"Obviously it is hard to gauge any cognitive functions at his age, but we are confident of a recovery. Physically he is capable and healthy."
Carter was discharged from hospital while Preston was in New Zealand for his mother's funeral, but the baby returned to the ward within days with a viral infection.
"Since then Carter has put on weight and is developing seemingly as he should," Preston said.
"We moved from our house into a one-level apartment. It was very strange feeling to be in the house where it happened. Especially when carrying Carter down the stairs. Now life is back to where we were."
Preston and Nguyen were enjoying the ordinary challenges of a newborn.
"We have had a difficult time training him to sleep. From being in hospital and woken every three hours, his sleep pattern has been hard to break."
Preston and his family wanted something good to come from the tragedy so they launched a trust in Ferne's memory to benefit the hospital. Facilities are so basic that some parents must take shifts manually pumping their children's ventilators because the hospital does not have automated equipment.
"There is a serious capacity problem at the hospital, especially as this year being the Year of the Dragon is popular to give birth.
"I am not sure how we will contribute the funds at this stage. We will close the fund on January 19 - Mum's birthday - then we'll start the conversation with the hospital and let the ideas evolve," he said.
The fund had reached over $60,000 this week.
Preston's brother Stefan said Ferne's Birkdale home was to be auctioned today. He said dealing with the many "treasures" she'd collected over the years was heartbreaking.
Donations to the Julie Ferne Memorial Trust can be made at any branch of the ASB Bank or directly into the account: 12-3198-0065427-00.
