A new large Copenhagen study reveals that the semen quality of young Danish males has improved slightly over the last 15 years. However, the semen quality of contemporary males is still disturbingly low when comparing with Copenhagen males in 1940.
Each year throughout the last 15 years, researchers at Rigshospitalet's Department of Growth and Reproduction have been collecting and analysing semen samples from around 300 young Danish males. So far a total of 5,000 men have taken part in this study, which makes it the largest of its kind. In hard figures, the study shows that average sperm concentration went up from 43 million/mL in 1996-2000 to 48 million/mL in 2006-2010. Less than one in four young Danes has optimal semen quality, and the semen quality of a large minority is so poor they will have difficulties making a woman pregnant."Although we see a slight rise, only 23% of the young men had optimal semen quality. In fact, the semen quality of 27% of the men was so poor, it will probably take these men longer to make their partner pregnant. Furthermore, for 15% of the men, semen quality was so poor, they are likely to need fertility treatment in order to conceive," concluded Dr Niels Jørgensen, who is heading the study.
Results from the study were also compared with historical data from men living in Copenhagen in the 1940s. "The historical data stem from men who were unable to conceive with their spouse, and who are therefore presumed to have had poorer semen quality than the general male population in 1940. Nonetheless, the semen quality of the men who had reproductive problems in Copenhagen in the 1940s is still significantly better than that of young Danish males today," said Niels Jørgensen.
The new study is being published exactly 20 years after a research group at Rigshospitalet published an article in 1992, which stirred considerable debate. This article, which indicated with good probability that semen quality had been falling over a period of 50 years, became the launch of a new era for research into the reproductive health of men. According to Niels Jørgensen, the study which has now been released was commenced with a view to address the concerns arising from the 1992 article.
Reference:Human semen quality in the new millennium: a prospective cross-sectional population-based study of 4867 men
Contact:Dr Niels Jørgensen, head of the studyDept. of Growth and Reproduction, RigshospitaletTelephone: + 45 35 45 50 60 or +45 35 45 50 85