HELSINKI (AFP) - A Finnish woman who underwent hormonal therapy has become the nation's first transgender man to give birth, local media said on Wednesday (April 4), triggering controversy as laws require infertility to change gender.

"The baby weighed nearly four kilogrammes and was 53 centimetres in length (at birth)," the transgender man, whose name was not revealed to protect the family's privacy, told Finnish news outlet Lannen Media a fortnight after the birth.

The man, who is in his 30s, legally changed his gender from a woman in 2015 after years of testosterone therapy.

But he decided to cancel sex change surgery, to complete his male physical transition, before trying to get pregnant with his husband.

Under Finnish law for hormonal therapy, a person is required to prove they are "infertile" in order to change their legal gender from female to male.

In practice, Finnish medical units deem their transgender patients infertile when testosterone therapy has continued for a prolonged period.

But fertility can sometimes return if hormonal therapy is put on hold.

This case is exceptional because the couple, who live in the Helsinki region, decided to suspend hormonal treatment and after a year the man's period returned.

"Do I want the society to dictate what I can do with my body and my life? Nothing can stop me. I'm a free man," the man said in an earlier interview with Finland's Helsingin Sanomat newspaper while still pregnant.

CALL HIM 'DADDY'

Finland is the only remaining Nordic country to require infertility from citizens who want to change their legal gender, prompting sharp criticism from human rights organisations in recent years.

Authorities have, however, taken a flexible attitude towards the first male pregnancy, granting the transgender man a full-length paternity leave.

Doctors were uncertain how the previous hormonal treatment would affect the pregnancy, but everything went normally, with the birth just overdue.

"The last couple of weeks were quite painful and I began to run out of patience. But the birth itself went really well," the man told Lannen Media.

He said he wants the baby, whose gender was not revealed, to call him "daddy".

The man's husband was born a male but says he doesn't want to identify himself with either of the sexes.

The couple said they plan to raise the child in a gender-neutral manner.

The birth is not the first of its kind in the world, but transgender pregnancies are still rare.

In 2008, a US man who was born a woman before undergoing gender realignment surgery gave birth to a baby girl.

Thomas Beatie, who is legally male but decided to keep his female sex organs during chest reconstruction surgery and testosterone therapy, gave birth to two more children over the next two years, US media reported.