I see a number of things which can masquerade as a behavioural sleep issue. One of the most common is tongue-tie. Not always obvious to the untrained eye, particularly if the tie is a posterior one, tongue-ties are sometimes missed even by midwives and other medical professionals. There is no doubt that a tongue-tie can affect a baby's ability to feed - although some babies manage surprisingly well. Often thought to be a problem that only arises in relation to breastfed babies (not least because a nursing mum may experience significant discomfort when feeding her tongue-tied infant), tongue-ties can, in fact, cause problems for a baby no matter how they are fed. However, even where a parent has suspicions, if their baby is gaining weight, the family may find it hard to make headway having this investigated.
When a tongue-tie goes undiagnosed, it can also affect sleep - in significant ways. Due to the sub-optimal resting position of a tethered-tongue, a child who has one may tend toward mouth-breathing and/or over-reliance on a dummy to sleep. Both of these, in a myriad of ways can drive night-waking and inhibit deep, restful sleep - which in turn can present as "just" a sleep problem. Add into the mix the numerous digestive issues and the colic and/or reflux that may accompany a tongue-tie and it becomes easy to see how a tongue-tied baby may find sleep very hard indeed.
To read more about tongue-tie, from Charlie - the very experienced IBCLC at Milk Matters, click here.