Helen Clark says New Zealand's reaction to a world leader's pregnancy is a sign of how far the country has come.
The former Prime Minister was among the first to congratulate Jacinda Ardern and Clarke Gayford on the birth of their first child on June 21.
"Today is a very happy day in the lives of Jacinda and Clarke as they welcome the arrival of their baby daughter," she said in a statement.
"My full congratulations go to both Jacinda and Clarke, and I wish them and their new baby all the best."
Ms Clark says Ms Ardern's pregnancy has been a landmark occasion for women's equality, and an inspiring indication that attitudes are finally shifting.
"For New Zealand, these events and the way our country has greeted them will be seen as inspirational by all who advocate for gender equality and women's empowerment.
"New Zealanders took the news of Jacinda's pregnancy in their stride," she says.
"This is a sign of our maturity as a country and its acceptance that combining career and family is a choice which women are free to make."
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She says Mr Gayford's intention to raise the baby as a stay-at-home dad after his partner returns to work in six weeks' time is also commendable.
"Let's also celebrate Clarke as a modern man who is happy to be the full time parent of a young child."
Ms Clark faced a good deal of sexism during her time as Labour leader and then Prime Minister from 1999 to 2008, including criticism over her decision not to have children.
"Attitudes have changed a lot on these issues since I first entered New Zealand politics, and that's a very good thing," she says.