WELLINGTON, New Zealand — Prime Minister Jacinda Ardern of New Zealand gave birth to her first child, a girl, on Thursday, making her the first world leader in almost three decades to give birth while in office.
Ms. Ardern, who announced the birth on social media, did not say whether a name had been chosen yet.
Ms. Ardern, 37, whose youth and surprise rise to power have made her a global celebrity, delivered her baby in Auckland at the country’s largest public hospital. Once she entered the hospital on Thursday, Deputy Prime Minister Winston Peters officially assumed the role of acting prime minister.
“Welcome to our village wee one,” Ms. Ardern posted on Instagram. “Feeling very lucky to have a healthy baby girl that arrived at 4.45pm weighing 3.31kg (7.3lb),” she wrote. Thank you so much for your best wishes and your kindness.”
Ms. Ardern will take six weeks of parental leave before returning to work, at which point her partner Clarke Gayford, the host of a television show about fishing, will become a stay-at-home parent.
Ms. Ardern announced her pregnancy in January, just three months after a stunning upset victory that propelled her to the top of the center-left Labour Party and into the prime minister’s office in October.
Her pregnancy announcement prompted a national conversation about working mothers, and an international reckoning about the rarity of pregnant women in the world’s corridors of power.
In one interview before her election, Ms. Ardern told a reporter it was “unacceptable” to ask women if motherhood would interfere with their ability to succeed in the workplace.
The last leader to deliver a baby while in office was the late Benazir Bhutto, then prime minister of Pakistan, who gave birth to her second child, a daughter, in 1990.
That daughter, Bakhtawar Bhutto Zardari, congratulated Ms. Ardern on Twitter on Thursday.
In the 28 years since Ms. Zardari’s birth, several women earned their way into their country’s executive mansions and offices, but none spent time in the delivery room while in power.
While news reports at the time of Ms. Bhutto’s delivery said Pakistanis sang and danced in the streets with joy, she also faced criticism for having a second child. Opposition leaders said that “the country would be leaderless while she was hospitalized,” The New York Times reported at the time.
“There is no easygoing ‘mommy track’ for heads of state,” The Times wrote in 1990 about Ms. Bhutto’s uphill political battle.
Ms. Bhutto, who temporarily transferred power to her mother, the lawmaker Nusrat Bhutto, while in labor, announced that she was “back on the job” one day after her delivery.
Years after serving a second term as Pakistan’s prime minister, Ms. Bhutto was assassinated in 2007.
(Trivia buffs might want to note that Ms. Ardern’s baby was born on Ms. Bhutto’s birthday.)
In the United States, several politicians in recent years have made headlines for their pregnancies, including Sarah Palin, who as governor of Alaska delivered a baby with Down syndrome in 2008, and Sen. Tammy Duckworth of Illinois, whose pregnancy this year prompted Congress to change its rules about allowing babies and breast-feeding in the chamber.
The American ambassador to New Zealand, Scott Brown, congratulated Ms. Ardern both in English and in Maori, New Zealand’s indigenous language. “Tēnā koe i tō tamāhine. Ngā mihi mahana,” he said on Twitter (it means “Congratulations on the arrival of your new daughter, and best wishes”).
Congratulations also poured in from New Zealanders, some of whom said they were proud of what they saw as a symbolically important moment. “From one working Kiwi mum thank you for showing me I don’t have to be treated as less than anymore,” one Twitter user said.
Ms. Ardern’s popularity in New Zealand is due in part to her down-to-earth image. A spokeswoman for the prime minister said Thursday that Mr. Gayford had driven Ms. Ardern to the hospital in the couple’s own car.
The prime minister had been given a due date of June 17, and she only stopped flying to and from New Zealand’s capital, Wellington, on June 11. On advice from her doctors, she then worked from her home in Auckland, the country’s largest city, until the day before she went into labor.