London, June 30 (IANS) Mothers who drink alcohol while they are pregnant may be damaging the fertility of their future sons, a new study says.
Doctors in Denmark found that if mothers had drunk 4.5 or more drinks a week while pregnant, then the sperm concentration of their sons, measured about 20 years later, was a third lower in comparison to men who were not exposed to alcohol while in the womb.
A drink was measured as 12 grams of alcohol, which is the equivalent to one 330 ml beer, one small (120 ml) glass of wine or one glass of spirits (40 ml).
Cecilia Ramlau-Hansen, senior researcher and clinical associate professor in epidemiology, Institute of Public Health, University of Aarhus, Denmark, said: ‘Our study shows that there is an association between drinking a moderate amount of alcohol (about four to five drinks a week) during pregnancy and lower sperm concentrations in sons.’
‘It is possible that drinking alcohol during pregnancy has a harmful effect on the foetal semen-producing tissue in the testes – and thereby on semen quality in later life – but our study is the first of its kind, and more research within this area is needed before any causal link can be established or safe drinking limits proposed,’ said Ramlau-Hansen.
Ramlau-Hansen and her colleagues studied 347 sons of 11,980 women with singleton pregnancies who were recruited to the Danish ‘Healthy habits for two’ study between 1984-1987.
Around the 36th week of pregnancy the mothers answered a questionnaire on lifestyles and health. The sons were followed up between 2005-2006, when they were aged between 18-21, and semen and blood samples were collected and analysed.
The researchers divided the sons into four groups, ranging from those who were least exposed to alcohol (their mothers had drunk less than one drink a week) – and this was the reference group against which the other groups were measured – to those whose mothers drank 1-1.5 drinks a week, 2-4 drinks a week, or 4.5 or more drinks per week.
They found that sons of mothers drinking 4.5 or more alcoholic drinks a week had average sperm concentrations of 25 million per millilitre, while the sons who were least exposed to alcohol had sperm concentrations of 40 million/ml.
After adjusting for various factors, they found the sons in the group most exposed to alcohol had an average sperm concentration that was approximately 32 percent lower than that in the least exposed group, said a release of University of Aarhus.
The World Health Organisation defines a ‘normal’ level of sperm concentration as being approximately 20 million/ml or more.
These findings were presented at the 26th annual meeting of the European Society of Human Reproduction and Embryology in Rome Tuesday.
