The 36-year-old Auckland Central MP issued a statement saying the news was devastating for her and her family.
On her Facebook page, Ms Kaye said she informed Prime Minister John Key on Friday and would be taking leave of absence from her ministerial roles.
"I feel so lucky to have such an amazing family and group of friends who are giving me buckets of love and have been so strong helping me work through this," she wrote.
"I also want to acknowledge the PM who has been hugely caring and supportive."
