Men who are diagnosed with inflammatory arthritis before the age of 40 are less likely to want children and more likely to be unable to have them.
According to an observational study in the Netherlands, while men with these diagnoses were more likely to be voluntarily childless, they were also significantly more likely to be involuntarily childless when adjusting for factors including current age, educational attainment, history of cardiovascular disease and partner's fertility, suggesting that inflammatory arthritis or its treatments could impact fertility. Researchers also showed that there was a greater impact on fecundity for men diagnosed before the age of 30, compared to those diagnosed between the ages of 31-40, which is when most fathers have their children in the Netherlands, and there was no impact for men diagnosed after the age of 40.
'The difference between the desired and final number of children was significantly larger in men diagnosed before and during the reproductive age, indicating that the lower fertility rates are primarily affected by reduced fertility potential and not by a reduced desire for parenthood,' wrote the researchers. Results from the study were published in the British Medical Journal's Annals of the Rheumatic Diseases.
The team sent out questionnaires to 1841 men between September 2019 and January 2021. They only included men who had completed their families and asked about age at diagnosis, size of desired family, number of children they had and how long it had taken them to conceive, among other questions about their demographic, medical and fertility history. Of the 1841 men sent questionnaires, 628 responded.
On average, men diagnosed with these conditions prior to their 30th birthdays had 1.32 children, compared with 1.56 for those diagnosed between ages 31 and 40 and 1.88 for those diagnosed when they were age 41 years or older. Furthermore, the percentage of childless men was higher among those diagnosed early. Of those diagnosed before age 30, 34 per cent remained childless compared to between 20-25 percent of all men in the Netherlands. For those diagnosed between age 31 and 40, 27 percent remained childless, and those diagnosed over the age of 40, 17 percent had no children. With further investigation, it was shown that 12 percent of those diagnosed when younger identified as 'involuntarily childless', compared with 10 percent and 4 percent in the two older groups, according to the researchers.
There are some plausible biological explanations for the associations found, given that reduced sperm production and poor sperm quality are common side effects associated with many of the medications used to treat inflammatory arthritis. Proteins believed to be involved in the development of inflammatory arthritis, including tumour necrosis factor, are also involved in testicular stability and sperm production.
The authors commented that more research was urgently needed to improve the quality of care for men with this diagnosis and their desire for parenthood.