Trends in delayed onset of fertility among men

It is a common saying that men can have children at high ages. While many studies have discussed consequences for the child of increasing maternal age, few studies have dealt with the impact of paternal age at conception on fetal survival or child morbidity. Recently, though, studies have demonstrated that age of the father is linked to some chromosomal abnormalities, the rate of single nucleotide mutations and to increases in sperm structural abnormalities. During the last 30 years paternal age at first child has increased in Denmark and men are about two years older than women when they have their first child. We analyse socio-demographic characteristics of men (living with a women) who has their first child after age 40 during in the period 1980-2001 in Denmark to elucidate whether these old first-time fathers increase in proportion and constitutes an increasingly selective social group and which consequences might follow.