"[The doctors] don't know for sure yet but they think it might have been the drinking I did the night before," Hape said. "I want to tell other mums not to drink, I don't want other mums to do what I have done and go through my experience."
Hape said she had consumed alcohol on other occasions but only because she didn't realise she was pregnant.
"Until one or two weeks ago I didn't even know I was pregnant, it was a shock," Hape said.
Hape's baby girl Cynthia Jane Williams weighed just 907g or nearly 2lb when she was born - the average full-term Kiwi baby weighs around 3500g.
"She is tiny but she is doing well," Hape said.
Last night, Cynthia was still in an incubator at Auckland City Hospital on oxygen and being fed her mother's expressed milk from a feeding tube.
Hape woke up with labour pains early last Saturday morning and drove to Kaeo Hospital but it was closed. She then went to the home of the midwife who had delivered her son Izayass, now 1.
"When I got there she called the ambulance. After 15 minutes they got there. When I got into the ambulance I could feel her pushing and five minutes later she was out."
Cynthia was airlifted to Auckland City Hospital for specialist care while Hape, her mother and mother-in-law drove.
"It was a long and painful trip," Hape said. "I was really scared and sore and I was just hoping I didn't get any phone calls [from the hospital]."
Hape and partner Michael Williams said baby Cynthia was doing well.
"They had her head scanned to make sure there was no bleeding in her head and she is eating properly now through a tube," Hape said.
Williams said he was looking forward to holding his daughter, who would be in an incubator for the next five weeks.
"We can't hold her just yet," Williams said. "She's hooked up to all the tubes and oxygen, she's only the size of my hand."
Williams said Cynthia was named after his older sister who was killed in a car crash when she was six months old.
"She died before I was born but my Mum is honoured her grand-daughter was named after her daughter," Williams said.
Auckland specialist Dr Alec Ekeroma said other activities during drinking could cause pre-term labour.
"Drinking alcohol in pregnancy is not advisable in any amount," Dr Ekeroma said.
"In early stages it can cause miscarriages and later it can cause problems like fetal alcohol syndrome which manifests in many ways."
Chief executive of New Zealand College of Midwives Karen Guilliland last night said the college would always advise women not to drink when pregnant.
"We say, if you want to keep risk-free, don't drink."
Hape's midwife Betty Ras described Cynthia's birth as a miracle but said it was an early labour that could probably have been avoided if Hape hadn't been drinking.
"This baby should still be in the womb and it could be. It is a nice story that the baby survived and is doing well but the [early] birth was avoidable," Ras said.
Ras said there was a huge problem with pregnant teenagers drinking.
"There are still young girls that want to try out lives and they want to drink but it is like drink-driving. You drink or you drive but not both." Ras said the teen pregnancy rate and drinking needed to be addressed.
This country has one of the highest teenage pregnancy rates, with around 60 in every 1000 young women getting pregnant in 2009. The rate was 50 in every 1000 20 years ago.
In 2009, 8650 young women under the age of 19 got pregnant - 108 were under the age of 15.
