Infant sleep training: rest easy?

Clinical question

What is the evidence for infant sleep training?

Bottom line

Sleep training improves infant sleep problems, with about 1 in 4 to 1 in 10 benefiting compared with no sleep training, with no adverse effects reported after 5 years. Maternal mood scales also statistically significantly improved; patients with the lowest baseline depression scores benefited the most.

Evidence

• Sleep training, or controlled crying, is where parents respond to their infant’s cry at increasing time intervals to allow independent settling.

• A 6-week RCT of 235 infants with a mean age of 7 months, with 2 or more awakenings per night on 5 or more nights per week, found the following¹:

  • -For sleep training versus safety education, there were statistically significant reductions in parental reports of severe infant sleep problems (4% vs 14%, number needed to treat [NNT] = 10); reductions in the number of infants with 2 or more diary-recorded awakenings per night (31% vs 60%, NNT = 4); and improved parent fatigue, sleep quality, and mood scale scores.

• A cluster RCT of 328 families reporting infant sleep problems (mean age 7 months) examined a tailored sleep intervention with sleep training versus usual care. The following was found for the intervention group²:

  • -At 10 months, there was statistically significant reduction in maternal reports of infant sleep problems (56% vs 68%, NNT = 9) and a non-significant reduction in mothers with depression (Edinburgh Postnatal Depression Scale score > 9; 28% vs 35%).

    • —Those with baseline scores above 9 had statistically significant numerical improvement in depression scale scores (subgroup analysis).

  • -At 2 years, there were fewer reported depression symptoms (15% vs 26%, NNT = 9).³

  • -At 5 years, there was no difference in any of 20 outcomes including child behaviour, relationships, and maternal mental health.⁴

• Recent smaller studies^5,6 and systematic reviews^7,8 support sleep training interventions for sleep and improved parental depression symptoms.⁷

Context

• Infants’ sleep problems are associated with parental depression,^9,10 psychological distress,¹¹ and poor health.¹¹

• Increased infant sleep is associated with good temperament, adaptability, and low distractibility.¹²

• Allowing the baby to “cry it out” was similarly effective, although parents often find this method more stressful.⁷

• Sleep training is simple and can begin at 6 months.

Implementation

There is no exact formula to sleep training. Most suggest putting the baby to bed while he or she is drowsy but still awake and leaving the room. If the baby cries, caregivers should not respond for 2 to 5 minutes. Responding involves brief reassurance without picking the baby up. The caregiver does not return for another 2 to 5 minutes. This interval is gradually extended by 2 to 5 minutes until the baby falls asleep. Although parents might initially find this method distressing, the infant’s sleep usually improves within 1 week.⁵