BioNews reporting from ESHRE conference, Madrid:
Abstaining from sex does not enhance a man's fertility and may lower the chances of a successful conception for couples undergoing fertility treatment, according to new research presented at the annual conference of the European Society of Human Reproduction and Embryology (ESHRE) in Madrid last week.
Fertility experts at the Soroka and Ben-Gurion Universities in Israel looked at sperm samples from around 6,000 men who had abstained from sex for up to two weeks, and found that the quality of the sperm declined after four days abstinence in men with normal sperm counts, and sooner in men with low sperm counts. The findings contradict current World Health Organisation guidelines, which recommend abstinence of between two and seven days before collecting semen for fertility treatment.
The researchers tested more than 7,200 semen samples from 6000 men who had abstained from sex for between two days and two weeks, 4,500 of which had normal sperm counts, while the remainder had a reduced sperm count. They found that in men with normal sperm counts, the proportion of healthy, strong-swimming (motile) sperm rose to a peak after four days of abstinence, before starting to drop. But in men with a low sperm count, the proportion of motile sperm fell after just two days, suggesting that any benefit to fertility gained by boosting the volume of semen following abstinence is cancelled out by a decline in sperm quality.
Lynn Fraser, Chair of ESHRE's international scientific committee, said the results made good biological sense, adding that most men with low sperm counts have testes that are not producing sperm at full capacity and, when numbers are low, the quality is low. 'That means that if you abstain from sex for a long time, you'll be ejaculating sperm that are old and necrotic', she explained.
'Our data challenge the role of abstinence in male infertility treatments' said team leader Elahu Levitas, saying that the results were most relevant for patients undergoing intrauterine insemination, for which the best quality sperm was needed. 'For these patients we recommend minimal abstinence - ideally no more than two days' he advised.