A Hong Kong court has sided with a lesbian couple who argued that both women should have parental status over their child born via reciprocal in vitro fertilisation (RIVF), a ruling hailed as a win for the LGBTQ community.

The medical procedure of reciprocal in vitro fertilisation (RIVF) allows two women to share in the process of childbearing and is credited with helping same-sex couples start families.

Two women who took part in RIVF launched a legal challenge last year after the Hong Kong government recognised only one of them as the mother of their son, citing existing family laws.

On Friday, judge Queeny Au-Yeung at the court of first instance ruled that the government’s non-recognition was a form of discrimination against the couple’s son.

Their child was “discriminated as to his birth in the sense that, unlike other children, he does not have a co-parent, genetically linked to him,” the judge wrote in her ruling.

The court declared that the woman initially denied legal status should be recognised as a “parent at common law”, saying the move would align her legal status with reality.

“The court should be astute to the changing world where people build families in different manners other than through a married or heterosexual relationship,” the judge added.

In RIVF, a lesbian couple can jointly take part in childbearing as one woman’s egg, fertilised externally with the aid of a sperm donor, is transferred to the other woman who carries the pregnancy to term.

The procedure was introduced in the late 2000s and can now be performed without restriction in more than a dozen European countries, according to an academic survey.

As Hong Kong does not recognise same-sex marriages, the two women in the case — who were granted anonymity by the court — were married and underwent RIVF in South Africa.

Lawyer Evelyn Tsao, who represented one of the women, called the ruling “one giant step for the rainbow families in our LGBTQ community”.

“For the first time, the court expressly states that children of same-sex couples are discriminated by the current legislation,” Ms. Tsao told AFP.

Barrister Azan Marwah, one of the lawyers who argued the case in court, said on social media that the ruling was a first in the common law world.

The Department of Justice told AFP it was “studying the judgment in detail and considering the way forward”.

Earlier this month, Hong Kong’s top court ruled against same-sex marriage but ordered the government to provide an “alternative framework”, such as civil unions, to protect the rights of homosexual couples.