Final answer:
The best age for men to have children is not explicitly determined by D'Onofrio et al's research; it rather suggests a balance between biological factors and personal readiness, influenced by changing societal trends and attitudes towards family and sexuality.
Step-by-step explanation:
From D'Onofrio et al's research and understanding of the factors affecting childbearing decisions, one could conclude that the best age for men to have children is not specifically defined. Rather, it suggests that the choice is influenced by a range of factors including societal trends, personal circumstances, and biological considerations.
The statistics indicate that parenting roles are changing over generations as seen with different lifestyles and attitudes. Additionally, the assertion that the risk of having a child with Down syndrome increases with maternal age, particularly after age 35, can imply that becoming parents at a younger age might be beneficial in terms of genetic risks. However, other research suggests the importance of socioeconomic stability, which can be more common in older parents. Therefore, the optimal age for fatherhood is likely a balance between biological factors and personal readiness for parenthood. It is also essential to note the societal changes in perceptions of family and sexuality, reflected in modern attitudes towards marriage and parenthood.