The farmers' experience in calving and lambing may yet be called on – Ardern has told the Herald she hopes to go to the Fieldays in the Waikato on June 15, just two days before her due date.
However, she said she did not know if she would make it to that date: "Looking at me, it's any time now."
Ardern said she planned to have a midwife and partner Clarke Gayford there for the birth.
Her mother would be "down south" but would be contacted as soon as labour began.
She said she would not switch off from work completely once the baby arrived and Winston Peters took over as Acting Prime Minister. She expected to be able to read her usual load of papers. "I'll just be based in one place a bit more. That'll be the difference."
Ardern also spoke about her pregnancy, saying she had not had unusual cravings other than for salt and vinegar chips.
She had a long list of names for the baby, whose gender Ardern and Gayford are not revealing ahead of time, but there were no favourites yet.
"It's not going well, I have to say. It's one of those things where Clarke is absolutely convinced it will come to us as soon as it arrives. I think we'll be sleep deprived and probably angry at each other so I don't think that's the best time to choose."
Her security staff were also on standby to ensure there were no mishaps, such as a slip on ice.
"They'd be very helpful in an ice scenario. At the moment I'm not sure I'd be able to get up on my own."