The same-sex partner of Serbian Prime Minister Ana Brnabic has given birth in what is believed to be a first for a world leader.

Ms Brnabic’s office announced the delivery on Wednesday and said that both the baby boy, reportedly named Igor, and mother Milica Djurdjic are “doing fine.”

“Ana Brnabic is one of the first prime ministers whose partner has given birth while in office ... and the first in the world in a same-sex couple,” her office said in a short statement, according to AFP.

When Ms Brnabic became the nation’s first ever female and gay prime minister in 2017, it was welcomed by western officials as a sign of progress in a deeply conservative Balkan country, where homophobia is common.

Serbia has not yet recognised gay marriage and the head of the country’s orthodox church has compared homosexuality to incest. Same-sex couples are also barred from adopting children.

Hundreds held after Serbian extremists storm Gay Pride march Show all 3 1 /3 Hundreds held after Serbian extremists storm Gay Pride march Hundreds held after Serbian extremists storm Gay Pride march A riot policeman removes his helmet after being injured in clashes with protesters in Belgrade MARKO DJURICA/REUTERS Hundreds held after Serbian extremists storm Gay Pride march A woman at a rally to protest against the Gay Pride march holds a religious icon REUTERS Hundreds held after Serbian extremists storm Gay Pride march A boy at a nationalist rally against the Gay Pride march REUTERS

She has been criticised within Serbia both on the basis of her gender and sexuality and because of her support for the populist conservative government of Aleksandar Vucic.

While Ms Brnabic had declined to support a draft proposal to push for the legalisation of same-sex unions in 2016, she has since joined hundreds of marchers at an LGBT pride event.

"The government is here for all citizens and will secure the respect of rights for all citizens,” she said at one such demonstration in September 2017.

“We want to send a signal that diversity makes our society stronger, that together we can do more.”

Ms Brnabic, a businesswoman who holds a master’s degree from the University of Hull in the UK, was previously the elected minister of public administration and local self-government.