**2.6 Advanced paternal age**

There is no clear definition ofAdvanced paternal age. Studies have defined this age as between 35 and 50 years with a classification in the age range of 5 years [17]. A meta-analysis of 90 studies involving 93839 participants stated that sperm volume, total sperm count, normal sperm morphology, and progressive sperm motility decreased with age and sperm DNA fragmentation increased with age. However, sperm concentration was not significantly associated with increasing age of men [18].
