Desperate would-be mums are risking serious sexual health problems by sleeping with strangers in a bid to get pregnant, fertility experts have warned.

Doctors in Cheshire say a ‘chronic’ shortage of donor sperm has led to a steep rise in the number of unregulated websites and forums where men are offering unprotected sex to help women achieve their dreams of parenthood.

One 6ft 1in tall ‘healthy man’ living in Ellesmere Port described online how he wanted to ‘help someone to start a family’.

He added that he would ‘prefer it to be the natural way’ – referring to natural insemination involving sexual intercourse - as opposed to artificial insemination.

Another advert offered the services of a Chester-based ‘healthy, fit 30-year-old male hoping to help any couple or single women to have their dream’.

Such ads raise concerns that men are targeting vulnerable women for free sex.

Dr Luciano Nardo, of Daresbury-based Reproductive Health Group, said: “For some people, the only way they can realise their dream of having a baby is by relying on donated sperm or eggs.

“This could be for a number of reasons, including the male partner having a low sperm count, or if the woman is single or in a same sex relationship.

“Sadly, we are seeing more and more of these worrying sites and forums popping up where people can both advertise their services and appeal for donors. But it’s a very dangerous game.”

A pregnant woman having a scan.

In the UK, it is against the law to distribute or procure sperm and eggs without a license from the Human Fertilisation and Embryology Authority (HFEA).

The license means clinics are bound by strict rules and guidelines where donors are rigorously tested for medical and genetic conditions. Sperm is also screened and quarantined for six months, to prevent any risk to the health of the mother or the unborn child.

Donors must also disclose any medical conditions running in their family, and are restricted to donating to up to 10 families, to prevent children being born with very high numbers of half siblings.

Dr Luciano Nardo, of Daresbury-based Reproductive Health Group.

Dr Nardo says: “These rules are in place for a reason. Without them, women are exposing themselves to countless risks.

“Not to mention the personal safety issues surrounding meeting and having sex with a stranger.

“Unfortunately, there is a possibility that people may be offering a donation in this way for very unpleasant motives.

“It is extremely concerning to see people offering their services to people desperate to have children – but doing so only on the basis that there will be an element of sexual intercourse.”

The last available figures released in 2013 by the HFEA showed that in 2013 just 74 men registered as sperm donors in the North West. This reflects a national shortage of donor stocks.

In October Britain’s first national sperm bank announced it had given up recruiting for donors after only successfully taking on seven men in 18 months.

A ‘right to know’ introduced in 2005 has previously been blamed for demand outstripping supply.

Since that time, any person conceived through donated reproductive cells can apply for the name, date of birth, and last known address of the donor as soon as they turn 18.

Scouring the internet for donors circumvents the law, but also opens up a whole new range of problems.

Men donating sperm through regulated sperm banks are not legally considered the parent of any offspring.

As a result, they will have no legal obligation towards them, will not be named on the birth certificate, have no say on the upbringing of the child and will not be asked to support the child financially.

Where fresh sperm is donated outside of a licensed clinic, the donor is considered to be the child’s legal father, with all the responsibilities that involves.

“The way people often get around this obvious risk is by using fake names and details, thereby throwing up even more uncertainty and risk,” said Dr Nardo.

Daresbury-based Reproductive Health Group

As well as health and legal risks, Dr Nardo warns of the psychological implications for those involved.

He said: “Making the choice to use donated sperm is not easy. It can be a very emotional process and as such, we always offer counselling with our treatment.

“It is an essential part of what we do and gives the patient the chance to talk through any concerns, and really understand the wider implications of what they are about to do.”