One of the clinics using Cryos sperm is the Morehampton in Donnybrook, Dublin. Last year it helped 84 couples with donated sperm.
According to Mary McNeaney, the co-ordinator, most were in their late 30s and early 40s. Sometimes the men have had cancer and have been sterilised by the treatment, others are in second relationships and have failed to have a vasectomy reversed.
But most simply do not have enough good quality sperm. On average, one in three couples achieve a successful pregnancy - usually on the sixth attempt. Costs vary but a simple insemination costs €250 - a more difficult procedure is nearly €500. The clinic takes the physical characteristics of the couple into account when seeking a donor. Blood group, height, skin colour, eyes of both the couple come into account when seeking a suitable donor.
"Counselling is important," says Ms McNeaney. "It can be very hard for people and if we had someone asking for a blonde haired and blue-eyed baby - when they themselves are dark hair and brown-eyed - we'd need to know why." But genetic information is also important to some couples. "We've had a number of couples who've asked that the donor be screened for the gene that carries cystic fibrosis."
The issue of anonymity is a difficult one for her. Cryos does register donors, so it can trace them if a problem emerges. But the British proposal, that children will be able to trace their biological fathers, is something she fears will deter people from being donors. "Most of these lads are students and doing it because it helps people," she says. "Why would they put their names down so that in 20 years' time someone can find them and say you're my dad!"
She says removing anonymity from donors may cause a shortage, but who's to say whether the children involved will know whether they've come from a donated egg or sperm? "Ninety-five per cent of couples tell nobody about their treatment - many don't even tell us when they become pregnant."