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Assisted Reproduction, Late Fertility and Childlessness

Interview with Melinda Mills and Maria Letizia Tanturri
Biological Clock
Source: LittleBee80

Who is considered a childless person in your research?

A childless person is defined as an individual having no biological or foster children.
In spite of the apparent simplicity of this definition, childless individuals form a very heterogeneous group defined essentially by a “non-event”. The concept of childlessness includes a variety of situations having different implications for the understanding of reproductive behaviour. We can distinguish childless individuals according to various criteria: For instance, according to the possible causes leading to this situation (e.g., sterility or sub-fertility, health problems or disability, difficulties in personal relationships, economic reasons, voluntary choice), or to the temporal perspective (i.e., whether it is a permanent or a temporary condition), and according to the degree of commitment to the decision (whether it is renegotiable or not).

What are the challenges in identifying those types of individuals?

A first challenge is linked to the distinction between permanent and temporary childlessness: The former is reached at the end of a one’s reproductive life, whereas the latter is a reversible result of delayed childbearing. If this difference can be identified for women more easily – because of their biological constraints – the same cannot be said for men whose limits of reproductive age are more blurred and dependent on the age of their partner.
A second challenge is represented by the distinction between those who voluntarily refuse motherhood and those who are unable to have children as a consequence of physical impediments or infertility (involuntary childlessness). Voluntary childless individuals are often described as “childfree”, as people who definitely never wanted (do not want) a pregnancy or children of their own, ever. They have no children and respond consistently and negatively to all the questions on intended childbearing. This apparently simple distinction however is far from straightforward. If we take into consideration, for instance, women who continually put off having children to the point where this is no longer possible (often defined as permanent postponers), then in this case, a behaviour that was originally voluntary might end up becoming involuntary because of the emergence of sterility impairments. The boundary between choice and constraint may also be indistinct in many other cases. For instance, failure to enter into a union may depend on choice (people may have little propensity towards family life) or on circumstances (inability to find a suitable partner). Moreover, a voluntarily childfree person may also change his or her mind at some point in life and wish for children. The early articulators are those who state from the beginning of their reproductive life their preference for a life without children. Conversely, the wavers are those who seem to have not yet decided whether they want to have children or not and they remain ambivalent.
However, the choice of remaining childless is mostly not a decision for or against parenthood, but rather a process in which ambiguity plays a role. Voluntary childlessness seems less important than expected in Europe: The New Eurobarometer data show that the proportion of women aged 18-40 who do not have children, do not want to have children in the future, or whose personal ideal number of children is zero are remarkably small: 3% on average. Once again there is a certain degree of cross-country variability, but only in the two German-speaking countries is the proportion around 6%. Among men voluntary childlessness seems slightly more spread on average (4%), but with a higher degree of variability (between 1% in Lithuania and up to close to 16% of the Netherlands).
Unfortunately in Europe it is not easy to find comparative survey data on this topic allowing to distinguish different typologies of childlessness. Within the FamiliesAndSocieties project we are therefore also carrying out qualitative interviews in three European countries (Hungary, Italy and Romania) on childless men and women over 45. The results will be available in 2016.

Do you have some numbers on general trends in Europe?

The trends in the prevalence of definite childlessness are remarkably similar across European countries: A peak in childlessness rates for the 1880-1910 birth cohorts, a more or less continuous drop across the 1910-1945 birth cohorts, and a steady rise across the cohorts born after the Second World War. The lowest proportion of childless women indeed are observed among the cohorts of women born after the war (1945-49) in most countries, while higher levels are usually registered both among the older and younger cohorts.

How do trends vary between the countries? Could you give us some examples?

