UK scientists have stated that females using donor sperm are more likely to become pregnant is the donor is over the age of 40.
The first large study to investigate the effect of the donor’s age on fertility treatment found no great difference in the live baby rate linked to the man’s age. However, it was found that women were more likely to become pregnant if the donor was aged over 40. This may be due to him already having proved fertility by having his own family.
The current guidelines in the UK suggest that males over the age of 40 not be accepted as donors. Sperm donations from older men were previously linked to greater risks of birth defects and miscarriage.
In view of the new findings, experts have asked for the guidelines to be reviewed in a bid to east the donor shortage.
The figures were obtained from a UK fertility watchdog database. Scientists reviewed 40000 treatment cycles linked to donor sperm between 1991 and 2012.
It was found that for sperm donor under the age of 20, the birth rate using IVF methods was 28.3%, with an increase to 30.4% when the donors were aged 41 to 45 years. In donor insemination patients, the rate 9.7% if the donor was under the age of 20, and 12% from donors aged between 41 and 45.
One of the study leaders, Dr Meenakshi Choudhary, from the Newcastle Fertility Centre, stated that the quality of the sperm is more important than the donor’s age. He said that the study indicated that the selection of sperm donors with good sperm quality was excellent, hence there was no difference in the live birth rate regardless of the age of the donors.
She added that women were less likely to become pregnant when using sperm from younger donors as they have not yet proven fertility. She stated that advanced paternal age has been linked to long-term disorders in the babies, but the evidence on hand is limited.
The code of practice from the HFEA advises clinics not to accept and use sperm from males aged over 45. The cut-off age according to the guidelines is 40. Older men were included in the study as the data went back beyond the recent guideline date.
Experts have raised concerns about the shortage of donor sperm and eggs. Some of them have blamed the change in UK law during 2005 when it was stated that sperm donors need to reveal their true identities to children born to them when that child reaches the age of 18.
Although there have been calls for the donor age limits to be increased, Professor Allan Pacey, the chairman of the British Fertility Society, has stated that there is a small, but detectable, increase in disorders of children born to sperm donors who are older.
He stated that the study does not provide answers about the children’s health.
Image Credit: Stéphane Moussie