Earlier this year, 37-year-old Martha fulfilled a lifelong dream -- she became a mother. Martha is clearly delighted with her three-month-old daughter Kate, and feels lucky that Kate has inherited her uncle's smile and her grandfather's eyes. But there's a part of her baby that Martha will never know. Except for some medical details, neither mother nor daughter will ever know anything about Kate's father because Kate was conceived using anonymous donor sperm.

"For me the urge to be a mother was greater even than the urge to be a wife or partner," says Martha, "and I didn't want to let the opportunity to have a baby pass me by while I was waiting for Mr Right. I know single women in their forties and fifties and they have told me they regret not having kids. I didn't want that to happen to me. I wasn't going out with anyone, and I knew the later I left it the more difficult it could be to have a baby, so I started trying to conceive using donor sperm when I was 34."

Having a baby using donor sperm wasn't easy and it took Martha €30,000 and three years to achieve her goal. When she started her inquiries she could not find anyone offering donor insemination in Ireland and travelled to the Harvey Clinic in London for intrauterine insemination (IUID) and in vitro fertilisation (IVF) using donor sperm.

Now there are two private clinics in Ireland offering the service, and last year Martha had successful IVF using donor sperm at the Kilkenny Clinic.

According to a spokesperson for the clinic, stories like Martha's are increasingly common. Dr Martine Millett Johnson, Medical Director of the Kilkenny Clinic, says they get queries from single women every day.

"A lot of women out there haven't met the right person and feel the clock is ticking. There are now technologies available to help people in that position, like IUID with sperm donation and egg freezing. The single women who are looking for these treatments are mostly professional women who are developing their career, furthering their education, buying their own house and want to be financially secure."

The donor sperm used comes mostly from Denmark and England, and donors usually choose to remain anonymous. IUID costs about €2,000, but with a success rate of about 11pc, repeat procedures can cause the cost to climb. If IUID isn't successful then IVF using donor sperm is available for about €6,000, and again that procedure may need to be repeated.

At the moment there is no Irish legislation covering assisted reproduction, but that's expected to change in coming years. Britain recently outlawed anonymous sperm and egg donation and in 2005 an Irish Commission on Assisted Human Reproduction recommended that children born of such treatments should know the identity of the donor.

For her part, Martha intends to tell Kate the truth about her origins as soon as she is old enough to understand.

"I will tell her as soon as it's possible, in terms she can understand. I think honesty is the best policy. If someone says in the schoolyard that she's a donor baby, I don't want her to be shocked. I want her to know and to be able to turn around and say, 'so what?'. I know some people say it's selfish to do this, but you can have a baby within marriage and both be enemies within a year. I think the fact that she is loved and wanted so much will overcome the fact that she won't have a dad."

In some regards, Australian-born Joanna Rose is similar to Martha. She is 35, single, and would very much like to have a family, but Joanna would never consider having a baby through IUID. Joanna is herself a child of donor sperm and strongly disagrees with the procedure.

"If you're not even prepared to look someone in the eye and have sex with them then you definitely shouldn't be trying to have a baby with them. One of the worst things you can do to a child is to block them from forming relationships with half their natural family. It's a human need to know where you come from and there's a real sense of loss in people who are raised without their genetic kin.

"For me it has been a terrible burden. I am still fighting for the right to find out information about where I come from and even now I cannot confirm who my natural father is. It's very painful for me to know I'm intentionally blocked off from half of my identity."

Joanna argues that open adoption and fostering are more responsible and child-centred options than using donor sperm. 'People want to be a genetic parent so they choose donor sperm instead of adoption or fostering.

"The irony is that in fulfilling their own need to be a genetic parent they disregard their child's need for the other genetic parent.

'One of the key things of being a parent is putting your child's interests first. For people who want to be parents, there are plenty of children in the world who are in care and need help."

For single people who share Joanna's concerns, overseas adoption is a popular option. The International Adoption Association (IAA) estimates that about a fifth of their membership is now made up of single adoptive parents or those trying to become single adoptive parents.

"Most of the single people who adopt from overseas are women, mainly from early thirties to late forties", says IAA chief executive, Grace Kelly.

"Often they have not met their life partner but have a very strong desire to be a parent and decide that adoption is the best route for them. There would also be a percentage of younger women who want to give a child a better life and are doing it from a humanitarian perspective."

The adoption process can take several years and the IAA advises people who are considering overseas adoption to apply as soon as possible -- the wait for a preparation course alone can take up to four years. That's followed by several assessments and visits by the HSE after which the successful applicant is forwarded to the Adoption Board for a declaration of suitability.

The applicant then has to organise the adoption themselves in conjunction with their country of choice. When fees, flights, accommodation and solicitors are all added up the process can be expensive. Costs vary depending on the country of adoption but for a popular country like Vietnam the estimate is about €15,000.

Judging by the number of queries to fertility clinics and adoption organisations there are currently several hundred single Irish women pursuing motherhood without any male involvement.

One popular Irish parenting website features messages from several older single women grappling with the fact that they may never have a conventional family and trying to decide between donor sperm, adoption, or acceptance of childlessness.

One single woman is leaning towards IUID, but is nervous about the repercussions. "The issue I have is that this isn't just about me, it's about my child," she writes. "I'm so worried that he or she would suffer as a result of the way in which I chose to conceive. Is this a terribly selfish thing to do? Should I risk waiting for Mr Right (or any Mr) to arrive and conceive that way instead?"

Another single woman is looking for advice on what's involved in overseas adoption and whether she'd be likely to get approval. Others speculate about the benefits of egg freezing, a service that is due to be available in Ireland through the Sims clinic later this year.

Egg freezing will make it possible to search for a partner or pursue a career without the added worry of declining fertility.

But with egg freezing comes the prospect of Irish women deferring motherhood into their 40s and beyond, and that leads to another host of difficult medical and ethical questions.

Some names have been changed

Maria del Carmen Bousada de Lara is the world's oldest mother --- and single to boot.

In December 2006, shortly before her 67th birthday, she gave birth to twin boys after undergoing IVF in a private fertility clinic in Latin America.

The first-time mum later admitted lying to the doctors about her age, having claimed to be 55.

She said that she had never before had the opportunity to have children, and had never met the right man. She decided to have a baby after her mother, for whom she cared in old age, died in 2005.

Previously Romanian Adriana Iliescu held the title of 'world's oldest mum'after having a baby girl in January 2005 at the age of 66.

Iliescu underwent IVF using anonymous donor sperm and an anonymous donor egg.

She had previously been given hormone treatments to reverse the menopause and underwent 10 years of fertility treatment before having a successful pregnancy.

- Anna Murphy