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'The Snip' may have irreversible effects on sperm
31st March 2004
Scientists call for more research into the long-term effects of
vasectomy, as results revealed today1 suggest that the effects of
‘the snip’ might not be as “reversible”
as previously thought.
Work done at Queen’s University Belfast on testicular biopsies
shows that men who had a vasectomy more than 10 years ago have a
much lower sperm count than non-vasectomized fertile men, and that
ICSI pregnancy success rates using sperm from these men were more
than 50% lower.
Researchers from Reproductive Medicine2 tested 21 men who had vasectomies
for contraception after having children. They found that their sperm
count was about three times lower than that of the 39 non-vasectomised
fertile men assessed, at 3.6 million sperm per gram of biopsy tissue
compared to 11.2 sperm per gram.
Analysing the biopsies they discovered that the number of Sertoli
cells – which nourish the sperm through their development
in the testis – was normal in the vasectomised individuals.
However, the numbers of developing sperm (spermatids) were significantly
reduced.
More alarmingly, they found that couples undergoing fertility treatment
where the male had been vasectomised (and reversal had failed) were
less than half as likely to get pregnant as couples with other infertility
problems. However, only 17 couples post-vasectomy and 37 other infertile
couples have been assessed in this part of the research. A larger
multicentre study is required to elucidate these findings.
Dr Carmel McVicar, who presents the work today, said ‘We
did not expect to see this reduction in sperm count or pregnancy
due to previous vasectomy and ongoing studies are attempting to
decipher the reasons for it.’
‘In the past, a vasectomy was for life. Now men attend our
clinic every week wanting to have a second family with a new partner.
Men who are considering vasectomy certainly need to think very carefully
about the long-term consequences to their future fertility.’
Notes for Editors
1The effects of obstruction on spermatogenesis is presented
at The Annual British Fertility Society Meeting 2004 on Wednesday
31st March 2004, in Cheltenham, UK
2CM McVicar*, DA O’Neill#, N McClure*, SJ McCullough#,
LH Dalzell* & SEM Lewis* from *School of Medicine, Obs &
Gyn, and #Anatomy, Queen’s University Belfast, Belfast, Northern
Ireland, UK
The British Fertility Society is a national multidisciplinary organisation
representing professionals practising in the field of reproductive
medicine. www.fertility.org.uk
For more information: please contact the British Fertility Society press office
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