When these results were correlated with the earlier fetal growth assessments, being consistently small in utero was associated with a significantly greater chance of having a sperm assessment within the lowest quartile of all the men assessed; men with good intrauterine growth were less likely to be in this lowest quartile of sperm production in adulthood. Being exposed to their mothers' smoking (18.6% of men) was also associated with lower sperm production.
Increased testicular volume was correlated with childhood growth, height and total lean body mass.
Commenting on the results, Professor Hart proposed that poor fetal growth, exposure to maternal smoking, poor childhood growth patterns, increased fat deposition in adolescence, and smoking and drug use in adulthood may ultimately lead to reduced semen parameters. Hence, public health measures to address these influences may help to reduce these risks in the future. Professor Hart said: "The main message from our study is that to reach adulthood with the best possible testicular function a man should not be exposed to his mother's smoking, should have good fetal growth and, in childhood and through adolescence, should be 'appropriately grown' - that is, neither underweight nor overweight, and as an adult should not smoke or take drugs."
On the question of environmental "endocrine disruptors" as an explanation for a decline in
semen quality, Professor Hart added: "The extent of the risk posed by environmental endocrine
disrupters is still unclear, but some researchers do attribute the perceived decline in sperm
counts to these chemicals within the environment. We do not have any evidence to suggest
such a link in our study, but we do intend to measure the fetal exposure to endocrine
disrupting chemicals from maternal blood that was stored in 1990, prior t
|Contact: Christine Bauquis|
European Society of Human Reproduction and Embryology