Berry removed the umbilical cord from around William's neck, and he began to cry.
"If it hadn't just popped off all right and he hadn't started breathing, it would have been a bit of a different story, not being somewhere with any medical professionals."
The family carried on to the hospital for William to be checked and Jess to be looked after.
"The whole thing was really overwhelming. Labour was only about four hours, start to finish, so I was pretty shocked by the whole thing."
Berry and her baby are back at their home on a farm at Queensberry, between Cromwell and Luggate.
Lake Dunstan midwife Suzanne MacIntosh said William was Berry's first baby, and the speed with which he was born was unexpected.
"It was quite unusual. She had what we would call a precipitate labour, which is very fast.
"It is a good thing, but it can be quite shocking for the mum, because it's full-on."
MacIntosh said in other circumstances, Berry might have been advised to have her baby at home, but living in a remote location, and it being in the early hours of the morning, driving to Alexandra appeared the better option.
Berry said she would have made it to Wanaka or Cromwell if there had been birthing units in either of those towns.
MacIntosh said publicity over the lack of facilities in the Upper Clutha had increased anxiety among expectant mothers.
She advised women to be well prepared and to be flexible.
The issue was not so much with babies arriving early, but "... the rapidness of the labour and the birth that takes them by surprise".
MacIntosh said there was nothing new about women in remote areas needing to be prepared for any eventuality, but what had changed was the increase in the number of women giving birth in the Cromwell-Wanaka area.
"The resources are not coping ... the midwives are overstretched."
Waitaki MP Jacqui Dean said "this latest incident is a shock, and demonstrates that the serious issues faced in Wanaka are not isolated to a one-off event".