The Prime Minister believes her baby news hit international headlines because there are still so few female leaders.

Commentary around the world exploded when Jacinda Ardern announced she'll become the second world leader to give birth while in power.

Jacinda Ardern told Mike Hosking it's still rare to see a woman in a country's top job.

She said there's only a small number of women at leaders' conferences and the number of child-bearing age is even smaller.

LISTEN ABOVE AS JACINDA ARDERN SPEAKS WITH MIKE HOSKING