She is only the second serving world leader to do so
New Zealand's prime minister Jacinda Ardern has become the first world leader in nearly 30 years to have a baby while in office.
The 37-year-old gave birth to a baby girl in Auckland City Hospital, becoming only the second world leader to do so while in office.
Benazir Bhutto had her second child in 1990 when she was prime minister of Pakistan.
"I'm sure we're going through all of the emotions new parents go through, but at the same time feeling so grateful for all the kindness and best wishes from so many people. Thank you," Ms Ardern said in a statement.
She added that both mother and daughter were doing well.
The politician and her partner Clarke Gayford (40) are yet to reveal the name of their baby - but said she arrived at 4.45pm weighing 7lbs 3oz.
A photo was posted to her Instagram account showing the baby wrapped in a blanket and clutching her little finger, with a caption saying: "Welcome to our village wee one."
Ms Ardern's due date was June 17th.
When announcing the pregnancy in January, Ms Ardern downplayed its significance: "Lots of people juggle a lot of things in their personal and private lives, and I'm not unusual in that. Plenty of women have multitasked before me, and I want to acknowledge that."
The birth capped an eventful year for Ms Ardern, who became prime minister last October - three months after inheriting the leadership of the Austrialian Labour Party when it was languishing in the polls.
When no party won sufficient support in the election to form a government, she was anointed prime minister by New Zealand First leader Winston Peters, the kingmaker in a three-party coalition also involving the Greens.
Mr Peters, who became Ms Ardern's deputy, is now acting prime minister while she takes six weeks maternity leave - although she will continue to be consulted on significant issues.
New Zealand opposition leader Simon Bridges offered his congratulations: "Being parents is a joy and a privilege and we are sure your new arrival will fill your lives with all the happiness our children have ours."