Babies with tongue-ties rarely need surgery to help them feed, a US study suggests.
It found two-thirds of babies referred for the procedure did not need it and were able to feed with other support.
Tongue-tie occurs when the strip of skin connecting the tongue and the floor of the mouth is shorter than usual. It can affect feeding, though not always.
UK experts said the procedure could be avoided "with the right support".
'No real data'
Between 4% and 11% of babies are born with a tongue-tie, or ankyloglossia.
It can mean babies aren't able to open their mouths widely enough to breastfeed.
A simple procedure called a frenulectomy, where the tongue-tie is snipped, can be offered.
In very young babies, it can even be done under local anaesthetic.
The US study suggests the number of frenulectomies is increasing, from 1,200 in 1997 to 12,400 in 2012.
Figures from NHS Digital show at least 4,320 were carried out in England in 2015-16 - and that figure is likely to be an underestimate since it is such a quick procedure it might not always be recorded.
The US study, published in JAMA Otolaryngology - Head and Neck Surgery, looked at 115 babies, who on average were about a month old.
All had been referred for the surgical procedure - but 63% were able to successfully breastfeed with help from specialists, including speech and language therapists.
Dr Christopher Hartnick, from Massachusetts Eye and Ear hospital, who led the research, said: "We have seen the number of tongue-tie and upper lip tether release surgeries increase dramatically without any real strong data to show these are effective for breastfeeding."
NCT breastfeeding counsellor Jane Moffett said: "Many women experience challenges when feeding their babies during the first days and weeks.
"In some cases, this may be due to tongue-tie.
"There is limited evidence to indicate which babies need a tongue-tie division and which do not.
"Services also vary considerably across the UK, with some areas having no NHS provision and concerns about over-diagnosis in others.
"If you think your baby has tongue-tie, or are worried that he or she isn't feeding properly, get in touch with a breastfeeding counsellor, midwife or health visitor.
"Getting support early can make all the difference."
Prof Mary Fewtrell, from the Royal College of Paediatrics and Child Health, said: "For some, tongue-tie can be the cause of poor breastfeeding and maternal nipple pain and the procedure can correct the restriction to tongue movement and allow more effective breastfeeding for baby, and comfort for mum.
"However, parents need good breastfeeding support and advice before considering surgery because, as this study shows, it can sometimes be avoided with the right support.
"Whilst this new study sheds some light on this issue, as yet, we do not have enough data from good quality trials to know what is best for breastfeeding outcomes."