Understanding how having children can affect your health

Is having children bad for your health? There are two main reasons why it's important to ask this question.

The first reason is that while life expectancy in developed countries has increased, so too has health inequality among older people. In just one country, there can be a 20-year gap in life expectancy across different social strata of the population, reflecting the fact that heightened morbidity and longer periods spent with a lower quality of life have become serious threats for large segments of the population. It is critical to identify the risk factors that lead to health disparities at older ages.

The second reason is that a majority of advanced countries have experienced a decades-long decline in fertility levels. Among these countries, however, there is astounding diversity in the total fertility rate. Consequently, fertility trajectories have become much more diverse compared to the past.

So, is it possible that there is a relationship between fertility and health? The short answer to this question is yes. As you can imagine, the real answer is considerably longer and much more complicated. The research behind it has looked at several countries, health outcomes, fertility characteristics, and age groups.

Studying chronic conditions

An initial study investigated the association between fertility histories and the presence of chronic conditions later in life in 11 European countries. In particular, it looked at individuals who were 50 years old or older in 2013 – part of the Survey of Health, Ageing and Retirement in Europe (SHARE) – and studied how the number of children, the age at first and last birth, the length of birth intervals, and experiencing the death of a child influenced self-reported chronic or long-term illness and chronic diseases diagnosed by a doctor. Results showed that age at first birth is more relevant than number of children for health outcomes at older ages: those who experienced teenage pregnancy showed a higher risk of developing chronic conditions later in life. This is likely due to the fact that young parents often have fewer resources and social support to deal with the stress of parenthood and to cope with the economic strain of the situation. The negative consequences of teenage pregnancy can cumulate over the life course and result in worse health outcomes later in life. Moreover, in socio-democratic and continental countries (e.g. Sweden and Austria), the association between fertility and chronic conditions – in particular between age at first birth and long-term illnesses – is significant among women, but not among men.

Looking for links

To understand in more detail whether these associations remain valid when analysing more objective measures of health, another study used the National Child Development Study (United Kingdom), which follows the lives of more than 17,000 infants born in a single week in March 1958. In 2002, more than 9,000 of the survey’s participants provided biomedical data that allows us to look at the association between fertility histories – number of children, age at first and age at last birth – and biomarkers for cardio-metabolic risk and respiratory function among both men and women at age 44-45. Results show that fertility histories are associated with these objective indicators of health and that key associations are with age at first and at last birth, rather than with number of children. Specifically, there is an inverted J-shape relationship between age at first birth and biomarkers indicative of worse health, with poorer outcomes for those with very young ages at entry to parenthood and increasingly better outcomes for older parents. A very young age at last birth is also associated with negative health outcomes, especially among women.

The impact of a partner

Since parenthood and partnership are greatly intertwined and might create interdependent effects on long-term health, a final study explored the relationship between fertility and partnership histories and cognitive functioning in adults 50 years old and older in the United States. This study used the Health and Retirement Survey (HRS) and the results showed that most of the relationship between fertility and partnership history and cognition later in life is explained by childhood health, socioeconomic early life conditions, and current sociodemographic characteristics. However, those individuals who have never been married, and in particular those who have never been married and have had no children, report a significantly lower level of cognitive functioning in older age. This is especially marked among women.

The results of this research highlight that it is important to consider not only the number of children, but also the timing of childbirth and the concurrent partnership history in order to understand the influences of fertility on health later in life. Hence, new family policies should take these issues into account and ensure that more vulnerable groups of the population – such as teenage mothers – are protected against the cumulative negative health effects of specific fertility trajectories.

Dr Maria Sironi is Associate Professor in Quantitative Sociology at University College London. Her British Academy Postdoctoral Fellowship-funded research project is titled ‘Is Having Children Detrimental to Your Health? A Cross-national Investigation of Fertility Trajectories and Health in Later Life’.