Ardern said deputy Prime Minister Winston Peters would serve as acting Prime Minister for six weeks after her baby was born.
"Mr Peters and I have a great relationship, and I know that together we'll make this period work...at the end of my leave I will resume all Prime Ministerial duties," she said in an emailed statement.
The 37-year-old Labour leader took the helm as Prime Minister in October, ending almost a decade of centre-right National Party rule.
Ardern went to the Philippines last year to other world leaders for the Association of Southeast Asian Summit in Manila.
source: news.abs-cbn.com
