What might it look like

If tongue-tie division improves breast feeding, tens of thousands of babies a year might undergo it in the UK. Sooner or later things would go wrong – scissors would slip, and babies with clotting disorders would bleed heavily. That doesn’t mean we shouldn’t do it. Just that we should be sure it does more good than harm. What might a good quality trial look like?

Pre-trial

Someone with skills in systematic reviewing and no vested interest, should work with the Cochrane Collaboration to pull together the previous trial evidence and decide whether the question has already been answered. Presumably this is in hand.

Funders also need evidence that the association between tongue tie and breast feeding difficulties is real: a study of babies feeding nicely and babies with problems, with tongues all examined by an expert, without knowledge of how the breast feeding is going.  If tongue-tie is equally common in both groups we can stop worrying about it.  Has there been such a study?

Trial design

The trial must compare division with never dividing.  A trial comparing immediate with delayed division has two problems. It precludes measuring any long term outcomes; even duration of breast feeding, let alone anything like speech development or long term health, and it limits participation to staff and parents who already believe it works.  Measures of things like nipple pain and breast feeding scores are particularly susceptible to biased reporting, and may be reduced, at least in theory, because the baby is in pain from the division.  No-one wants to treat breast pain by hurting the baby.

Would any parent agree to their baby joining such a trial? Many will want one or other option, and recruitment will be a challenge. But many trials have been successfully conducted in other similarly polarised fields. It’ll need many centres, and many parent invitations. No-one would be forced to join.

Some babies in the “no division” group might get divided – it would be impossible and unethical to forbid division forever. To avoid biasing the results in favour of “no division” such babies would be analysed in their original group, by “intention to treat”. But to keep their numbers small, only parents who can give a reasonable commitment to stick with the allocated treatment should join. This will also slow recruitment.  

By the time independent randomisation, trial registration, data management, analysis by intention to treat, agreed sample sizes and defined endpoints that don’t get altered are included, the trial might cost £1M or so.  But let’s say each division costs £100 and 10,000 babies a year are eligible. If no trial is done the NHS could spend that every year for ever!

If the results are negative the trial would have saved thousands of babies from unnecessary surgery, and the money saved can be spent on other ways to help breast feeding. If division improves breast feeding, it can be rolled out properly, with incalculable health benefits.

Jim Thornton 

See also Leave Their Tongues Alone (here) and Another Tongue-Tie Trial (here)