Reid-Meredith and her husband headed to Waitakere Hospital and after arriving they believed they were in for a long wait.
"Mum had only just started her knitting and we were settling in for a long night," she said.
But as she lay in the birthing pool the actress said she felt the need to push.
"My midwife checked again and said, 'Okay we are going to have this baby right now - in the pool'."
Her baby's heart rate started to show signs of distress and the couple became nervous, quickly moving Reid-Meredith from the pool to the bed, New Idea reports.
"It was surreal," said Meredith. "As the man you are holding back tears, but then you see your wife going hard and you have to stop yourself from crying and focus on what the job is - supporting her and helping him get here safely."
Soon after, Arlo David Meredith was born.
"We were all a little bit in shock because it had happened so quickly, but he came out and his eyes were wide open and he was fully present," said Reid-Meredith.
The soap star said she loves being a mum and has already taken her baby boy to the Shortland Street set a few times - a necessity after returning to work four weeks after the birth.
* Read more in the latest issue of New Idea.
- nzherald.co.nz