A common practice of cutting tongue-tied babies is being labelled potentially dangerous, painful and frequently unnecessary.
The surgery is supposed to help babies who have trouble breastfeeding, but one senior doctor is questioning the evidence for that and says it's being massively over-used.
Canterbury mother Ruth*, gave birth to her son by emergency caesarean section 14 weeks ago.
The fact he had a tongue tie - a thin piece of skin joining the underside of his tongue to his lower jaw - was immediately clear to Ruth's midwife.
"He was pretty much being delivered and my midwife, who was going to be catching him, basically said, 'Oh, he's got a tongue tie.'"
It was not long before her son had trouble feeding.
"He would manage to latch and he would try and suck but as soon as he tried to suck he would just come off," Ruth said.
After two days of struggle, and feeding her baby Ruairi by syringe, his parents consulted a lactation specialist who performed the tongue tie procedure, which solved the problem.
But a Wellington specialist anaesthetist, Graham Sharpe, said the procedure was over-diagnosed, particularly by midwives.
He has written to the Health Minister David Clark demanding that untrained people stopped performing the procedure.
"The evidence shows, including a major … study, that in most cases children - we're talking about small babies, a week or two old - having difficulty feeding. And doing what is essentially a surgical procedure on these children is unnecessary and potentially dangerous," Mr Sharpe said.
The study, published in March last year, said tongue-tie or ankyloglossia, is present in four to 11 percent of newborns, and cited as a cause of poor breastfeeding and maternal nipple pain. It concluded that tongue tie surgery reduced mothers' nipple pain in the short-term.
There was no figures on who conducted the procedure, but midwives, GPs, dentists and surgeons can.
Dr Sharpe is clear on who he thought should conduct the procedure.
"If a child that age needs a surgical procedure because of a tongue problem that needs to be done by a trained surgeon in an appropriate facility, not done by a midwife."
The comments follow a decision from a Deputy Health and Disability Commissioner recently after an eight-day-old baby needed emergency care for bleeding following a tongue-tie release by a midwife.
Sue Calvert, from the Midwifery Council, said there was no data that showed how many tongue ties were done.
"But of course we would want to ensure that anyone who was performing the procedure has the knowledge and the skills."
Asked if the tongue-tie procedure improved feeding if there's a problem, Dr Calvert said "anecdotally" it seemed to "but we don't know if it's a long-term resolution".
She added that the council "would welcome exploration of this procedure".
Family doctor Alex Lyudin said in research published in June that 445 tongue ties were done at one Dunedin GP practice in 2013.
He said along with how common it was, he was also surprised and worried that almost a quarter had complications. In one case scar tissue that had become a new tie.
"We don't know what the rates of the tongue-tie cuts are, we don't know the reasons why people present initially, we don't know the risks involved and we don't know the outcome... None of this stuff has been studied."
Christchurch neonatal paediatrician Bronwyn Dixon said tongue ties could indeed harm babies.
"Risks of bleeding, harming other structures under the tongue, causing the baby an oral aversion and pain and distress."
Dr Dixon said careful assessment and coordination in Canterbury reduced the rate of tongue ties from 13 percent in 2015 to three and a half percent.
The Ministry of Health was unavailable to comment by the time this story was published.
*Ruth is not her real name.
- Reporting by Karen Brown, Health Correspondent