Dear Sir,

We thank the author of this letter(1) for the comments. We would like to make a number of points in response. The first is regarding the type of intervention utilised. We would like to refer interested readers to our published review, in which we defined a behavioural intervention as “a practice implemented by a parent or primary care-giver with the primary aim of improving infant sleep. These behaviours typically include ways of settling the baby at sleep time, how and when to respond to infant crying or signalling during a period of sleep, and other strategies to promote undisturbed sleep”.(2) This is a narrow and clear definition. As most clinicians would be aware, the presentation of each infant and their parents is unique. The precise plan that is given to parents varies according to the infant’s age, weight, current feeding habits (e.g. overnight feeds, quantity of solids) and the parents’ attitudes toward settling behaviours and degree of comfort with extinction-based strategies. As the specific advice was individualised for each family, we cannot easily define the specific intervention in any more detail than has been given. For example, the precise intervention for a four-month-old still requiring overnight feeds would be different from that for an 11-month-old infant who is well established on solids and of healthy weight.

The intervention, as described in numerous papers,(3-5) did not assume that “the infant is not distressed in any way”. We merely commented on the possibility that fatigue may be a reason for distress, particularly at the end of the day. As we have stated, “fatigue interferes with the performance of learned skills (i.e. sleep achievement), and tearfulness in a well-fed neonate may reflect fatigue rather than pain”.(3) We would be interested to read any published research providing evidence on how to successfully differentiate among babies’ cries.

With regard to the second point, we do not disagree that many parents find extinction techniques difficult, and have acknowledged this previously.(2) In our clinic, it is quite apparent when parents are not willing to use such strategies and we offer modified techniques in such cases. We argue that this is not a biased view: we presented the figures for attrition, acknowledged the difficulty some parents had,(2) and did not attempt to conclude that mothers who failed to complete the second interview had the same improvements as those who completed the study.(5) In over 30 years of clinical work in this field, we can report that many parents do not return, contrary to the hypothesis in the author’s letter, because the intervention has indeed been successful. As the infant is sleeping through the night within one week, the parents have no reason to return.

As authors and parents, our experience in practice has shown how dramatically (and quickly) the well-being of an overtired baby and exhausted mother can change for the better. We wish to provide information to parents; the decision to implement such techniques is then up to them.

Yours sincerely,

Blunden S. Comment on: The joy of parenting: infant sleep intervention to improve maternal emotional well-being and infant sleep. Singapore Med J. 2017;58:167.
Crichton GE, Symon B. Behavioral management of sleep problems in infants under 6 months - what works?. J Dev Behav Pediatr. 2016;37:164-71.
Symon B, Marley J, Martin A, Norman E. Effect of a consultation teaching behaviour modification on sleep performance in infants: a randomised controlled trial. Med J Aust. 2005;182:215-8.
Symon B, Bammann M, Crichton G, Lowings C, Tucsok J. Reducing postnatal depression, anxiety and stress using an infant sleep intervention. BMJ Open. 2012;2:e001662.
Symon B, Crichton GE. The joy of parenting: infant sleep intervention to improve maternal emotional well-being and infant sleep. Singapore Med J. 2016;58:50-4.