L. Gandini

Myth and reality of the decline in semen quality : An example of the relativity of data interpretation

Many hypotheses have been put forward to explain a suspected decline in semen quality. Up to now many sources of data were used but conflicting results are present in the literature. To study whether modifications of sperm parameters actually exist we used data from two groups of patients checked and two small groups of sperm bank donors selected at the beginning ’80s and ’90s. We tried to reduce bias to a minimum: all the semen analyses were carried out by the same biologist, using the same methods, groups were clinically evaluated by the same andrological team, the study groups were homogeneous for age, geographic-ethnic origin, residence, monthly-seasonal distribution and abstinence period. Comparing patients from the ’80s and the ’90s, sperm concentration and motility showed a significant reduction. Furthermore, the decrease in concentration and motility was mainly due to the higher age classes. In donors, no decline was observed. These results seem to indicate that sperm donors remain unaffected, while patients with lower levels of semen quality are experiencing a real decline. Unfortunately, many confounding variables, analyzed in detail in this review, still remain despite efforts at standardization.

Esame del liquido seminale: il nuovo manuale WHO 2010

SommarioLo spermiogramma rappresenta l’indagine di laboratorio di primo livello nell’iter diagnostico del maschio infertile. Èxa0un’analisi specialistica che necessita di un laboratorio dedicato e di una formazione specifica in seminologia. È importante sottolineare che la valutazione seminale deve essere basata su criteri scientifici e metodologici condivisi. Questo è reso possibile dall’utilizzo dell’ultima edizione del Manuale WHO. In tal modo, l’esame del liquido seminale potrà rappresentare uno strumento utile all’andrologo per una corretta diagnosi e un’adeguata impostazione terapeutica.

Myth and reality of the decline in semen quality

Many hormonal and non hormonal hypotheses have been put forward to explain a suspected decline in semen quality. We report on sperm parameter variation from the beginning of the eighties and the nineties in patients requesting an andrological clinical examination (1172 and 1393 respectively) and sperm bank donors selected by the same andrologists (17 and 21 donors, with 170 and 227 semen analyses respectively). We reduced bias to a minimum: all the semen analyses were carried out by the same biologist, using the same methods, the study groups were homogeneous for age, geographic-ethnic origin, residence, monthly-seasonal distribution and abstinence period. Comparing patients from the 80s and the 90s, sperm concentration and motility showed a significant reduction. Furthermore, the decrease in concentration was mainly due to the age classes 26-30 and 31-35. The decline in motility was mainly due to the age class over 40 years. In donors, slight variations without a biological impact were observed. Our results indicate that subjects with higher levels of sperm production remain unaffected, while those with medium and lower levels are experiencing a real decline. This could mean that a selection is taking place in our country in favour of young, healthy, and highly fertile men.