Not unlike a fine wine, experts are claiming sperm may be of a higher caliber with age.

A new study suggests that when looking to get pregnant via donor sperm a women's best bet may be to go with sperm from a man in his 40s. The study claims that women, when going the donor sperm route, may be more likely to get pregnant if the man is over 40 rather than under that age.

In what researchers say is the first major study to investigate the effect of male age on fertility treatment using donor sperm, it was discovered that for sperm donors aged under 20, the birth rate using IVF techniques was 28.3 percent. When the age of the donors was 41-45, the birth rate rose to 30.4 percent. With regard to donor insemination patients, the birth rate was 9.7 percent when the donor was aged under 20 and rose 12 percent when the donor age was 41-45.

The research was conducted by scientists at the Newcastle Fertility Centre at Life in Newcastle, UK, as they looked at 40,000 treatment cycles involving donor sperm between 1991 and 2012 from the database of the Human Fertilization and Embryology Authority (HFEA), well-known UK fertility experts.

"No decline in live births was observed with the increasing age of men, that's the take home message from a large national database. It's sperm quality rather than male age that matters," explained Dr. Meenakshi Choudhary, from the Newcastle Fertility Centre at Life, Newcastle, the lead researcher on the study. "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."

There has been a shortage of donor sperm in the UK for couples desperate to start a family and HFEA's guidelines currently recommend clinics don't use sperm donors over 45 and current guidelines for doctors suggest 40 as the cut-off point.

This, coupled with a recent increase in demand for sperm donations due to more single women deciding they want to start families, has created a bit of crisis in the UK. The findings in the Newcastle Fertility Centre at Life study are suggesting it may time to change these guidelines. Approximately 25 percent of the donor sperm currently being used in British fertility clinics comes from abroad.

The controversy over raising the donor sperm age limit centers around concerns that using sperm from older donors has been linked to greater risk of miscarriage, pregnancy loss and birth defects.

Study results were discussed July 1 at the European Society of Human Reproduction and Embryology's annual meeting in Germany.