[Catamnestic study about the fertility of the man (author's transl)].

Collective investigations of fertility in childless married couples were carried out in 9 andrological health centres of the GDR. Analysis of 1937 spermatograms in comparison to fertility after 1 to 2 years shows: (1) Fertility decreases significantly at sperm density nearly 10 million per ml. (2) Motility below 60 per cent caused reduced fertility.