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Overview of infertility prevalence in Europe: a global problem Volume 21, issue 3, Juillet-Août-Septembre 2019

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Tables

It is difficult to estimate the prevalence of infertility, due to different definitions used in the available studies and lack of population based studies [1].

According to the World Health Organization, infertility is defined as “a disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse” [2].

Or according to the latest ICMART-ASRM-ESHRE that is an extended version of the previous one, it is also “due to an impairment of a person's capacity to reproduce either as an individual or with his/her partner”. This last definition take into account also the possible different kind of partner conditions including same sex couples [3].

In Europe the prevalence of infertility could be considered to be from 6.6% to 16.7% [4]. In a quite recent estimation made by Fertility Europe and ESHRE in 2013 [5], the portion of European citizens suffering from infertility was 25 million. The disease is represented in both members of the couple. Males are the only responsible in the 20-30% of cases of infertility, while they contribute with females to the 50% of overall cases [6].

Among the different female causes of infertility we found the first contributor in advanced maternal age with the decrease of the number and quality of oocytes [7]; then Sexually Transmitted Diseases (STD), that could cause tubal blockage; hormonal factors; genetic causes; pollution and environmental factors [6]. Among male causes of infertility we recognize: advanced paternal age that decrease the number and the quality of spermatozoa; infection diseases; hormonal and genetic causes; pollution and environmental factors [1, 6, 8, 9].

Nevertheless the increase in childlessness, that was seen in Europe since 1980 is partially due to clinical infertility, and partially to important social changes that have strongly modified female and male attitudes toward maternity, paternity and family building [10]. The two main aspects of the problem, infertility and postponed desire to have children are strictly related. In all Europe the mean age of women at birth of first child is 29.1 years in the 2017 Eurostat data [11]. We know, that one of the main factors contributing to female infertility is the advanced female age at conception. The age in which European women begin to desire to have a child is postponed by ten years compared to 1980 data [11]. Partially it is the same also for men [12]. The explanations for this delayed desire for motherhood are numerous: from a social perspective, women's higher level of education and their increasingly relevant role in the field of employment, alongside the possibility of managing their own reproductive life with the use of contraception, accounts for some of the changing attitude [13]. From an institutional point of view, we are witnessing a lack of incentive for creating a family, due to nonexistent welfare policies, supporting motherhood and the family. The female European populations in the vast majority, spend the biological fertile time frame, the years between 20th and 30th, in the pursuit of education, career and personal goals, lacking the financial possibility to create and sustain a family even if wanted.

It is well known that with increasing female age the percentage of ovulatory cycles diminish constantly [14], while the number of aneuploidy in women's gametes rises steadily [12, 15]. Meanwhile the global exposure to infective agents and so the possibility to achieve a sexual transmitted disease, or the exposure to environmental factors increase. Also for men, advanced age is nowadays well known to be related with worse reproductive capacity and negative outcomes [1, 16, 17]. Recent evidence from the literature suggest a worldwide decline in sperm counts over time, possibly due also to environmental effects [16, 18, 19].

Demographic conditions and population size (the bad “relationship” between low fertility rates and population ageing)

The infertility rate in a country is hard to assess. Not all the couples facing infertility will ask help from a fertility clinic, and therefore the numbers are often underestimated. Generally we assume that in Europe 15% of couples are infertile with a range from 6.6% to 16.7% [4].

Over the past decades the demographic trends in Europe have been widely different than in other countries, especially the new developing ones, as we assist in EU to a population decline due to low fertility rates and to population ageing.

An indicator of fertility that can be used and compared across countries is the total fertility rate. This represent the mean number of children that would be born alive to a woman during her life time if she were to pass through her childbearing years conforming to the age-specific fertility rates of a given year [11]. A total fertility rate of 2.1 live births per woman is considered to be the replacement level in developed countries. None of the 28 EU Countries reach this goal today.The mean number of children per woman in Europe was 1.59, in 2017, decreased from the previous year, meanwhile the mean age of women at birth of first child is steadily increasing reaching 29.1 years [11].

