Prime Minister of New Zealand Jacinda Ardern is expecting her first child in June.
Ms Ardern says partner Clarke Gayford will stay home, as the primary caregiver.
"We're both really happy. We wanted a family, but weren't sure it would happen for us, which has made this news unexpected, but exciting."
Ms Adern said she has met with Winston Peters to share the news - and ask him to take over as Acting Prime Minister for six weeks.
"Yesterday, I met with Deputy Prime Minister Winston Peters to share the news and to ask him to take on the role of Acting Prime Minister for a period of six weeks, after our baby is born."
Ms Ardern said she and Mr Gayford are particularly lucky - they had been told they would need "help" to become parents.
"We first knew of my pregnancy on the October 13, but as many couples do in the early stages, we kept it to ourselves.
"From a personal perspective, I am so looking forward to my new role as a parent, but I am equally focused on my job and responsibilities as Prime Minister.
"While 2018 will be the year I become a mum, it will also be a year that the Government finishes our 100-day plan, and starts pursuing all of the priorities that will build a better New Zealand. I look forward to leading that work and having a slightly expanded family join me on that journey."