main research interests focus on life course analysis and transition to adulthood. In particular she investigated trends in the transition to economic independence of young adults in United States and Europe, and her current research project looks at implications of different fertility trajectories on mental and physical health outcomes at older ages. She completed her PhD in Demography at University of Pennsylvania in 2013, and has been a Postdoctoral Research Fellow in the Department of Sociology and Nuffield College at the University of Oxford until June 2015.