A 25-year-old transsexual man in Barcelona has announced that he is pregnant with twins, prompting debate in Spain about the ethical use of reproductive technology.

Rubén Noé Coronado Jiménez, who is reportedly nine weeks pregnant, interrupted hormone treatments and postponed plans to have a full sex-change operation in order to get pregnant because his 43-year-old girlfriend could no longer have children.

After emailing the 158 fertility clinics in Spain, he found one in Barcelona willing to help him prepare his atrophied uterus for insemination by donated sperm. "I have a right to have a baby," he told reporters. "We are going to be a father, a mother and two children. I don't see the problem."

But the announcement of the unlikely pregnancy - which was trumpeted in Spanish newspapers with photos of a tattooed, unshaven Coronado caressing his barely visible bump - has worried the medical community in Spain. "The intervention for a sex change should be complete, which means the removal of the ovaries," Dr Josep-Luis Ballescà, a gynaecologist at the reproductive andrology unit at the Clinical Hospital of Barcelona, told El País.

He called the pregnancy "technically feasible but not necessarily ethically acceptable". He added: "It is a contradiction. I do not favour it."

Another gender specialist, Dr Iván Mañero, warned of the danger that patients use such pregnancies to "earn money with media exclusives".

Jiménez was born Estefanía Coronado Jiménez in the Andalusian province of Jaén. His female name still appears on his national identity card, allowing him to qualify for fertility treatments and artificial insemination.

He has already taken steps to change his gender on the ID, as more than 1,000 other Spanish transsexuals have done, even though they have not undergone full operations.

He has already had his breasts surgically removed and plans to undergo a sex change operation after the birth in September.

He and his partner, who is nearly blind and sells lottery tickets for an association for the disabled, have already chosen names.

Coronado is not the first transsexual to become pregnant, but is reportedly the first to have twins.

Last June, a 35-year-old American, Thomas Beatie, reportedly became pregnant by insemination at home after nine doctors refused to perform the procedure. He gave birth to a baby girl.

Coronado said: "This is my last chance, I can make use of my body, what I still retain of a woman inside, before the doctors take it from me for ever," he told El Mundo. "My situation is like a person who is born with a third hand. While you have it, you put it to good use. When it gets in the way, you remove it."

Mar Combrolle, president of the Association of Transsexuals of Andalusia, denied Coronado's pregnancy was "a contradiction". She said: "The desire to have a child knows no sex. I think any biological man who wanted a child would give birth if he could." She added that she recognised that not every transsexual would postpone a sex change in order to become pregnant.