Babies do sleep better if you leave them to cry - scientists

Science says that babies have a better sleep when they cry themselves tired. Photo / iStock

It's a dilemma faced by many new parents: do they get up in the night to comfort their crying babies - or let them sob themselves to sleep?

Now scientists say babies sleep more soundly and wake less often in the night if they are left to soothe themselves.

In tests, sleep experts found that the tactic also led to other family members getting more shut-eye.

Associate Professor Michael Gradisar assessed two "controlled crying" techniques - as well as leaving parents to comfort their babies whenever they wanted.

He found that controlled crying methods had no detrimental effects on either baby or parent. Professor Gradisar said: "It's natural for parents to worry about having their babies cry at bedtime.

"While it's well documented that sleep deprivation can cause family distress, including maternal depression, we're hoping these results will add another element to how parents view their responses and how they manage their own and their babies' sleep behaviour."

He tested 43 babies, aged 6 to 16 months, which were suffering night-time sleep troubles.

One group used controlled crying - or "graduated extinction" - designed to let babies fall asleep on their own.

Parents in this group had to wait a few minutes before responding to their crying babies.
They were allowed to comfort but not pick up the baby. A second method tested "bedtime fading", which sees parents gradually delaying bed-time.

This group put off bedtime initially by 15 minutes - with the option of increasing it if problems persisted.

A control group were simply given information on healthy sleeping habits. After three months, the researchers found babies in both sleep-training groups were dozing off an average of 10 to 13 minutes faster. Meanwhile there was little difference in the control group. Babies in the controlled-crying group slept better during the night, waking up less frequently - just once or twice on average compared with three times at the start of the study period. Stress levels for mothers dropped in the first month and there was no sign it caused stress to the infants, Professor Gradisar said. Saliva samples showed levels of the "stress hormone" cortisol also fell slightly in babies.

There were no significant differences in emotional or behavioural problems or in attachment issues at a follow-up check a year later.

Professor Gradisar, of Flinders University, Australia, also suggested trying the delayed bedtimes technique first before progressing to the controlled crying method.

He said: 'We hope parents of children of 6 to 16 months can become more aware of bedtime fading which helps babies fall asleep at the start of the night.

"It may not resolve awakenings during the night so if a child is waking up several times a night, then there is now some more evidence that graduated extinction is a technique that may not be harmful to their child."