Epidemiology of male infertility.
Infertility is largely and unfairly thought to affect women. It is the woman that gets pregnant, or not in some cases, and it is the woman who often undergoes many of the infertility-related treatments. When a couple embarks on the in vitro fertilization (IVF) journey, it is the woman who often experiences repeated, and sometimes invasive, procedures and investigations. Throughout IVF, it’s well known that women are treated with prolonged hormonal stimulation, while the man’s role in the treatment process is commonly limited to providing a sperm sample.
When a couple has trouble conceiving, it is often assumed that the issues lie with the female partner. However, male infertility plays a role in many cases. This woman-centred view of human fertility not only presents a psychological and clinical burden for women, but it has also led to men being largely absent from public conversations around infertility. Those men who seek support may be reluctant to open up about their infertility, at risk of being stigmatized or shamed.
So, what can men do? In the era of “Doctor Google”, there is a lot of information available, but it can be hard to decipher reliable advice from fake news. In Europe, the average number of births decreased from the 1960s to the mid-1990s, with a steady plateau over the last twenty years. In 2018, the European Commission reported that on average women have 1.5 children, which is significantly lower than 2.1, the level required to maintain the population size. Among the EU countries, France reported the highest fertility rates in 2019, with 1.86 births per woman, followed by Romania, at 1.77 and Ireland, Sweden and Czechia all with 1.71. By contrast, the lowest fertility rates in 2019 were recorded in Malta (1.14 live births per woman), Spain (1.23 live births per woman), Italy (1.27 live births per woman), Cyprus (1.33 live births per woman), Greece and Luxembourg (both 1.34).
Moreover, couples are also on average giving birth to their children later in life, with latest reports showing that the mean women’s age at childbirth was 30.8 years. These numbers highlight the profound changes occurring within modern society. Couples are facing fertility issues at a progressively greater age which explains an increase in the total numbers of couples struggling with infertility at any given time. Infertility within a couple is defined as the inability of a sexually active, non-contracepting couple to become pregnant in one year and is believed to affect at least one in every six young couples. It is estimated that the cause of infertility can be explained by issues relating to the female partner in 38% of cases, and the male partner in 20% of the time. It is thought that 27% of cases are believed to be due to both partners. This means that despite the impressive improvements in human reproduction diagnostics of recent years, 15% of infertile couples remain without a specific diagnosed cause for their condition. As with female infertility, male infertility isn’t anyone’s “fault”. However, in light of these statistics we should remember that in up to 50% of cases in which couples can’t have babies naturally, the male partner could be contributing towards the underlying cause of infertility.
The list of potential causes of male infertility is exhaustive, ranging from issues with testicular function, to hormone dysregulation. The most common condition detectable in men with infertility is a reduced sperm count. However, in more than 20% of infertile men, the semen analysis is normal, and a definite diagnosis is therefore unclear.
Daniele Santi MD, PhD Assistant Professor in Endocrinology Unit of Endocrinology Department of Biomedical, Metabolic and Neural Science University of Modena and Reggio Emilia
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