As we said, permanent childlessness levels have recently increased across generations in most European countries, with the relevant exceptions of Denmark, Sweden, Latvia, Russia and Slovenia. Childlessness levels at ages 40-44 remains low (≤ 10%) in most Eastern European countries – Bulgaria, the Czech Republic, Estonia, Hungary, Lithuania, Poland, Portugal, Romania and Russia –, moderate (11-15%) in France, Belgium, Georgia, Germany, Norway, Slovak Republic, Slovenia, Sweden and the U.S., and high (around 20%) in Austria, Italy, Finland, the Netherlands and the UK. Male lifetime childlessness is increasing even more: We observe the highest rates (above 23% among men aged 45-49) in Finland, Italy, Germany, the UK and the Czech Republic.
In the last decade, most European countries have also experienced a remarkable rise in “temporary” childlessness levels at the age of 30-35 almost everywhere: With a regional variability from 10% – again in most Eastern European countries – to over 40% (in Portugal, Ireland, Italy, the Netherlands, Finland and Austria). High levels are observed surprisingly also in Hungary (around 35%), which differs enormously from the rest of the Eastern countries.
The spread of the phenomenon is accompanied by attitudes and value change since not having a child is now becoming more and more acceptable and even considered the best option in many countries.

What are the main causes for this variation?

At the macro level, childlessness is more common in countries that are more oriented toward individualism and less traditional values. Moreover, the younger generation born around 1965 is still strongly associated with traditional family-related variables: For instance, the prevalence of childless women is higher in countries where the proportion of women ever married is also higher and where marriage is postponed until higher ages. Surprisingly, the diffusion of childlessness is only weakly associated to structural changes, such as women’s increased education level and labour market participation.

What are the most important differences between men and women regarding childlessness?

Studying childlessness among men is not an easy task, as most of data on reproductive behaviour are commonly available only for women. Nevertheless, it is worthwhile to study. In general, from our study, we notice that the prevalence of childlessness among men is higher than among women, with the exception of Georgia: The ratio between proportions of childless men and women is 1.56 on average, but ranges from 0.86 in Georgia to 2.24 in the Czech Republic.
One reason behind these differences is that men can have children later in life, while most fertility data covers only ages up to 49 years. However, very few men, approximately 1-3% at most, do become fathers at older ages in contemporary Europe. This is because most men have female partners who are not much younger than they are themselves. Mistakenly attributed biological paternity can be another cause explaining gender gaps, but it has been estimated to represent around 3% in contemporary Western populations. Together, these two effects of unknown or mistaken paternity may be assumed to cancel each other out. Higher childlessness levels among men is compensated by higher multi-partner fertility compared to women.
Among men in their early 30s, Italy, the Netherlands, Germany and Austria have the highest proportion of childlessness at around 60% or more, and Romania, France, Poland, Lithuania and Russia have the lowest at below 40%. For men who are in their early 40s, the Netherlands, Germany, Finland, the Czech Republic and Italy have proportions above 25%. When we look at the closest proxy for lifetime childlessness, Finland, Italy, Germany, the UK and the Czech Republic are at the top in the 45-49 age group (male cohorts born around 1956-65) with around one out of four men remaining childless, while in Estonia, Russia and Georgia, only one in 10 men are childless. It would be interesting to know if men are exhibiting more of a postponement behaviour in countries such as the Netherlands and Austria, or whether these countries are experiencing a cohort change so that significantly more men will end up childless compared to slightly older cohorts.
For men, the association between educational level and childlessness has not changed much in recent cohorts: Less-educated men have the highest rates of childlessness in 14 out of 18 countries.
In sum, higher childlessness is usually more common among highly educated women and less educated men, but with a certain degree of variability between countries. In some western European countries these associations may be weakening or disappearing (as in Finland, for instance).

To what extent is the scope of childlessness defined by the age groups considered when measuring this phenomenon?

Childlessness at younger ages is usually seen as part of a strategy of postponement, waiting for the “right moment and the suitable circumstances” to have children, but as soon as women approach their late 30s it is possible that childlessness results either from a definitive choice or from infertility problems that may me more common among older women (and men).

Regarding the role of Assisted Reproductive Technologies (ART), to what extent does it have an impact on societies?

