Getting a crying baby to quieten down and go to sleep quickly is the ultimate goal of any tired, sleep-deprived parent.
Now, a group of scientists from Japan believe they have found the best way to soothe a squalling infant within minutes.
Researchers from the RIKEN Centre for Brain Science in the Japanese city of Saitama say that carrying babies for a five-minute walk promotes sleep even in the daytime.
They recommended that parents or caregivers seeking to soothe a crying baby should attach the child snugly to their own bodies and support the baby’s head while taking a five-minute walk “on a flat and clear passage and at a steady pace, preferably without abrupt stops or turns”.
In addition, continuing to hold the child after they have fallen asleep for another five to eight minutes before laying them down in their cot could reduce the likelihood of the baby waking up.
The study, published in the Current Biology journal, found that babies who were laid down too soon after falling asleep in their mother’s arms were more likely to wake up and start crying again.
“During laydown, sleeping infants were alerted most consistently by the initiation of maternal detachment,” the study authors wrote.
The team, led by Dr Kumi Kuroda, tested four techniques on 21 babies between zero to seven months old during their study. These included laying babies in a cot, rocking them in a stroller, carrying them for a walk, and holding them while sitting down.
They concluded that the best way to soothe a baby to sleep is to adopt a “five-min carrying, five to eight-min sitting scheme”.
After a five minute walk while being held, five of the 11 babies (45.5 per cent) were asleep, with no crying infants left by the end of the task.
The study noted that two additional infants fell asleep within one minute of the sitting and holding step.
“When the infant falls asleep in the caregiver’s arms, withholding the laydown until another five to eight minutes have passed may reduce the probability of awakening the infant,” the researchers said.
The study acknowledged some limitations, including the lack of non-maternal caregivers involved, and called for more specific experiments to be carried out with larger sample groups.
It also noted that the recommended scheme does not address “long-term improvement of sleep regulation”, but provides “an immediate calming of infant cry and may be useful… on special occasions when regular sleep routines, breastfeeding, or pacifiers are not effective or available”.