New Zealand's minister for women has cycled herself to a birthing unit as she prepares to have her first child.

Green Party politician Julie Anne Genter posted a picture on Instagram saying she had arrived at Auckland City hospital to be induced – and had travelled by bicycle.

“Beautiful Sunday morning for a bike ride, to the hospital, for an induction to finally have this baby. This is it, wish us luck!

"My partner and I cycled because there wasn't enough room in the car for the support crew," she wrote.

"But it also put me in the best possible mood."

Genter, who was 42-weeks pregnant, said the ride was mostly downhill.

The news comes just weeks after the country’s prime minister Jacinda Ardern returned to parliament following the birth of her daughter Neve.

Genter is due to give birth at the same public hospital as Ardern.

Also the country's associate transport minister, Genter, 38, is a well-known and outspoken cycling advocate.

Before she left the capital, she said 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.

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.