Infertility is a condition that influences a sizeable number of couples around the world. Couples who experience infertility often opt for Assisted Reproductive Technology (ART) procedures. Europe is a world leader in both the postponement of childbearing to later ages and also the development and utilisation of ART. The regulation, financing and utilisation, however, differs widely across countries. The rise of in vitro fertilization (IVF) and its various variations and extensions, which are now often included under the umbrella of ART, has gained considerable attention and concern among the medical community, religious leaders, bioethicists and the general public.
Although it is clear that nations have an interest in promoting the safety and welfare of parents and their offspring, there is large variation in how these fundamental goals are interpreted and realised. ART has been at the heart of considerable scrutiny and debate, not only for medical, but also often for cultural, ethical and religious reasons. The move towards legislation was also often prompted by media reports of particular cases such as 65-year-old mothers, sperm donors who fathered hundreds of children, posthumous fatherhood, sex selection of embryos and reproductive tourism. IVF pioneers habitually faced heated moral questions and protest from a variety of religious organisations that largely objected to the destruction of fertilised eggs and raised concerns regarding whether these eggs had the status of a ‘human being’. In 1987, the Catholic Church published the view that IVF is ‘morally illicit’ (Donum Vitae), which has likely impacted policy formulation and utilisation in some countries.
ART use in individual countries, and even regions within countries, is strongly affected by their overall regulatory and legal framework stipulating costs of ART to patients, socially restricted access rules, number of cycles reimbursed, as well as limiting some ART practices and methods. Considerable differences in the regulatory environment and costs of ART treatment between countries has also led to the growth of ‘cross-border care’ or ‘reproductive tourism’. This is the case when patients travel abroad to obtain treatments that are unavailable (e.g., surrogacy) or when these services are prohibited to them due to their sexuality or relationship status (e.g., lesbians, single women, unmarried cohabiting couples), or they oppose policies (e.g., non-anonymity of donor) in their home country or travel in search of higher success rates (e.g., higher number of embryos transferred).

What are your biggest concerns regarding ART in Europe ?

There are many serious concerns regarding ART in Europe. For example:

  • A lack of clear policies based on medical, ethical advice: Many new treatments emerge and policies often lag behind (e.g., in relation to surrogacy, 3 parents, etc.);
  • ART policies that are not only made on medical grounds, but also involve the influence of religious groups and others in policy formation (which may have adverse medical consequences such as the transfer of many embryos due to belief that fertilized eggs are alive);
  • Lack of knowledge about the gaps between formal ART policies and actual practices in clinics, unclear sanctions and regulations;
  • A lack of detailed age-related attempts and success rates for treatments in Europe;
  • Lack of attention to the welfare of ART children and their rights (e.g., in relation to anonymity of donors and child’s right to know biological parents);
  • Little focus on employment and leave policies for patients undergoing ART treatment;
  • Lack of knowledge about the extent of cross-border care and what happens with parents and children in terms of their care when they return after treatments;
  • The commercialization of ART and cross-border care seems to grow, but we lack empirical data to understand the numbers and consequences; and,
  • Informed consent – when patients engage in cross-border care, do they have time to consider changes or other issues related to treatment?

Could you summarise your most relevant findings for FamiliesAndSocieties so far?

Regulation of ART
There is a large diversity in the regulation of ART across time and between countries. Over the past 15 years, there has been a clear trend towards more inclusive social policies (such as including unmarried women, gays and lesbians) and stricter regulation in the number of embryos that can be transferred. ART utilisation is also strongly related to both national regulation and financing, but also with norms and values. Societal norms related to whether the embryo is a human being – often related to religious values – support for infertile couples and rights for single mothers, gays and lesbians are strongly correlated to national policies. This suggests that future European policy making also needs to take into account the importance of national attitudes and norms. We show empirically for the first time that national level norms are related to ART policies, usage and affordability. We conclude that it is unrealistic to harmonise ART policy on all grounds across Europe. Working towards a minimal consensus of general principles and standards for safety and quality, and better data and monitoring would be more optimal.

