Green Party politician Julie Anne Genter on Sunday announced on social media she had arrived at an Auckland hospital to be induced, and she had opted to go by bicycle.
"My partner and I cycled because there wasn't enough room in the car for the support crew," she said with accompanying photos.
"But it also put me in the best possible mood."
The news comes just weeks after New Zealand Prime Minister Jacinda Ardern returned to parliament following the birth of her daughter Neve.
Ms Genter is due to give birth at the same public hospital as Ms Ardern.
Also the country's associate transport minister, US-born Ms Genter, 38, is a well-known and outspoken cycling advocate.
Before she left the capital, she told AAP there was a sense of hopefulness among women seeing government ministers becoming mothers for the first time.
"I think that it's OK to celebrate it. I don't think we're at the point where we can say 'no big deal'," she said.
But having babies in office is far from new for Kiwi politicians.
Labour's Whetu Tirikatene-Sullivan was the first woman to give birth while an MP, in 1970. National's Ruth Richardson breastfed at work in 1983 and a child-care centre was established in parliament in the 1990s.
And while Senator Larissa Waters made headlines in Australia by feeding her daughter in the chamber, in New Zealand National's Katherine Rich did so during a debate in 2002.
A playground is currently being built on parliament's grounds amid a push by the Speaker of the House to make the precinct more family friendly.