In some of the 28 European Countries, during these last years, social policies have been developed to try to support and enhance younger families. In countries like France or Sweden where the Government has realized the real burden of low natality, and therefore has implemented strong social interventions to support young families, the replacement level has been reached in some years and the situation is not so critical [20]. Fertility rates are around 1.9 for the former and 1.8 for the latter [11].

On the other side, countries such as Italy or Germany, where during the last decade nothing has been done to reverse this dramatic trend, the fertility rate reaches the lowest peak of 1.3.

In Italy in particular, the number of births in 2018 reached 439,747 which is the historical minimum recorded by the unity of Italy, about 18,000 born less than the previous year 2017 with a percentage decrease of -4%. The age at first birth is the eldest in Europe (31.1) for women and quite high also for men (33.5) [11].

The fact that life expectancy continues to grow, in all Europe, together with the low fertility rates, reported in the Countries, will determine an unsustainable burden on public pensions and health–care system in the near future.

Could ART application and availability modify the fertility rate in a Country?

The development of assisted reproductive technologies in the last decades has been fundamental in the treatment of infertility and it certainly helped many couples to have children, but cannot reverse the impact of advanced maternal age. We know that the application of ART techniques is steadily increasing worldwide and in particular in Europe reaching around 0.8 million cycles of treatment per year, as reported by the EIM (European IVF Monitoring) ESHRE [21-23].

Analyzing the last data collected by the EIM (European IVF monitoring) in 2015, we can draw a picture of the different European Countries that show different attitudes and policies regarding ART access and availability.

Two are the main indicators of the availability and access to those techniques, one is the number of cycles performed in a given year divided by the number of million fertile women (aged 15-45) and the other one is the percentage of babies born after IVF on the national births [22, 23].

The last EIM dataset could be compared to the fertility rates reported in EUROSTAT statistics [11, 23]. If we look at the table provided in figure 1 in which is shown the mean age at birth of first child with the total fertility rate in each EU Country, we can see that there are countries that maintain a better fertility rate also in the presence of an advanced maternal age (top right quadrant). These Countries are almost the same that in the EIM report have the better access to ART treatments and the highest percentage of babies born after IVF (table 1).

In Countries like Denmark and Sweden, for instance, where the fertility rates are higher than the average EU values, also in the presence of an advanced maternal age, both the indicators of ART availability and access are over the mean values.

In figure 2 the total fertility rate is linked with the number of ART cycles per million fertile women (15-45), utilizing 2015 EUROSTAT and EIM data [11, 23]. This comparison has been useful to underline the importance of single Country's policy also for fertility care.

In Countries like Denmark, Belgium, Sweden and France, with highest fertility rates there is a better access to ART treatments and a better social care for families. ART procedures could certainly help to improve fertility rates but they should be widely offered and must be linked with social economic intervention.

During the last years, another technique, oocyte freezing, has been offered to young women to try to “reverse” the biological clock and extend their reproductive lifespan. This technique offer the possibility to cryopreserve women's own gametes and utilized them later in life. From 2013 thanks to its high efficacy, it is no more labelled as experimental [24-26], and could be considered a good tool to try to postpone motherhood. Unfortunately it cannot guarantee to have a child in the future and could not protect prospect mothers from the risks coming from advanced age ART pregnancies [27, 28].

Conclusions

European Countries should ameliorate the awareness of young generation regarding the “right” (ideal) biological time to have children and the real efficacy of assisted reproductive techniques related to female age, and improve knowledge among doctors [29]. Strong government policies promoting the good attitudes and life skills to maintain a healthy sexual and reproductive life must be in place together with social support for motherhood and family building projects.

Assisted reproduction and fertility preservation techniques through oocyte cryopreservation, could only partially and minimally contribute to the fertility rates of the future population. Women should know that their fertility declines after 32 years of age and that assisted reproduction cannot guarantee a child or compensate the age related fertility decline [30]. Information on prospective parents should stress that with advancing age also male fertility declines and the percentage of abnormalities in the offspring will increase [31, 32]. Implementing strategies to improve knowledge on the reproductive issues could avoid unconscious and unwanted childlessness for future European generations.

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