Demographic consequences of ART
In a recent deliverable, we concluded that ART has a negligible impact on national fertility rates, thereby suggesting that it is not an effective policy instrument to counter low fertility. Furthermore, we showed that the recent increase in twin births in Europe can be attributed to ART usage. A case study of Italy reveals that ART mothers were more likely to deliver prematurely, even when controlling for maternal age.
We also found that there are large national differences in self-perceived infertility, particularly between the ages of 35 to 39 and within this group between different countries. We found a strong increase of ART users at advanced ages above 40, with sharp variations by country and the type of treatment. The majority of ART treatments (around 45%) still take place at age 34 and under, followed by those between 35 to 39 (around 38%), and then those aged 40 and over (around 17%). There was a strong growth in the ART usage by women over 40 between 1998 and 2000, particularly in Iceland, Denmark and Italy.
Since there was a surge in older women receiving these treatments, we found that their effectiveness were very low at older ages. We found that higher maternal age is paired with a decreased success rate of IVF treatments for those aged 40 and over of around 10% (delivery) and 20% (pregnancy), compared to those who were 34 years and under at 30% (delivery) and 35% (pregnancy), respectively. This work tends to challenge claims that women should freeze their eggs and have children very late via ART as a means of work-life reconciliation, showing that it is not highly effective at older ages.
We showed that there has been a dramatic increase in twinning rates since the 1970s, with rates more than doubling in many countries from the mid-1970s to the early 2000s. Since there have also been strong increases in maternal age at birth, which is linked to twinning, we explored whether it was birth postponement or ART that contributed to the growth of the twinning rate. We demonstrated that the majority of the changes in the twinning rate — or around two-thirds — can be attributed to ART, compared to only around one-third related to the advanced age at childbearing.
Future policy directives should focus on ensuring that this growing group of ART users and postponers above the age of 40 are aware of the limited success rates of ART at advanced ages.

What are you planning to investigate until the end of the project?

ART research
In our on-going research we are also examining the cognitive and educational outcomes of ART children and the parenting style of ART parents versus those who were conceived naturally.
In another paper we use ART data from 46 fertility clinics in six European countries to examine the reasons for cross-border care, linking the search for care with national policies.

ART policy database
In our next deliverable we collect and publically release policy data from over 15 years (1993-2014) in around 40 countries in addition to economic, demographic and attitudinal data from cross-national surveys to produce a new publically available dataset. The data includes 35 European countries and for comparative purposes, comparable industrialized societies such as the United States, Canada, Japan and China. ART-related policies include couple and sexuality requirements; number of embryos to transfer and age restrictions; cryopreservation; donation; donor anonymity; micromanipulation; oocyte maturation; selective foetal reduction; Pre-implantation Genetic Diagnosis (PGD); IVF surrogacy; experimentation on (pr)embryos; cloning; gender selection; posthumous insemination; type of insurance; amount of financial coverage; affordability. Each policy is divided into guidelines, regulations or legislation, and general practices.

Dr Melinda Mills (right) is Nuffield Professor of Sociology at the University of Oxford, United Kingdom. Her main research areas are currently in the area of combining a social science and genetic approach to the study of behavioural outcomes, with a focus on fertility, partnerships and assortative mating.

Dr Maria Letizia Tanturri (left) is Associate Professor of Demography at the Department of Statistics at the University of Padova, Italy. Her research is currently focusing on characteristics and determinants of men and women without children, gender roles and use of time, the cost of children and changes in family and intergenerational relations. She is also interested on the determinants, evolution and outcome of artificial insemination.


Both researchers are involved in the project “FamiliesAndSocieties – Changing families and sustainable societies: Policy contexts and diversity over the life course and across generations”, coordinated by Stockholm University. This collaborative research project is financed in the European Union’s Seventh Framework Programme (grant no. 320116) © Max Planck Society for the Advancement of Science.