Looking at almost 40,000 sperm donations in the UK, researchers found that women were just as likely to have a baby using sperm from 40-year-old donors as that from younger men.
The study found that for women under 34, the chance of having a baby stayed at around 30 percent for those using IVF, and around ten to 12 percent for those using donor insemination, regardless of the age of the sperm donor.
Previous studies have found that children with older fathers are more likely to have birth defects and develop conditions like autism and schizophrenia (see BioNews 318, 652, and 744). But this study focuses on sperm donors, who must pass rigorous health checks before they are allowed to donate.
'Our study shows that we are good at selecting the right sperm donors with the right sperm quality – and that's why we found no difference in live birth rate despite the increasing age of sperm donors', said Dr Choudhary.
Dr Choudhary's team began to study the effect of sperm donor age when they noticed that the average age of donors shot up from 26 to 35 once a law was passed meaning sperm donors could no longer remain anonymous in 2005.
In the UK, the Human Fertilisation and Embryology Authority recommends that sperm donors should be under 41 years of age, while the upper limit in Australia is 45. The European Society of Human Reproduction and Embryology, at whose annual conference the results were reported, recommends that sperm donors are under 50 years old.
Dr Allan Pacey, senior lecturer in andrology at the University of Sheffield, said that the maximum sperm donor age limit in the UK had been set because of worries to health of any resulting children, and that this was still an issue. 'I would be worried about raising the age limit for sperm donors to 45 because of the possible effects on the health of children', he said.
Dr Pacey estimated that only five out of every 100 men who applied to be a sperm donor would make it past the medical tests required. But he suggested that as the need for more sperm donors grows, clinics' standards may be dropping.
'We are selecting on the basis of sperm quality, and I hope people continue to do that. I get little whispers around the place, that as the pressure to recruit donors is increasing, because we've got so few, people are not adhering to the sperm quality [guidelines], and that is a worry', he said.