''There's your baby, the heart is fine, see you later; that's how we found out - it's funny,'' Mr de Lange said.
The couple had talked about having a child, ''but we weren't suppose to get it this fast'', he said.
Ms Schellinger said the pregnancy meant they had to change their plans for extreme sports, such as bungy jumping and jet-boating, but they would go surfing.
The couple were travelling with their dog Joepie in a Land Rover, which they shipped from the Netherlands.
It took 10 weeks.
Joepie, a 10-year-old stabyhoun Frisian pointer, was flown to Auckland, where he was quarantined before they started their journey.
Joepie travelled everywhere with the couple.
''We made a promise to him when he was very young that we would never put him in a kennel.''
Their Australian itinerary included travelling from Brisbane to Perth before heading home for the birth in November.
Mr de Lange is self-employed and advises his Dutch clients on how to maximise their internet marketing.
He had been working remotely while in New Zealand.
''A lot of my clients don't even know I'm here,'' Mr de Lange said.
The couple had slept in a tent most nights in New Zealand, but Queenstown and Dunedin had been too cold so they stayed in motels.
They were enjoying the ''positive energy'' of New Zealanders.