The future of fertility

The decline in the global total fertility rate is becoming one of the defining demographic challenges of the twenty-first century. While the global population continues to grow overall, birth rates in many developed and middle-income countries have been below replacement level for decades. This contradiction highlights a deeper transformation in modern society: people are living longer, but fewer children are being born. Current projections suggest that without intervention, the global population itself may begin to decline between 2060 and 2080.

This alarming reality formed the background to a recent report published by Merck on the future of fertility, and was the subject of a forum organised to discuss these issues and potential ways to mitigate them.

Public discussion about falling birth rates is often emotionally charged and politically polarised. Some argue that younger generations are choosing careers or lifestyle over family life. Others frame declining fertility as a cultural crisis, augmented by the uncertainties of the current geopolitical state of the world. Yet the evidence increasingly suggests that the issue is far more structural than ideological. Most people still express a desire to have children. The problem is that modern economic, social, and biological pressures are making it harder both to start families and to achieve the family size that people want.

One of the clearest findings from recent demographic research, including the State of World Population 2025 report by the United Nations Population Fund, is that financial and economic pressures are central drivers of declining fertility. The decision to delay or avoid parenthood is strongly linked to the rising cost of living, expensive childcare, insecure employment, housing costs and inadequate family support policies. In many countries, younger generations face a level of economic uncertainty that previous generations did not experience to anything like the same extent. Many young adults spend their later twenties and thirties attempting to achieve financial stability, before they consider having children.

At the same time, important social changes have reshaped family formation. The expansion of higher education and professional opportunities for women, combined with reliable contraception, has been one of the greatest social advances of the modern era. Women are increasingly pursuing higher education, careers and financial independence before starting families. However, workplace structures and social policies have not evolved quickly enough to support this reality. As a result, many people delay parenthood while establishing careers or finding stable partnerships. The average age of mothers has risen to around 30 years, while fathers are – on average – nearly 34 years old.

This delay has important biological consequences that are often poorly understood by the public. Human fertility declines with age, particularly for women, and while assisted reproductive technologies can help some couples conceive later in life, they cannot overcome age-related reproductive decline.

One of the most overlooked contributors to declining fertility rates is limited fertility knowledge. There remains widespread misunderstanding about reproductive ageing and the realistic success rates of fertility treatments such as IVF. For decades, sex and relationship education has focused primarily on contraception and the prevention of sexually transmitted infections. Fertility education, by contrast, has received comparatively little attention.

Research from the Netherlands demonstrates the importance of timing in achieving the desired family size. Couples hoping for a 90 percent chance of conceiving one child naturally are advised to begin trying by age 32. For two children, the recommended age falls to around 27 years old. The impact of IVF is small, and delays significantly reduce the likelihood of achieving larger families. Furthermore, fertility preservation options such as egg freezing are sometimes misunderstood, or portrayed as 'insurance' for future fertility rather than as tools that may improve possibilities under certain conditions.

Data from the London Women's Clinic shows that between 2008 and 2022, more than 2000 patients froze their eggs, yet only a small proportion later returned to use them. While fertility preservation offers important reproductive choices, often at significant financial cost, it should not create false reassurance that fertility can be indefinitely postponed without consequences.

Significant inequalities also remain in access to fertility treatment. The Human Fertilisation and Embryology Authority reports that around 54 percent of IVF cycles in Scotland are NHS-funded, compared with only 24 percent in England. It would require considerable optimism to believe that the recent recommendation from the National Institute for Health and Care Excellence that the NHS should provide up to six IVF cycles will be implemented in the near future (see BioNews 1334), particularly when the PET NHS Fertility Funding Tracker shows that only two out of 42 Integrated Care Boards in England currently offer the recommended three cycles (see BioNews 1326).

Given these challenges, what can governments and societies realistically do to address declining fertility rates? There is no simple or immediate solution. However, evidence suggests that supportive family policies can make a meaningful difference, even if their effects are sometimes temporary.

Scandinavian countries during the late 1990s and early 2000s demonstrated that progressive social policies, including subsidised childcare, paid parental leave, tax incentives, and workplace flexibility, can help stabilise fertility rates and reduce barriers to parenthood. Affordable childcare is especially important. In many countries, childcare costs consume a large proportion of household income, making it financially difficult for couples to have more children. Housing support for young families, improved parental leave, and flexible working arrangements can also reduce the economic pressures associated with family life.

In the longer term, improving fertility awareness and reproductive education is essential, and is championed by the Royal College of Obstetrics and Gynaecology and the European Society of Human Reproduction and Embryology. Fertility education is now included within the UK education system, but broader awareness remains limited. Education systems should provide more balanced information about reproductive health, fertility decline, and the limitations of assisted reproductive technologies. Better fertility education could help both women and men make more informed decisions about family planning earlier in life.

Workplaces also play an important role. In addition to improved parental leave, supporting employees in seemingly minor ways, such as greater awareness and flexibility for those undergoing fertility treatment.

Some countries have already explored innovative approaches. Fertility assessment clinics – such as those developed in Copenhagen, Denmark – aim to help people better understand their reproductive health, and how it may change over time. Evidence suggests that fertility education can improve knowledge and may encourage earlier consideration of family formation.

At the same time, societies must recognise that ageing populations are likely to remain a long-term reality. Japan offers an important example, through its investment in technologies that support independent living for older adults. Rather than focusing exclusively on increasing birth rates, Japan's approach recognises that adapting to demographic ageing is also essential.

Ultimately, the fertility crisis reflects broader social and economic tensions within modern life. Declining birth rates are not simply the result of changing values or reduced interest in family life. They are shaped by economic insecurity, delayed life transitions, inadequate social support and limited fertility education, with the biological realities of reproductive ageing dealing a further – and too often final – blow.

Governments wishing to address falling fertility rates must focus on creating conditions in which people feel financially secure, socially supported, and informed enough to build the families they desire. This will require long-term planning and investment.

The challenge is not simply encouraging people to have more children. It is to create societies in which having children no longer feels economically risky, professionally damaging, or biologically out of reach.